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]	Class B [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 Dec. 31, 2018	$ 54,720	$ (7,347)	$ 308,075	$ 356,082	$ 112	$ 522
Beginning balance (in shares) at Dec. 31, 2018					2,615,000	12,254,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss (income)	0	0	4,283	4,283	$ 0	$ 0
Foreign currency translation adjustment, net of tax	0	591	0	591	0	0
Change in unrealized gain (loss) on investments, net of tax	0	14,973	0	14,973	0	0
Common stock dividends	0	0	(2,987)	(2,987)	0	0
Repurchase of common shares	(1,614)	0	(4,858)	(6,487)	$ 0	$ (15)
Repurchase of common shares (in shares)					(3,000)	(371,000)
Restricted stock grants	959	0	0	961	$ 0	$ 2
Restricted stock grants (in shares)					0	49,000
Ending balance at Jun. 30, 2019	54,065	8,217	304,513	367,416	$ 112	$ 509
Ending balance (in shares) at Jun. 30, 2019					2,612,000	11,932,000
Beginning balance at Mar. 31, 2019	55,049	1,416	308,971	366,070	$ 112	$ 522
Beginning balance (in shares) at Mar. 31, 2019					2,615,000	12,249,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss (income)	0	0	1,535	1,535	$ 0	$ 0
Foreign currency translation adjustment, net of tax	0	284	0	284	0	0
Change in unrealized gain (loss) on investments, net of tax	0	6,517	0	6,517	0	0
Common stock dividends	0	0	(1,494)	(1,494)	0	0
Repurchase of common shares	(1,506)	0	(4,499)	(6,020)	$ 0	$ (15)
Repurchase of common shares (in shares)					(3,000)	(346,000)
Restricted stock grants	522	0	0	524	$ 0	$ 2
Restricted stock grants (in shares)					0	29,000
Ending balance at Jun. 30, 2019	54,065	8,217	304,513	367,416	$ 112	$ 509
Ending balance (in shares) at Jun. 30, 2019					2,612,000	11,932,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of the adoption of updated accounting guidance for credit losses, net of tax | ASU 2016-13 [Member]								$ 0	$ 0	$ (12,281)	$ (12,281)	$ 0	$ 0
Beginning balance at Dec. 31, 2019	53,349	9,369	300,988	364,316	$ 111	$ 499
Beginning balance (ASU 2016-13 [Member]) at Dec. 31, 2019										$ (12,281)
Beginning balance (in shares) at Dec. 31, 2019					2,603,000	11,676,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss (income)	0	0	(10,789)	(10,789)	$ 0	$ 0
Foreign currency translation adjustment, net of tax	0	(466)	0	(466)	0	0
Change in unrealized gain (loss) on investments, net of tax	0	(1,010)	0	(1,010)	0	0
Common stock dividends	0	0	(2,858)	(2,858)	0	0
Repurchase of common shares	(563)	0	(1,214)	(1,782)	$ 0	$ (5)
Repurchase of common shares (in shares)					0	(127,000)	(126,764)
Restricted stock grants	906	0	0	908	$ 0	$ 2
Restricted stock grants (in shares)					0	61,000
Ending balance at Jun. 30, 2020	53,692	7,893	273,846	336,038	$ 111	$ 496
Ending balance (in shares) at Jun. 30, 2020					2,603,000	11,610,000
Beginning balance at Mar. 31, 2020	53,045	(12,179)	263,911	305,383	$ 111	$ 495
Beginning balance (in shares) at Mar. 31, 2020					2,603,000	11,580,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss (income)	0	0	11,367	11,367	$ 0	$ 0
Foreign currency translation adjustment, net of tax	0	221	0	221	0	0
Change in unrealized gain (loss) on investments, net of tax	0	19,851	0	19,851	0	0
Common stock dividends	0	0	(1,432)	(1,432)	0	0
Repurchase of common shares	0	0	0	0	$ 0	$ 0
Repurchase of common shares (in shares)					0	0
Restricted stock grants	647	0	0	648	$ 0	$ 1
Restricted stock grants (in shares)					0	30,000
Ending balance at Jun. 30, 2020	$ 53,692	$ 7,893	$ 273,846	$ 336,038	$ 111	$ 496
Ending balance (in shares) at Jun. 30, 2020					2,603,000	11,610,000