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
Earnings Per Share [Abstract]
Shares not included in computation of diluted weighted average earnings per common (in shares)									0	400
Net income attributable to common shareholders	$ 4,156	$ 23,232	$ 16,144	$ 20,056	$ 17,274	$ 8,834	$ 7,528	$ 6,261	$ 63,588	$ 39,898
Basic weighted average common shares outstanding (in shares)	5,850,000	5,847,000	5,866,000	5,779,000	5,782,000	5,900,000	5,878,000	6,104,000	5,836,000	5,915,000
Potentially dilutive common shares (in shares)									222,000	131,000
Diluted weighted average common shares outstanding (in shares)	6,099,000	6,094,000	6,061,000	5,978,000	5,939,000	6,004,000	5,991,000	6,256,000	6,058,000	6,046,000
Basic weighted average earnings per common share (in dollars per share)	$ 0.71	$ 3.97	$ 2.75	$ 3.47	$ 2.99	$ 1.50	$ 1.28	$ 1.03	$ 10.90	$ 6.75
Diluted weighted average earnings per common share (in dollars per share)	$ 0.68	$ 3.81	$ 2.66	$ 3.35	$ 2.91	$ 1.47	$ 1.26	$ 1.00	$ 10.50	$ 6.60