CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (21,479)	$ 7,110	$ (19,346)	$ 3,245
Change in net unrealized gains (losses) on investments, available-for-sale, net of tax	8,137	6,122	4,109	13,010
Comprehensive income (loss)	$ (13,342)	$ 13,232	$ (15,237)	$ 16,255