401(k) Plan (Details) - 401(k) Benefit Plan [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Employer matching contribution, percent	50.00%
Company contributions to benefit plan	$ 1.8	$ 1.6	$ 0.9