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]
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	2,748	2,748	$ 0	$ 0
Foreign currency translation adjustment, net of tax	0	307	0	307	0	0
Change in unrealized gain (loss) on investments, net of tax	0	8,456	0	8,456	0	0
Common stock dividends	0	0	(1,493)	(1,493)	0	0
Repurchase of common stock	(108)	0	(359)	(468)	$ 0	$ (1)
Repurchase of common stock (in shares)					0	(25,000)
Restricted stock grants	437	0	0	438	$ 0	$ 1
Restricted stock grants (in shares)					0	20,000
Ending balance at Mar. 31, 2019	55,049	1,416	308,971	366,070	$ 112	$ 522
Ending balance (in shares) at Mar. 31, 2019					2,615,000	12,249,000
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 (in shares) at Dec. 31, 2019					2,603,000	11,676,000
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 gain (loss) 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 stock	(563)	0	(1,214)	(1,782)	$ 0	$ (5)
Repurchase of common stock (in shares)					0	(127,000)	(126,764)
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