CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (20,745)	$ 4,659	$ (40,091)	$ 7,904
Change in net unrealized gains (losses) on investments, available-for-sale, net of tax	1,373	2,388	5,482	15,398
Comprehensive income (loss)	$ (19,372)	$ 7,047	$ (34,609)	$ 23,302