Unaudited Condensed Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Total	Class A [Member] Common Stock [Member]	Class B [Member] Common Stock [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Additional Paid-in Capital [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Accumulated Other Comprehensive Income (Loss) [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Retained Earnings [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Class A [Member] Common Stock [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Class B [Member] Common Stock [Member]
Beginning balance at December 31, 2020 at Dec. 31, 2019	$ 53,349	$ 9,369	$ 300,988	$ 364,316	$ 111	$ 499
Beginning balance at December 31, 2020 (ASU 2016-13 [Member]) at Dec. 31, 2019							$ 0	$ 0	$ (12,281)	$ (12,281)	$ 0	$ 0
Beginning balance (in shares) at Dec. 31, 2019					2,603,000	11,676,000
Beginning balance (in shares) (ASU 2016-13 [Member]) at Dec. 31, 2019											0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss (income)	0	0	(22,156)	(22,156)	$ 0	$ 0
Foreign currency translation adjustment, net of tax	0	(687)	0	(687)	0	0
Change in unrealized gains (losses) on investments, net of tax	0	(20,861)	0	(20,861)	0	0
Common stock dividends	0	0	(1,426)	(1,426)	0	0
Repurchase of common shares	(563)	0	(1,214)	(1,782)	$ 0	$ (5)
Repurchase of common shares (in shares)					0	(127,000)
Restricted stock grants	259	0	0	260	$ 0	$ 1
Restricted stock grants (in shares)					0	31,000
Ending balance at Mar. 31, 2020	53,045	(12,179)	263,911	305,383	$ 111	$ 495
Ending balance (in shares) at Mar. 31, 2020					2,603,000	11,580,000
Beginning balance at December 31, 2020 at Dec. 31, 2020	54,571	21,759	286,143	363,082	$ 111	$ 498
Beginning balance (in shares) at Dec. 31, 2020					2,603,000	11,675,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss (income)			12,938	12,938
Foreign currency translation adjustment, net of tax		88		88
Change in unrealized gains (losses) on investments, net of tax		(9,081)		(9,081)
Common stock dividends			(1,424)	$ (1,424)
Repurchase of common shares (in shares)				0
Restricted stock grants	1,074			$ 1,075		$ 1
Restricted stock grants (in shares)						30,000
Ending balance at Mar. 31, 2021	$ 55,645	$ 12,766	$ 297,657	$ 366,678	$ 111	$ 499
Ending balance (in shares) at Mar. 31, 2021					2,603,000	11,705,000