Income Taxes - Provisions for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Domestic	$ 13,390	$ (6,899)	$ 11,028
Foreign	37,381	25,561	65,132
Total current	50,771	18,662	76,160
Deferred:
Domestic	(213,200)	(8,617)	40,284
Foreign	(21,813)	8,715	(11,194)
Total deferred	(235,013)	98	29,090
Income Tax Expense (Benefit)	(184,242)	18,760	105,250
Cash taxes paid	$ 43,347	$ 75,819	$ 119,591