Net Income Per Share - Reconciliation of Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net Income
Net income available to common stockholders	$ 36,210	$ 36,757	$ 103,465	$ 116,630
Diluted net income per share	$ 36,210	$ 36,757	$ 103,465	$ 116,630
Weighted-Average Shares
Net income available to common stockholders (in shares)	53,843,508	51,433,227	54,111,848	50,085,701
Effect of potentially dilutive stock options and restricted stock awards (in shares)	127,090	136,330	166,034	141,679
Diluted net income per share (in shares)	53,970,598	51,569,557	54,277,882	50,227,380
Per Share Amount
Net income available to common stockholders (in dollars per share)	$ 0.67	$ 0.71	$ 1.91	$ 2.33
Diluted net income per share (in dollars per share)	$ 0.67	$ 0.71	$ 1.91	$ 2.32