Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
AOCI Attributable to Parent, Net of Tax
Beginning balance	$ 932,264	$ 459,953	$ 172,408
Other comprehensive income (loss) before reclassifications	261	(4)	(191)
Reclassification adjustment for gains (losses) included in net income (loss)	106	(584)	65
Ending balance	934,389	932,264	459,953
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax
Beginning balance	(4,205)	(3,617)	(3,491)
Ending balance	$ (3,838)	$ (4,205)	$ (3,617)