Consolidated Statements of Equity - USD ($) $ in Thousands	Cumulative Effect, Period of Adoption, Adjustment [Member] Common Stock [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Additional Paid-in Capital [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Retained Earnings [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Parent [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Noncontrolling Interest [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Parent [Member]	Noncontrolling Interest [Member]	Total
Balance (in shares) at Dec. 31, 2017							20,876,837
Balance at Dec. 31, 2017	$ 0	$ (18)	$ (3,347)	$ (3,365)	$ 0	$ (3,365)	$ 209	$ 199,474	$ 64,307	$ 263,990	$ 90	$ 264,080
Net loss							0	0	(14,216)	(14,216)	(14)	(14,230)
Stock-based compensation expense							$ 0	3,090	0	3,090	0	3,090
Shares net settled with the Company to satisfy employee personal income tax liabilities resulting from share based compensation plans (in shares)							(86,692)
Shares net settled with the Company to satisfy employee personal income tax liabilities resulting from share based compensation plans							$ 0	(982)	0	(982)	0	(982)
Shares issued through stock plans (in shares)							271,875
Shares issued through stock plans							$ 2	(2)	0	0	0	$ 0
Repurchase of common stock (in shares)							(1,003,116)					(1,003,116)
Repurchase of common stock							$ (10)	(8,430)	(123)	(8,563)	0	$ (8,563)
Balance (in shares) at Dec. 31, 2018							20,058,904
Balance at Dec. 31, 2018							$ 201	193,132	46,621	239,954	76	240,030
Net loss							0	0	(8,037)	(8,037)	36	(8,001)
Stock-based compensation expense							$ 0	2,260	0	2,260	0	2,260
Shares net settled with the Company to satisfy employee personal income tax liabilities resulting from share based compensation plans (in shares)							(85,420)
Shares net settled with the Company to satisfy employee personal income tax liabilities resulting from share based compensation plans							$ 0	(488)	0	(488)	0	(488)
Shares issued through stock plans (in shares)							277,401
Shares issued through stock plans							$ 2	(2)	0	0	0	$ 0
Repurchase of common stock (in shares)							(153,916)					(153,916)
Repurchase of common stock							$ (2)	(1,040)	0	(1,042)	0	$ (1,042)
Balance (in shares) at Dec. 31, 2019							20,096,969					20,096,969
Balance at Dec. 31, 2019							$ 201	193,862	38,584	232,647	112	$ 232,759
Net loss							0	0	(32,819)	(32,819)	(50)	(32,869)
Stock-based compensation expense							$ 0	2,197	0	2,197	0	2,197
Shares net settled with the Company to satisfy employee personal income tax liabilities resulting from share based compensation plans (in shares)							(58,644)
Shares net settled with the Company to satisfy employee personal income tax liabilities resulting from share based compensation plans							$ 0	(304)	0	(304)	0	(304)
Shares issued through stock plans (in shares)							244,812
Shares issued through stock plans							$ 2	(2)	0	0	0	$ 0
Repurchase of common stock (in shares)							(2,160,792)					(2,160,792)
Repurchase of common stock							$ (22)	(4,257)	0	(4,279)	0	$ (4,279)
Non-controlling interest distribution							$ 0	0	0	0	(62)	$ (62)
Balance (in shares) at Dec. 31, 2020							18,122,345					18,122,345
Balance at Dec. 31, 2020							$ 181	$ 191,496	$ 5,765	$ 197,442	$ 0	$ 197,442