Summary of Significant Accounting Policies - Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ 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
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net (losses) earnings	$ 2,653	$ 640	$ 6	$ 4,908	$ (3,848)	$ 2,035	$ 3,620	$ 1,138	$ 8,207	$ 2,945	$ (482)
Basic weighted average number of shares outstanding (in shares)									4,228	4,218	4,218
Basic earnings (losses) per share (in dollars per share)	$ 0.63	$ 0.15	$ 0	$ 1.16	$ (0.91)	$ 0.48	$ 0.86	$ 0.27	$ 1.94	$ 0.70	$ (0.11)
Diluted weighted average number of shares outstanding (in shares)									4,233	4,218	4,218
Diluted earnings (losses) per share (in dollars per share)	$ 0.63	$ 0.15	$ 0	$ 1.16	$ (0.91)	$ 0.48	$ 0.86	$ 0.27	$ 1.94	$ 0.70	$ (0.11)
Restricted stock units awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units award (in shares)									5	0	0
Performance share unit awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units award (in shares)									0	0	0