Condensed Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 30, 2014	Mar. 31, 2013	Mar. 30, 2014	Mar. 31, 2013
Condensed Consolidated Statements of Comprehensive Income
Net income including noncontrolling interests	$ 31,909	$ 24,872	$ 59,236	$ 51,268
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax	(15,684)	(12,154)	(37,819)	(17,767)
(Loss) gain on cash flow hedge valuations, net of tax	(386)	(28)	439	93
Other comprehensive loss	(16,070)	(12,182)	(37,380)	(17,674)
Comprehensive income including noncontrolling interests	15,839	12,690	21,856	33,594
Net income attributable to noncontrolling interests	(200)	(52)	(213)	(225)
Foreign currency translation adjustments, net of tax	34	20	73	33
Comprehensive income attributable to noncontrolling interests	(166)	(32)	(140)	(192)
Comprehensive income attributable to Tetra Tech	$ 15,673	$ 12,658	$ 21,716	$ 33,402