Commitments and Contingencies - Lease Commitments (Details)	12 Months Ended
	Dec. 31, 2015 USD ($) ft²	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Commitments and Contingencies
Lease agreement square footage | ft²	18,500
Rent expense	$ 628,000	$ 277,000	$ 214,000
Future minimum lease payments under non-cancelable facility operating leases
2016	650,000
2017	650,000
2018	660,000
2019	666,000
2020	223,000
Total	$ 2,849,000