CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (2,483)	$ 32,779	$ 135,817
Unrealized gains (losses) on securities:
Holding gains (losses) arising during period, net of tax	261	(4)	(191)
Reclassification adjustment for gains (losses) included in net income (loss), net of tax	106	(584)	65
Net unrealized gains (losses) on securities	367	(588)	(126)
Total comprehensive income (loss)	$ (2,116)	$ 32,191	$ 135,691