Commitments and Contingencies - Lease Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$ 2,700	$ 1,800	$ 7,000	$ 5,300
Deferred rent credit	8,800		8,800		$ 400
Operating Leased Assets]
Total lease commitment	48,167		$ 48,167
Not yet received tenant allowance recorded in other assets, accrued liabilities and other non-current liabilities				$ 0
Headquarter Office Facility
Operating Leased Assets]
Lease term (in years)			10 years
Total lease commitment	$ 38,600		$ 38,600
Not yet received tenant allowance recorded in other assets, accrued liabilities and other non-current liabilities			$ 8,076