401(k) Plan - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Company matching contributions to maximum employees eligible compensation for every dollar contributed by employee	$ 0.50
Company contributions to 401 (k) plan	$ 5,100,000	$ 4,600,000	$ 3,500,000