Employee 401 (k) Plan - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Employer matching contributions, vesting schedule	5 years
Employer 401(k) contributions		$ 407	$ 4,000
Profit Sharing Plan
Defined Benefit Plan Disclosure [Line Items]
Employer matching contributions, vesting schedule	5 years