Accounting Policies - Schedule of Earnings Per Share (Details) - USD ($) $ / shares in Units, $ 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
Accounting Policies [Abstract]
Income	$ 20,471	$ (25,167)	$ 20,307	$ 22,728	$ 11,632	$ 19,581	$ 16,984	$ 15,633	$ 38,339	$ 63,830	$ 43,566
Weighted average common shares
Basic (in shares)									30,275,184	29,887,990	29,461,717
Common share equivalents (in shares)									398,740	419,111	811,432
Diluted (in shares)									30,673,924	30,307,101	30,273,149
Earnings per share
Basic earnings per share (in dollars per share)	$ 0.67	$ (0.83)	$ 0.67	$ 0.76	$ 0.39	$ 0.65	$ 0.57	$ 0.53	$ 1.27	$ 2.14	$ 1.48
Common share equivalents (in dollars per share)									(0.02)	(0.03)	(0.04)
Diluted earnings per share (in dollars per share)	$ 0.67	$ (0.83)	$ 0.66	$ 0.75	$ 0.38	$ 0.64	$ 0.56	$ 0.52	$ 1.25	$ 2.11	$ 1.44