Net Income Per Share - Reconciliation of Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net Income
Net income available to common stockholders	$ 55,559	$ 32,992	$ 105,028	$ 67,255
Diluted net income per share	$ 55,559	$ 32,992	$ 105,028	$ 67,255
Weighted-Average Shares
Net income available to common stockholders (in shares)	53,956,296	53,762,913	53,943,248	54,247,493
Effect of potentially dilutive stock options and restricted stock awards (in shares)	228,128	179,654	216,084	182,026
Diluted net income per share (in shares)	54,184,424	53,942,567	54,159,332	54,429,519
Per Share Amount
Net income available to common stockholders (in dollars per share)	$ 1.03	$ 0.62	$ 1.95	$ 1.24
Diluted net income per share (in dollars per share)	$ 1.03	$ 0.62	$ 1.94	$ 1.24