Summary of Significant Accounting Policies - Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Income Taxes
Income tax expense (benefit)	$ 38			$ 0	$ (109,959)	$ 0
Reversal of valuation allowance included in income tax benefit					117,200
Reversal of Valuation Allowance
Net deferred tax assets	117,200				117,200		$ 124,500
Valuation allowance for deferred tax assets	6,700				6,700		$ 124,500
Decrease in deferred tax asset valuation allowance	$ 4,300	$ 112,900	$ 600		117,800
Taxes paid					$ 800	$ 0