Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
General and administrative expense	$ 1,564	$ 2,275	$ 6,018	$ 7,835
Operating loss	(1,564)	(2,275)	(6,018)	(7,835)
Other income (loss), net	20,588	(820)	28,027	(7,045)
Interest income	70	52	197	209
Equity income (loss), net	(761)	(1,300)	13,432	(15,591)
Net income (loss) before income taxes	18,333	(4,343)	35,638	(30,262)
Net income (loss)	$ 18,333	$ (4,343)	$ 35,638	$ (30,262)
Net income (loss) per share:
Basic (in dollars per share)	$ 0.88	$ (0.21)	$ 1.71	$ (1.46)
Diluted (in dollars per share)	$ 0.88	$ (0.21)	$ 1.71	$ (1.46)
Weighted average shares used in computing income (loss) per share:
Basic (in shares)	20,786	20,786	20,847	20,731
Diluted (in shares)	20,786	20,786	20,847	20,731