Employee Benefit Plans - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Employee Benefit Plan [Line Items]
Defined benefit plan contributions by employer	$ 2,700	$ 2,600	$ 1,700
Global Equities
Employee Benefit Plan [Line Items]
Defined benefit plan, target plan asset allocations	60.00%
Global Bonds
Employee Benefit Plan [Line Items]
Defined benefit plan, target plan asset allocations	18.00%
Alternative Assets
Employee Benefit Plan [Line Items]
Defined benefit plan, target plan asset allocations	9.00%
Cash
Employee Benefit Plan [Line Items]
Defined benefit plan, target plan asset allocations	13.00%
UNITED KINGDOM
Employee Benefit Plan [Line Items]
Funding valuation period	3 years
Defined benefit plan contributions by employer	$ 955	$ 1,000
Defined benefit plan estimated employer contributions for 2014	$ 1,000
Defined benefit plans increase future employer contributions percentage	2.90%