Commitments and Contingencies - Operating Leases - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Leases [Abstract]
Rent expense, including other facility expenses	$ 8,593	$ 8,610	$ 8,511
Rental income under sublease agreement	1,051	$ 1,486	$ 908
Expected future rental income under sublease agreement, 2017	114
Expected future rental income under sublease agreement, 2018	80
Expected future rental income under sublease agreement, 2019	$ 67