Net Income Per Share - Calculation of Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Numerator:
Net income	$ 95,894	$ 77,491	$ 81,800
Net income allocated to participating securities under the two-class method	0	(37)	(80)
Net income attributable to common stockholders—basic	95,894	77,454	81,720
Dilutive effect of net income allocated to participating securities under the two-class method	0	37	80
Change in fair value of liability classified restricted stock	0	0	771
Net income attributable to common stockholders—diluted	$ 95,894	$ 77,491	$ 82,571
Denominator:
Weighted average common shares outstanding—basic (in shares)	119,665,248	120,146,076	118,538,687
Weighted average common shares outstanding—diluted (in shares)	125,720,073	127,084,785	122,267,673
Net (loss) income per share attributable to common stockholders—basic (in shares)	$ 0.80	$ 0.64	$ 0.69
Net (loss) income per share attributable to common stockholders—diluted (in shares)	$ 0.76	$ 0.61	$ 0.68
Anti-dilutive securities excluded from computation of earnings per share (in shares)	10,535,628	612,236	5,338,022
Common Stock
Denominator:
Dilutive effect of assumed conversion (in shares)	4,516,413	4,238,622	2,498,448
Restricted stock units
Denominator:
Dilutive effect of assumed conversion (in shares)	1,521,719	1,721,658	1,177,799
Convertible senior notes
Denominator:
Dilutive effect of assumed conversion of convertible debt (2)	0	900,580	0
Restricted Stock
Denominator:
Dilutive effect of assumed conversion (in shares)	16,693	77,849	52,739
Participating Securities
Denominator:
Anti-dilutive securities excluded from computation of earnings per share (in shares)		57,482	114,963