Condensed Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
Dec. 28, 2014	Dec. 29, 2013
Consolidated Statements of Comprehensive Income
Net income including noncontrolling interests	$ 25,646us-gaap_ProfitLoss	$ 27,327us-gaap_ProfitLoss
Other comprehensive income, net of tax
Foreign currency translation adjustments	(24,510)	(22,135)
(Loss) gain on cash flow hedge valuations, net of tax	(480)	826
Other comprehensive loss, net of tax	(24,990)	(21,309)
Comprehensive income including noncontrolling interests	656	6,018
Net income attributable to noncontrolling interests	(71)	(12)
Foreign currency translation adjustments	(59)	38
Comprehensive (income) loss attributable to noncontrolling interests	(130)	26
Comprehensive income attributable to Tetra Tech	$ 526us-gaap_ComprehensiveIncomeNetOfTax	$ 6,044us-gaap_ComprehensiveIncomeNetOfTax

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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