Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Consolidated Statements of Operations [Abstract]
General and administrative expenses	$ (1,729)	$ (1,648)
Operating income (loss)	(1,729)	(1,648)
Interest and investment income	2	937
Interest expense	(6)	(5)
Other expense	(2,375)	(1,437)
Income (loss) before income taxes and equity in net income (loss) of affiliates	(4,108)	(2,153)
Income tax (provision) benefit	222	(2,116)
Income (loss) before equity in net income (loss) of affiliates	(3,886)	(4,269)
Equity in net income (loss) of affiliates	34,602	(117,074)
Net income (loss)	30,716	(121,343)
Other comprehensive income (loss), net of tax	(1,816)	31,290
Comprehensive income (loss)	$ 28,900	$ (90,053)
Net income per share:
Basic	$ 0.99	$ (3.92)
Diluted	$ 0.98	$ (3.92)
Weighted average common shares outstanding:
Basic	30,933	30,933
Diluted	31,032	30,933