Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 29, 2013
Consolidated Statements of Comprehensive Income (Loss)
Net income (loss) including noncontrolling interests	$ 39,228	$ 108,675	$ (1,506)
Other comprehensive loss, net of tax:
Foreign currency translation adjustments	(98,287)	(45,480)	(28,817)
Gain (loss) on cash flow hedge valuations	(2,489)	1,029	(389)
Other comprehensive loss, net of tax	(100,776)	(44,451)	(29,206)
Comprehensive income (loss) including noncontrolling interest	(61,548)	64,224	(30,712)
Net income attributable to noncontrolling interests	(154)	(409)	(635)
Foreign currency translation adjustments, net of tax	143	55	47
Comprehensive income attributable to noncontrolling interests	(11)	(354)	(588)
Comprehensive income (loss) attributable to Tetra Tech	$ (61,559)	$ 63,870	$ (31,300)