Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	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, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share
Net income, Basic													$ 84,369	$ 56,239	$ 42,958
Basic common shares outstanding													44,639,430	44,617,361	42,092,361
Earnings per share, Basic	$ 0.50	$ 0.69	$ 0.40	$ 0.30	$ 0.34	$ 0.39	$ 0.28	$ 0.25	$ 0.32	$ 0.33	$ 0.13	$ 0.23	$ 1.89	$ 1.26	$ 1.02
Net income, Diluted													$ 84,369	$ 56,239	$ 42,958
Effect of options, restricted stock and contingent shares issuable													261,375	293,904	474,747
Diluted common shares outstanding													44,900,805	44,911,265	42,567,108
Earnings per share, Diluted	$ 0.50	$ 0.69	$ 0.40	$ 0.29	$ 0.34	$ 0.39	$ 0.28	$ 0.25	$ 0.31	$ 0.33	$ 0.12	$ 0.23	$ 1.88	$ 1.25	$ 1.01