Summary of Significant Accounting Policies - Schedule of Reconciliation of Denominators and Additional Shares that are Excluded from the Calculation of EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Weighted-average shares:
Basic weighted-average common shares outstanding									35,881	35,547	39,056
Total weighted-average shares									35,981	35,689	39,146
Earnings per common share—Basic
Net income	$ 29,813	$ 23,977	$ 27,455	$ 19,198	$ 22,761	$ 19,305	$ 16,568	$ 14,551	$ 100,443	$ 73,185	$ 39,122
Net income available to common shareholders—Basic									$ 100,164	$ 72,894	$ 39,032
Net income per common share—Basic	$ 0.82	$ 0.67	$ 0.76	$ 0.54	$ 0.64	$ 0.54	$ 0.46	$ 0.41	$ 2.79	$ 2.05	$ 1.00
Basic weighted-average common shares outstanding									35,881	35,547	39,056
Effect of diluted shares									1,695	1,365	783
Diluted weighted-average shares outstanding									37,576	36,912	39,839
Net income per common share—Diluted	$ 0.78	$ 0.63	$ 0.73	$ 0.51	$ 0.61	$ 0.52	$ 0.45	$ 0.40	$ 2.67	$ 1.97	$ 0.98
RSAs
Weighted-average shares:
Basic weighted-average common shares outstanding									100	142	90
Earnings per common share—Basic
Less: Undistributed earnings allocated to RSAs									$ 279	$ 291	$ 90
Basic weighted-average common shares outstanding									100	142	90
Common Stock
Weighted-average shares:
Basic weighted-average common shares outstanding									35,881	35,547	39,056
Earnings per common share—Basic
Basic weighted-average common shares outstanding									35,881	35,547	39,056