Commitments and Contingencies (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Bonus Accrual [Roll Forward]
Accrued Bonuses	$ 25,175	$ 19,128
Accrued Bonuses	0	25,175	$ 19,128
Operating Leases, Rent Expense	2,400	2,300	1,400
Restructuring Reserve [Roll Forward]
Purchase commitment payable in 2016	276,000
Accruals [Member]
Bonus Accrual [Roll Forward]
Bonus Expense	2,853	7,384
liability acquired [Member]
Bonus Accrual [Roll Forward]
Bonus Liability Acquired		4,082
Payments [Member]
Bonus Accrual [Roll Forward]
Payments	(28,028)	(5,419)
Employee Severance
Restructuring Reserve [Roll Forward]
Beginning balance	20,718	0
Accrual	6,023	33,991
Payments	(17,064)	(13,273)
Ending balance	$ 9,677	$ 20,718	$ 0