Document And Entity Information	6 Months Ended
Document And Entity Information	Mar. 31, 2013	Apr. 30, 2013
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q2
Entity Registrant Name	ESCO TECHNOLOGIES INC
Entity Central Index Key	0000866706
Current Fiscal Year End Date	--09-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		26,436,497

Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Consolidated Statements Of Operations [Abstract]
Net sales	$ 166,178	$ 173,863	$ 311,443	$ 326,788
Costs and expenses:
Cost of sales	110,681	105,967	204,719	198,688
Selling, general and administrative expenses	45,751	47,944	92,690	96,634
Amortization of intangible assets	4,203	3,254	7,703	6,407
Interest expense, net	668	470	1,231	961
Other expenses (income), net	1,330	(376)	1,258	(848)
Total costs and expenses	162,633	157,259	307,601	301,842
Earnings before income taxes	3,545	16,604	3,842	24,946
Income tax expense	1,986	6,402	2,037	9,537
Net earnings	$ 1,559	$ 10,202	$ 1,805	$ 15,409
Earnings per share:
Basic - Net earnings	$ 0.06	$ 0.38	$ 0.07	$ 0.58
Diluted - Net earnings	$ 0.06	$ 0.38	$ 0.07	$ 0.57

Consolidated Statements Of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Consolidated Statements Of Comprehensive Income (Loss) [Abstract]
Net earnings	$ 1,559	$ 10,202	$ 1,805	$ 15,409
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(1,786)	1,013	(811)	(543)
Pension adjustment			(109)
Interest rate swap adjustment				2
Total other comprehensive income (loss), net of tax	(1,786)	1,013	(920)	(541)
Comprehensive income (loss)	$ (227)	$ 11,215	$ 885	$ 14,868

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Sep. 30, 2012
ASSETS
Cash and cash equivalents	$ 35,880	$ 30,215
Accounts receivable, net	141,154	151,051
Costs and estimated earnings on long-term contracts, less progress billings of $15,214 and $30,534, respectively	15,523	14,567
Inventories	117,497	108,061
Current portion of deferred tax assets	22,706	22,313
Other current assets	38,699	17,237
Total current assets	371,459	343,444
Property, plant and equipment, net	80,699	75,876
Intangible assets, net	244,392	231,473
Goodwill	387,630	361,280
Other assets	21,327	21,680
Total assets	1,105,507	1,033,753
LIABILITIES AND SHAREHOLDERS' EQUITY
Current maturities of long-term debt	51,698	50,000
Accounts payable	50,237	54,049
Advance payments on long-term contracts, less costs incurred of $39,186 and $31,534, respectively	15,967	21,700
Accrued salaries	21,111	25,717
Current portion of deferred revenue	40,149	24,920
Accrued other expenses	30,176	27,819
Total current liabilities	209,338	204,205
Pension obligations	33,984	35,480
Deferred tax liabilities	92,790	88,675
Other liabilities	22,037	9,080
Long-term debt	126,000	65,000
Total liabilities	484,149	402,440
Shareholders' equity:
Preferred stock, par value $.01 per share, authorized 10,000,000 shares
Common stock, par value $.01 per share, authorized 50,000,000 shares, issued 30,147,204 and 30,044,486 shares, respectively	302	300
Additional paid-in capital	282,328	279,392
Retained earnings	439,150	441,566
Accumulated other comprehensive loss, net of tax	(26,298)	(25,378)
Total shareholders' equity before treasury stock	695,482	695,880
Less treasury stock, at cost: 3,714,607 and 3,453,249 common shares, respectively	(74,124)	(64,567)
Total shareholders' equity	621,358	631,313
Total liabilities and shareholders' equity	$ 1,105,507	$ 1,033,753

Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2013	Sep. 30, 2012
Consolidated Balance Sheets [Abstract]
Costs and estimated earnings on long-term contracts, progress billings	$ 15,214	$ 30,534
Advance payments on long-term contracts, costs incurred	$ 39,186	$ 31,534
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	30,147,204	30,044,486
Treasury stock, shares	3,714,607	3,453,249

Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net earnings	$ 1,805	$ 15,409
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	13,796	12,327
Stock compensation expense	2,434	2,261
Changes in current assets and liabilities	(27,470)	(16,343)
Inventory write down	5,045
Effect of deferred taxes	3,722	140
Change in deferred revenue and costs, net	3,811	(1,580)
Pension contributions	(1,755)	(1,340)
Other	676	(9)
Net cash provided by operating activities	2,064	10,865
Cash flows from investing activities:
Acquisition of businesses, net of cash acquired	(28,247)	(1,345)
Additions to capitalized software	(7,665)	(6,751)
Capital expenditures	(10,117)	(6,152)
Net cash used by investing activities	(46,029)	(14,248)
Cash flows from financing activities:
Proceeds from long-term debt	77,698	39,365
Principal payments on long-term debt	(15,000)	(38,000)
Dividends paid	(4,244)	(4,268)
Purchases of common stock into treasury	(9,703)
Proceeds from exercise of stock options	1,739	(326)
Other	(49)	68
Net cash provided (used) by financing activities	50,441	(3,161)
Effect of exchange rate changes on cash and cash equivalents	(811)	(543)
Net increase (decrease) in cash and cash equivalents	5,665	(7,087)
Cash and cash equivalents, beginning of period	30,215	34,158
Cash and cash equivalents, end of period	$ 35,880	$ 27,071

Basis Of Presentation	6 Months Ended
Basis Of Presentation	Mar. 31, 2013
Basis Of Presentation [Abstract]
Basis Of Presentation	1. BASIS OF PRESENTATION The accompanying consolidated financial statements, in the opinion of management, include all adjustments, consisting of normal recurring accruals, necessary for a fair presentation of the results for the interim periods presented. The consolidated financial statements are presented in accordance with the requirements of Form 10-Q and consequently do not include all the disclosures required for annual financial statements by accounting principles generally accepted in the United States of America (GAAP). For further information, refer to the consolidated financial statements and related notes included in the Company's Annual Report on Form 10-K for the fiscal year ended September 30, 2012. The Company's business is typically not impacted by seasonality; however, the results for the three and six-month periods ended March 31, 2013 are not necessarily indicative of the results for the entire 2013 fiscal year. References to the second quarters of 2013 and 2012 represent the fiscal quarters ended March 31, 2013 and 2012, respectively. In preparing the financial statements, the Company uses estimates and assumptions that may affect reported amounts and disclosures. The Company regularly evaluates the estimates and assumptions related to the allowance for doubtful trade receivables, inventory obsolescence, warranty reserves, value of equity-based awards, goodwill and purchased intangible asset valuations, asset impairments, employee benefit plan liabilities, income tax liabilities and assets and related valuation allowances, uncertain tax positions, and claims, litigation and other loss contingencies. Actual results could differ from those estimates.

Acquisitions	6 Months Ended
Acquisitions	Mar. 31, 2013
Acquisitions [Abstract]
Acquisitions	2. ACQUISITIONS On December 31, 2012, the Company acquired the assets of Metrum Technologies LLC (Metrum) for a purchase price of $25 million in cash plus contingent consideration based on future revenues over the next four years. Metrum is a leading provider of wireless public network communications products for electric utility customers and also offers communications products and devices for distribution automation and demand response applications. Metrum's operating results, since the date of acquisition, are included within Aclara Technologies LLC in the USG segment. The Company recorded approximately $25 million of goodwill, $11.2 million of amortizable identifiable intangible assets consisting primarily of customer relationships and patents / technology and contingent consideration valued at $13.7 million. On December 21, 2012, the Company acquired the assets of Felix Tool & Engineering, Inc. (Felix Tool) for a purchase price of $1.2 million in cash. Felix Tool is engaged in the design, manufacture and sale of customized perforated tubes for filtration applications in the aerospace and fluid power industry. The purchase price was allocated to property, plant and equipment and inventory based on fair market value at the date of acquisition and there were no intangible assets recorded upon the transaction. The operating results for Felix Tool, since the date of acquisition, are included within PTI Technologies Inc. in the Filtration segment. On December 10, 2012, the Company acquired the assets of Finepoint Marketing, Inc. (Finepoint) for a purchase price of $2.5 million. Finepoint is the electric power industry's leading conference provider focused on medium and high voltage circuit breakers, as well as related substation and switchgear topics. The operating results for Finepoint, since the date of acquisition, are included within Doble Engineering Company in the USG segment. The Company recorded approximately $1.3 million of goodwill as a result of the transaction and $1.2 million of amortizable identifiable intangible assets consisting of customer relationships.

