Earnings Per Share - Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Reconciliation of net income before minority interest to net income available for common stockholders
Income before income taxes and non-controlling interest	$ (46,495)	$ 37,874	$ (17,421)	$ 140,990
Provision for (benefit from) income taxes	(6,505)	4,851	(2,918)	17,325
Net income (loss)	(39,990)	33,023	(14,503)	123,665	$ 158,340
Noncontrolling interest	26,472	(25,997)	6,466	(97,913)
Net income available for common stockholders	$ (13,518)	$ 7,026	$ (8,037)	$ 25,752