Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Revenue	$ 825,793	$ 764,795	$ 2,265,846	$ 2,224,805
Gross profit	117,987	109,594	313,141	295,165
Selling, general and administrative expenses	(53,146)	(53,906)	(145,016)	(146,254)
Contingent consideration – fair value adjustments	0	(192)	(28)	(2,110)
Income from operations	64,841	55,496	168,097	146,801
Interest expense	(3,546)	(4,345)	(9,607)	(11,597)
Income before income tax expense	61,295	51,151	158,490	135,204
Income tax expense	(12,044)	(17,806)	(11,263)	(27,060)
Net income	49,251	33,345	147,227	108,144
Net income attributable to noncontrolling interests	(18)	(23)	(86)	(62)
Net income attributable to Tetra Tech	$ 49,233	$ 33,322	$ 147,141	$ 108,082
Earnings per share attributable to Tetra Tech:
Basic (in dollars per share)	$ 0.90	$ 0.60	$ 2.67	$ 1.94
Diluted (in dollars per share)	$ 0.88	$ 0.59	$ 2.63	$ 1.91
Weighted-average common shares outstanding:
Basic (in shares)	54,819	55,537	55,101	55,780
Diluted (in shares)	55,768	56,390	56,034	56,681
Subcontractor costs
Cost of revenue	$ (202,597)	$ (194,443)	$ (503,902)	$ (576,813)
Other costs of revenue
Cost of revenue	$ (505,209)	$ (460,758)	$ (1,448,803)	$ (1,352,827)