Income Taxes - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Tax at federal statutory rate									$ (54,170)	$ (95,414)	$ (114,100)
State taxes, net of federal effect									191	25	42
Impact on noncontrolling interest									3,725	6,347	19,264
Non-U.S. tax effect									960	(437)	54
Nondeductible expenses									6,637	5,698	4,426
Stock-based compensation									3,892	4,854	4,243
U.S. tax reform impact									0	239,117	0
U.S. tax on foreign earnings									127	0	0
Change in valuation allowance									40,175	(159,554)	86,800
Provision for income taxes	$ 1,079	$ (3)	$ 128	$ 333	$ (120)	$ 314	$ 228	$ 214	$ 1,537	$ 636	$ 729