Consolidated Statements of Stockholder's Equity Statement - USD ($) $ in Thousands	Total	Accumulated deficit [Member]	Accumulated other comprehensive income [Member]	Treasury stock [Member]	Common Stock Class A [Member] Common stock [Member]	Common Stock Class B [Member] Common stock [Member]
Balance at Dec. 31, 2020	$ 300,945	$ (82,352)	$ 128,255	$ (11,011)	$ 262,869	$ 3,184
Net income (loss)	(3,573)	(3,573)	0	0	0	0
Unrealized investment gains (losses), net	(56,518)	0	(56,518)	0	0	0
Comprehensive income (loss)	(60,091)	(3,573)	(56,518)	0	0	0
Stock-based compensation	(14)	0	0	0	(14)	0
Balance at Mar. 31, 2021	240,840	(85,925)	71,737	(11,011)	262,855	3,184
Balance at Dec. 31, 2021	320,571	(45,565)	117,492	(20,101)	265,561	3,184
Net income (loss)	(1,333)	(1,333)	0	0	0	0
Unrealized investment gains (losses), net	(124,217)	0	(124,217)	0	0	0
Comprehensive income (loss)	(125,550)	(1,333)	(124,217)	0	0	0
Common stock issuance	1,788	0	0	0	1,788	0
Stock-based compensation	93	0	0	0	93	0
Balance at Mar. 31, 2022	$ 196,902	$ (46,898)	$ (6,725)	$ (20,101)	$ 267,442	$ 3,184