Reportable Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Dec. 28, 2014 item	Dec. 29, 2013	Sep. 28, 2014
Financial information concerning reportable segments
Number of renamed reportable segments	2ttek_NumberOfRenamedReportableSegments
Revenue	$ 581,056us-gaap_SalesRevenueServicesNet	$ 645,848us-gaap_SalesRevenueServicesNet
Operating income (loss)	36,612us-gaap_OperatingIncomeLoss	43,718us-gaap_OperatingIncomeLoss
Depreciation	6,864us-gaap_Depreciation	7,129us-gaap_Depreciation
Total assets	1,696,136us-gaap_Assets		1,776,404us-gaap_Assets
Inter-segment elimination
Financial information concerning reportable segments
Revenue	(18,715)	(24,827)
Corporate
Financial information concerning reportable segments
Operating income (loss)	(7,520)	(7,636)
Depreciation	1,293	754
Corporate
Financial information concerning reportable segments
Total assets	895,002		929,620
WEI \| Operating segment
Financial information concerning reportable segments
Revenue	233,668	229,330
Operating income (loss)	21,832	22,225
Depreciation	1,232	1,414
Total assets	267,615		302,877
RME \| Operating segment
Financial information concerning reportable segments
Revenue	331,673	359,263
Operating income (loss)	25,720	33,260
Depreciation	3,679	4,163
Total assets	421,493		442,911
RCM \| Operating segment
Financial information concerning reportable segments
Revenue	34,430	82,082
Operating income (loss)	(3,420)	(4,131)
Depreciation	660	798
Total assets	$ 112,026		$ 100,996

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Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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+ References

No definition available.

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