Stockholders' Equity - Reconciliation of Weighted Average Shares (Details) - USD ($) $ 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
Net income:
Net income	$ 17,126	$ 17,895	$ 15,984	$ 16,552	$ 16,609	$ 15,504	$ 11,857	$ 9,087	$ 67,557	$ 53,057	$ 41,791
Dividends and undistributed earnings allocated to participating securities(1)									(57)	(223)	(293)
Net income allocated to common shareholders									$ 67,500	$ 52,834	$ 41,498
Basic:
Weighted average common shares outstanding (in shares)									36,789,244	35,281,408	29,937,400
Restricted stock awards (in shares)									(31,014)	(87,405)	(179,581)
Total basic weighted average common shares outstanding (in shares)									36,758,230	35,194,003	29,757,819
Diluted:
Basic weighted average common shares outstanding (in shares)									36,758,230	35,194,003	29,757,819
Effect of potentially dilutive common shares (in shares)									227,536	177,587	91,512
Total diluted weighted average common shares outstanding (in shares)									36,985,766	35,371,590	29,849,331