Earnings per Share (EPS) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Net income	$ 6,451	$ 14,090	$ 16,546	$ 31,251
Less: earnings attributable to unvested shares	(34)	(57)	(72)	(112)
Net income available to participating common shareholders	$ 6,417	$ 14,033	$ 16,474	$ 31,139
Weighted average number of participating common and potential common shares outstanding:
Basic number of participating common shares outstanding (in shares)	19,583,316	19,525,284	19,575,764	19,511,097
Dilutive effect of stock equivalents (in shares)	201,729	313,678	164,498	279,473
Diluted number of weighted average participating common shares outstanding (in shares)	19,785,045	19,838,962	19,740,262	19,790,570
Earnings per participating common share:
Earnings per participating common share - Basic (in dollars per share)	$ 0.33	$ 0.72	$ 0.84	$ 1.60
Earnings per participating common share - Diluted (in dollars per share)	$ 0.32	$ 0.71	$ 0.83	$ 1.57
Total outstanding options, performance share awards and unvested restricted stock not included in the calculation of diluted earnings per share as the effect would be anti-dilutive (in shares)	966,943	431,751	982,049	465,956