Earnings per Share - Schedule of Reconciliation of the Numerators and Denominators of the Basic and Diluted Net Income Per Share Computations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Net income available to common stockholders	$ 37,055	$ 37,704	$ 94,220	$ 95,355
Shares outstanding:
Weighted average shares outstanding – basic	77,721,353	77,522,664	77,657,553	77,445,611
Weighted average shares outstanding – diluted	78,449,747	78,283,588	78,588,517	78,208,040
Net income per common share attributable to common stockholders – basic:	$ 0.48	$ 0.49	$ 1.21	$ 1.23
Net income per common share attributable to common stockholders – diluted:	$ 0.47	$ 0.48	$ 1.20	$ 1.22
Stock Options
Shares outstanding:
Effect of dilutive securities	103,337	93,530	105,036	125,861
Restricted Stock Units (RSUs)
Shares outstanding:
Effect of dilutive securities	625,057	667,394	825,928	636,568