Income Taxes - Schedule of Reconciliation of the Beginning and Ending Amount of Reserve for Uncertain Tax Positions(Excluding Interest and Penalties) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of reserve for uncertain tax positions, Excluding Amounts Pertaining to Examined Tax Returns
Beginning Balance	$ 252,434	$ 259,301	$ 56,957
Additions based on tax positions related to current year	50,469	23,978	152,983
Additions for tax positions of prior years	8,978	20,336	50,688
Reductions for tax positions of prior years	(10,323)	(51,181)	(1,327)
Lapse of statute of limitations	0	0	0
Ending Balance	$ 301,558	$ 252,434	$ 259,301