Commitments and Contingencies - Narrative (Details) ft² in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) ft² building	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Long-term Purchase Commitment [Line Items]
Number of buildings occupied | building	2
Rent expense under operating leases | $	$ 3.7	$ 1.8	$ 1.0
Lease One [Member]
Long-term Purchase Commitment [Line Items]
Rentable square feet	67
Renewal term of lease contract	5 years
Lease Two [Member]
Long-term Purchase Commitment [Line Items]
Rentable square feet	129
Renewal term of lease contract	10 years