Income Tax Expense	6 Months Ended
Income Tax Expense	Mar. 31, 2013
Income Tax Expense [Abstract]
Income Tax Expense	8. INCOME TAX EXPENSE The second quarter 2013 effective income tax rate was 56.0% compared to 38.6% in the second quarter of 2012. The effective income tax rate in the first six months of 2013 was 53.0% compared to 38.2% in the prior year period. The income tax expense in the second quarter and first six months of 2013 was unfavorably impacted by an adjustment to the foreign valuation allowance increasing the second quarter and year-to-date effective tax rate by 50.1% and 46.2%, respectively. The income tax expense in the second quarter and first six months of 2013 was favorably impacted by the extension of the research credit as a result of the American Taxpayer Relief Act of 2012 reducing the second quarter and year-to-date effective tax rate by 27.6% and 25.5%, respectively. The income tax expense in the second quarter and first six months of 2012 was unfavorably impacted by a purchase accounting adjustment increasing the second quarter and year-to-date effective tax rate by 3.2% and 2.1%, respectively. The Company estimates the fiscal 2013 effective tax rate will be approximately 37%. There was no material change in the unrecognized tax benefits of the Company during the three-month period ended March 31, 2013. The Company does not anticipate a material change in the amount of unrecognized tax benefits in the next twelve months.

Recently Issued Accounting Pronouncements	6 Months Ended
Recently Issued Accounting Pronouncements	Mar. 31, 2013
Recently Issued Accounting Pronouncements [Abstract]
Recently Issued Accounting Pronouncements	10. RECENTLY ISSUED ACCOUNTING PRONOUNCEMENTS In July 2012, the FASB issued Accounting Standards Update No. 2012-02, Intangibles – Goodwill and Other (Topic 350): Testing Indefinite-Lived Intangible Assets for Impairment (ASU 2012-02). This ASU updates the rules on testing indefinite-lived intangible assets other than goodwill for impairment and permits the option to perform a qualitative assessment of the fair value of indefinite-lived intangible assets. This update is effective for fiscal years, and interim periods within those years, beginning after September 15, 2012 and is not expected to have a material impact on the Company's financial statements.

Acquisitions (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012 Metrum Technologies LLC [Member]	Dec. 21, 2012 Felix Tool & Engineering, Inc. [Member]	Dec. 10, 2012 Finepoint Marketing, Inc. [Member]
Business Acquisition [Line Items]
Purchase price	$ 25.0	$ 1.2	$ 2.5
Period which future revenues for contingent consideration are based	4 years
Goodwill as a result of the transaction	25.0		1.3
Amortizable identifiable intangible assets	11.2	0	1.2
Contingent consideration	$ 13.7

Earnings Per Share (EPS) (Narrative) (Details) (USD $)	3 Months Ended
Earnings Per Share (EPS) (Narrative) (Details) (USD $)	Mar. 31, 2013	Mar. 31, 2012
Earnings Per Share [Line Items]
Common stock outstanding, but were not included in the computation of diluted EPS	0	124,654
Minimum [Member]
Earnings Per Share [Line Items]
Weighted average price of securities excluded from computation of earnings per share		$ 35.69
Maximum [Member]
Earnings Per Share [Line Items]
Weighted average price of securities excluded from computation of earnings per share		$ 45.20
Restricted Shares [Member]
Earnings Per Share [Line Items]
Common stock outstanding, but were not included in the computation of diluted EPS	192,000	232,000

