CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income (loss):	$ 59,236	$ 15,464	$ (1,971)
Available-for-sale investment items:
Reclassification of net realized gain included in earnings	(10,750)	(795)	(5,311)
Reclassification of other-than-temporary impairment loss included in earnings	2,288	0	0
Total before income taxes	(6,456)	5,196	339
Income tax benefit (expense)	2,488	(2,003)	300
Total other comprehensive (loss) income, net of tax	(3,968)	3,193	639
Total comprehensive income (loss), net of tax	55,268	18,657	(1,332)
Available-for-sale securities
Available-for-sale investment items:
Net unrealized gain on available-for-sale investments	2,015	5,997	5,650
Restricted investments
Available-for-sale investment items:
Net unrealized gain on available-for-sale investments	$ (9)	$ (6)	$ 0