Commitments and Contingencies Commitments and Contingencies Details 1 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$ 2,143	$ 1,951	$ 1,163
Purchase Obligation, Future Minimum Payments, Remainder of Fiscal Year	466,693
Purchase Obligation, Due in Second Year	470,073
Purchase Obligation, Due in Third Year	375,216
Purchase Obligation, Due in Fourth Year	141,643
Purchase Obligation, Due in Fifth Year	0
Purchase Obligation, Due after Fifth Year	0
Purchase Obligation	$ 1,453,625