Summary of Significant Accounting Policies - Reconciliation of Basic and Diluted Earnings (Losses) per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Basic earnings per share:
Net earnings	$ 6,090	$ 2,808
Basic weighted average number of shares outstanding (in shares)	4,359	4,246
Basic earnings (losses) per share (in dollars per share)	$ 1.40	$ 0.66
Diluted weighted average number of shares outstanding:
Common shares (in shares)	4,359	4,246
Total diluted shares (in shares)	4,394	4,271
Diluted earnings (losses) per share (in dollars per share)	$ 1.39	$ 0.66
Restricted stock units awards
Diluted weighted average number of shares outstanding:
Unit awards (in shares)	24	18
Performance share unit awards
Diluted weighted average number of shares outstanding:
Unit awards (in shares)	11	7