UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Contributed Capital	Retained Earnings
Beginning balance at Dec. 31, 2019	$ 151,641	$ 423	$ 12,778	$ 138,440
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (losses)	(11,427)			(11,427)
Stock-based compensation expense	134		134
Dividends declared:
Common stock	(1,016)			(1,016)
Awards under LTIP	(6)			(6)
Ending balance at Mar. 31, 2020	139,326	423	12,912	125,991
Beginning balance at Dec. 31, 2019	151,641	423	12,778	138,440
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (losses)	(4,851)
Ending balance at Sep. 30, 2020	144,084	423	13,150	130,511
Beginning balance at Mar. 31, 2020	139,326	423	12,912	125,991
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (losses)	3,503			3,503
Stock-based compensation expense	170		170
Cancellation of shares withheld to cover taxes upon vesting of restricted awards	(81)		(81)
Dividends declared:
Common stock	(1,018)			(1,018)
Awards under LTIP	(10)			(10)
Ending balance at Jun. 30, 2020	141,890	423	13,001	128,466
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (losses)	3,073			3,073
Stock-based compensation expense	149		149
Dividends declared:
Common stock	(1,018)			(1,018)
Awards under LTIP	(10)			(10)
Ending balance at Sep. 30, 2020	144,084	423	13,150	130,511
Beginning balance at Dec. 31, 2020	149,092	423	13,340	135,329
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (losses)	2,808			2,808
Stock-based compensation expense	185		185
Cancellation of shares withheld to cover taxes upon vesting of restricted awards	(31)		(31)
Dividends declared:
Common stock	(1,019)			(1,019)
Awards under LTIP	(18)			(18)
Ending balance at Mar. 31, 2021	151,017	423	13,494	137,100
Beginning balance at Dec. 31, 2020	149,092	423	13,340	135,329
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (losses)	9,063
Ending balance at Sep. 30, 2021	158,082	432	16,375	141,275
Beginning balance at Mar. 31, 2021	151,017	423	13,494	137,100
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (losses)	4,709			4,709
Stock-based compensation expense	232		232
Vesting of restricted awards	0	1	(1)
Cancellation of shares withheld to cover taxes upon vesting of restricted awards	(70)		(70)
Dividends declared:
Common stock	(1,021)			(1,021)
Awards under LTIP	(16)			(16)
Ending balance at Jun. 30, 2021	154,851	424	13,655	140,772
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (losses)	1,546			1,546
Stock-based compensation expense	224		224
Shares sold under at-the-market offering program	2,504	8	2,496
Dividends declared:
Common stock	(1,027)			(1,027)
Awards under LTIP	(16)			(16)
Ending balance at Sep. 30, 2021	$ 158,082	$ 432	$ 16,375	$ 141,275