CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 3,403	$ 12,037	$ (16,832)	$ 9,523
Other comprehensive income (loss), net of tax:
Change in unrealized gains/losses on available-for-sale securities, net of tax	(11)	(79)	11	569
Change in unrealized gains/losses on derivative contracts, net of tax	(2,689)	1,717	2,053	3,066
Other comprehensive income (loss), net of tax	(2,700)	1,638	2,064	3,635
Total comprehensive income (loss), net of tax	$ 703	$ 13,675	$ (14,768)	$ 13,158