Commitments and Contingencies - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Rental expense for operating leases	$ 10,000,000	$ 9,900,000	$ 9,500,000
Defined benefit plan employer matching contribution on first five percent of employee compensation	50.00%
Percentage of employees' eligible compensation for employer matching contribution	5.00%
Defined benefit plan employer contribution limit per employee	$ 6,000
Defined benefit plan employer contribution vesting period	5 years
Compensation	$ 1,300,000	$ 1,300,000	$ 900,000