Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Numerator for basic and diluted net income per share:
Net income from continuing operations	$ 40,545	$ 22,535	$ 36,754	$ 109,429
Loss from discontinued operations, net of tax	(17,362)	(84)	(17,456)	(175)
Net income	$ 23,183	$ 22,451	$ 19,298	$ 109,254
Denominator:
Weighted-average shares for basic income per share (in shares)	79,761	80,680	80,138	81,073
Dilutive effect of stock options and restricted stock units (in shares)	1,153	1,337	1,067	1,455
Weighted-average shares for diluted income per share (in shares)	80,914	82,017	81,205	82,528
Basic:
Net (loss)/income from continuing operations (usd per share)	$ 0.51	$ 0.28	$ 0.46	$ 1.35
Loss from discontinued operations, net of tax (usd per share)	(0.22)	0	(0.22)	0
Net (loss)/income (usd per share)	0.29	0.28	0.24	1.35
Diluted:
Net income from continuing operations (usd per share)	0.50	0.27	0.45	1.33
Loss from discontinued operations, net of tax (usd per share)	(0.21)	0	(0.21)	0
Net (loss)/income (usd per share)	$ 0.29	$ 0.27	$ 0.24	$ 1.33
RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	100	100	100	100
PBRSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share			100	100