Earnings per Share ("EPS") (Tables)

9 Months Ended

Jul. 01, 2018

Earnings Per Share [Abstract]

Schedule of number of weighted-average shares used to compute basic and diluted EPS

The following table sets forth the number of weighted-average shares used to compute basic and diluted EPS:

	Three Months Ended				Nine Months Ended
	July 1, 2018		July 2, 2017		July 1, 2018		July 2, 2017
	(in thousands, except per share data)
Net income attributable to Tetra Tech	$	33,322	$	29,983	$	108,082	$	83,407
Weighted-average common shares outstanding – basic	55,537		57,184		55,780		57,108
Effect of dilutive stock options and unvested restricted stock	853		977		901		1,008
Weighted-average common stock outstanding – diluted	56,390		58,161		56,681		58,116
Earnings per share attributable to Tetra Tech:
Basic	$	0.60	$	0.52	$	1.94	$	1.46
Diluted	$	0.59	$	0.52	$	1.91	$	1.44