Debt, Commitments and Contingencies - Leases (Details) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Aug. 31, 2014 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($) ft²
Leases, Operating [Abstract]
Lease renewal term	5 years
Available leasehold improvement allowance	$ 8.0	$ 9.7		$ 9.7
Square footage of additional office space | ft²						30,662
Additional leasehold improvement allowance						$ 1.7
Rent expense		$ 1.6	$ 1.2	$ 2.9	$ 2.5