Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 26, 2016	Jun. 28, 2015	Jun. 26, 2016	Jun. 28, 2015
Condensed Consolidated Statements of Comprehensive Income (Loss)
Net income including noncontrolling interests	$ 25,690	$ 26,252	$ 52,669	$ 70,909
Other comprehensive income, net of tax
Foreign currency translation adjustments	9,044	11,676	19,149	(56,514)
(Loss) gain on cash flow hedge valuations	(524)	621	(11)	(1,376)
Other comprehensive income (loss), net of tax	8,520	12,297	19,138	(57,890)
Comprehensive income including noncontrolling interests	34,210	38,549	71,807	13,019
Net loss (income) attributable to noncontrolling interests	4	(46)	9	(111)
Foreign currency translation adjustments, net of tax	8	14	(5)	118
Comprehensive income (loss) attributable to noncontrolling interests	12	(32)	4	7
Comprehensive income attributable to Tetra Tech	$ 34,222	$ 38,517	$ 71,811	$ 13,026