Commitments and Contingencies - Additional Information (Details) £ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017 USD ($) $ / £	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) $ / £	Sep. 30, 2016 USD ($)	Sep. 30, 2017 GBP (£) $ / £	Dec. 31, 2016 USD ($)
Commitments And Contingencies [Line Items]
Purchase Commitments	$ 36,800,000		$ 36,800,000
Foreign currency hedges amount	40,200,000		$ 40,200,000
Foreign currency exposure, description			At September 30, 2017 the Company had approximately $40.2 million in foreign currency hedges, which are intended to offset approximately 25% of the Company's estimated foreign currency exposure
Percentage of estimated foreign currency exposure offset by foreign currency hedges			25.00%
Income contributed from foreign currency hedges	500,000		$ 500,000
Interest expense	3,561,000	$ 3,684,000	10,493,000	$ 9,880,000
Designated as Hedging Instrument | Cash Flow Hedges | Interest Rate Swaps
Commitments And Contingencies [Line Items]
Interest rate derivative agreements, notional amount	220,000,000		220,000,000			$ 150,000,000
Derivative asset from notional amount accounted for effective cash flow hedge	2,400,000		2,400,000			3,100,000
Amount accrued on accumulated other comprehensive income from notional amount accounted for effective cash flow hedge	2,400,000		2,400,000			$ 2,300,000
Interest expense	200,000		$ 600,000
Pension Plan, Defined Benefit
Commitments And Contingencies [Line Items]
Defined benefit plan, estimated future employer contributions in current fiscal year, description			We have a contributory defined benefit plan that covers certain employees in the United Kingdom. As of September 30, 2017, the unfunded liability for this defined benefit plan was approximately $32.3 million. We are obligated to make annual contributions, each year through December 2029, of approximately GBP 2 million (approximately $2.6 million based on a GBP:USD exchange rate of 1.3). The trustees are required to review the funding position every three years, and the most recent review was carried out as of April 5, 2016. The outcome of a review can result in a change in the amount of the payment.
Defined benefit plan, expected future benefit payments in year one	2,600,000		$ 2,600,000		£ 2
Defined benefit plan, expected future benefit payments in year two	2,600,000		2,600,000		2
Defined benefit plan, expected future benefit payments in year three	2,600,000		2,600,000		2
Defined benefit plan, expected future benefit payments in year four	2,600,000		2,600,000		2
Defined benefit plan, expected future benefit payments in year five	2,600,000		2,600,000		2
Defined benefit plan, expected future benefit payments in eight fiscal years thereafter	$ 2,600,000		$ 2,600,000		£ 2
GBP:USD exchange rate | $ / £	1.3		1.3		1.3
Unfunded liability of defined benefit plan	$ 32,300,000		$ 32,300,000