Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Other Comprehensive Income (Loss), Unrealized gain (loss) on equity securities, tax	$ (767)	$ 0	$ 1,446
Other Comprehensive Income (Loss), Reclassification adjustments for impairment of equity securities, tax	0	0	(2,552)
Other Comprehensive Income (Loss), Reclassification adjustments for realized loss on sale of equity securities, tax	$ 0	$ 0	$ (219)