Earnings Per Share - Schedule of Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Basic
Net income available to common shareholders	$ 21,431	$ 19,392	$ 29,380	$ 40,432
Less: income attributable to unvested stock-based compensation awards	(251)	(306)	(350)	(655)
Net earnings allocated to common shareholders	$ 21,180	$ 19,086	$ 29,030	$ 39,777
Weighted average shares outstanding, including unvested stock-based compensation awards (in shares)	14,910,300	15,262,216	14,934,028	15,287,783
Less: unvested stock-based compensation awards (in shares)	(228,344)	(242,506)	(233,576)	(247,983)
Weighted average shares outstanding - Basic (in shares)	14,681,956	15,019,710	14,700,452	15,039,800
Diluted
Net earnings allocated to common shareholders	$ 21,180	$ 19,086	$ 29,030	$ 39,777
Weighted average shares outstanding - Basic (in shares)	14,681,956	15,019,710	14,700,452	15,039,800
Plus: Incremental shares from assumed conversion of stock-based compensation awards (in shares)	32,892	66,235	44,107	71,292
Weighted average shares outstanding - Diluted (in shares)	14,714,848	15,085,945	14,744,559	15,111,092
Basic EPS (in dollars per share)	$ 1.44	$ 1.27	$ 1.97	$ 2.64
Diluted EPS (in dollars per share)	$ 1.44	$ 1.27	$ 1.97	$ 2.63