Share-Based Compensation (Schedule Of Stock Options Awarded Under The Option Plans) (Details) (USD $) In Millions, except Share data, unless otherwise specified	6 Months Ended
	Mar. 31, 2013
Share-Based Compensation [Abstract]
Stock options, Shares, October 1, 2012	125,816
Stock options Granted, Shares
Stock options Exercised, Shares	(50,816)
Stock options Cancelled / Expired, Shares	(5,850)
Stock options, Shares, March 31, 2013	69,150
Stock options Exercisable, Shares	69,150
Stock options Estimated Weighted Average Price, October 1, 2012	$ 36.29
Stock options Granted, Estimated Weighted Average Price
Stock options Exercised, Estimated Weighted Average Price	$ 34.68
Stock options Cancelled / Expired, Estimated Weighted Average Price	$ 37.24
Stock options Estimated Weighted Average Price, March 31, 2013	$ 37.40
Stock options Exercisable, Estimated Weighted Average Price	$ 37.40
Stock options Exercised, Aggregate Intrinsic Value	$ 0.3
Stock options Outstanding at March 31, 2013, Aggregate Intrinsic Value	0.2
Stock options Exercisable at March 31, 2013, Aggregate Intrinsic Value	$ 0.2
Stock options Outstanding at March 31, 2013, Weighted Average Remaining Contractual Life	6 months

Inventories (Schedule Of Inventories) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Sep. 30, 2012
Inventories [Abstract]
Finished goods	$ 40,706	$ 30,250
Work in process, including long-term contracts	34,223	30,372
Raw materials	42,568	47,439
Total inventories	$ 117,497	$ 108,061

Business Segment Information (Schedule Of Net Sales And Earnings Before Income Tax) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 segment	Mar. 31, 2012
Segment Reporting Information [Line Items]
Number of reporting segments			3
Net sales	$ 166,178	$ 173,863	$ 311,443	$ 326,788
Consolidated EBIT	4,213	17,074	5,073	25,907
Less: Interest expense	(668)	(470)	(1,231)	(961)
Earnings before income taxes	3,545	16,604	3,842	24,946
USG [Member]
Segment Reporting Information [Line Items]
Net sales	72,731	74,475	135,349	144,824
Consolidated EBIT	(2,423)	9,101	(4,631)	14,067
Test [Member]
Segment Reporting Information [Line Items]
Net sales	39,821	50,483	76,116	89,837
Consolidated EBIT	2,559	4,775	3,078	6,722
Filtration [Member]
Segment Reporting Information [Line Items]
Net sales	53,626	48,905	99,978	92,127
Consolidated EBIT	10,894	9,468	19,695	17,704
Corporate (Loss) [Member]
Segment Reporting Information [Line Items]
Consolidated EBIT	$ (6,817)	$ (6,270)	$ (13,069)	$ (12,586)

Debt (Narrative) (Details) (USD $)	0 Months Ended	6 Months Ended
Debt (Narrative) (Details) (USD $)	May 14, 2012	Mar. 31, 2013	Sep. 30, 2012	Mar. 31, 2012	Sep. 30, 2011
Debt Instrument [Line Items]
Revolving credit facility		$ 330,000,000
Available to borrow under the credit facility		260,000,000
Option amount to increase credit facility		250,000,000
Cash on hand		35,880,000	30,215,000	27,071,000	34,158,000
Outstanding borrowings under the credit facility		176,000,000
Outstanding letters of credit		13,900,000
Number of lenders	8
Percentage of foreign subsidiaries' share equity		65.00%
Minimum [Member]
Debt Instrument [Line Items]
Incremental term loan		25,000,000
Credit facility fees		0.175%
Maximum [Member]
Debt Instrument [Line Items]
Incremental term loan		250,000,000
Credit facility fees		0.35%
JPMorgan Chase Bank N.A. [Member]
Debt Instrument [Line Items]
Revolving credit facility	$ 450,000,000
Revolving credit facility period	5 years

Debt (Schedule Of Debt) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Sep. 30, 2012
Debt [Abstract]
Total borrowings	$ 177,698	$ 115,000
Short-term borrowings and current portion of long-term debt	(51,698)	(50,000)
Total long-term debt, less current portion	$ 126,000	$ 65,000

Income Tax Expense (Details)	3 Months Ended		6 Months Ended
Income Tax Expense (Details)	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Income Tax Expense [Line Items]
Effective income tax rate	56.00%	38.60%	53.00%	38.20%
Increase in effective tax rate		3.20%		2.10%
Estimated annual effective income tax rate			37.00%
Foreign Valuation Allowance [Member]
Income Tax Expense [Line Items]
Increase in effective tax rate	50.10%		46.20%
American Taxpayer Relief Act Of 2012 [Member]
Income Tax Expense [Line Items]
Decrease in effective tax rate	27.60%		25.50%