Earnings per Common Share - Details of Earnings Per Share Calculations (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings per Common Share
Net income (loss)	$ (1,756)	$ (1,678)	$ (2,023)	$ 4	$ 4,585	$ 11,847	$ (2,511)	$ (6,056)	$ (5,455)	$ 7,864	$ 3,044
Weighted average common shares outstanding:
Basic									40,035	40,050	39,932
Incremental shares with dilutive effect:
Restricted stock awards (in shares)										86	114
Diluted (in shares)									40,035	40,136	40,046
Basic	$ (0.04)	$ (0.04)	$ (0.05)	$ 0.00	$ 0.11	$ 0.30	$ (0.06)	$ (0.15)	$ (0.14)	$ 0.20	$ 0.08
Diluted	$ (0.04)	$ (0.04)	$ (0.05)	$ 0.00	$ 0.11	$ 0.30	$ (0.06)	$ (0.15)	$ (0.14)	$ 0.20	$ 0.08