Derivative Financial Instruments - Additional Information (Details) € in Millions		1 Months Ended			3 Months Ended		9 Months Ended
	Feb. 15, 2017 USD ($)	Apr. 30, 2017 EUR (€) installment	Feb. 28, 2017 USD ($)	Dec. 31, 2016 USD ($) installment	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) item	Sep. 30, 2016 USD ($)	Dec. 31, 2016 EUR (€)
Derivative [Line Items]
Foreign currency unrealized gains expected to be reclassified into earnings over next twelve months					$ 1,700,000		$ 1,700,000
3.95% senior unsecured notes due 2027
Derivative [Line Items]
Proceeds from issue of senior notes in settlement of derivatives	$ 10,000,000
Swaps maturing September 2019
Derivative [Line Items]
Average fixed interest rate (as a percent)					1.087%		1.087%
Interest Rate Swap Agreements
Derivative [Line Items]
Derivative fixed interest rate (as a percent)		0.59%		0.365%					0.365%
Number of annual installments of swap amortization | installment		6		7
Beginning date of swap amortization		Jun. 30, 2019		Jun. 30, 2017
Final maturity date of swap amortization		Jun. 30, 2024		Jun. 30, 2023
Carrying value / fair value of derivative liabilities included in other liabilities				$ 100,000	$ 400,000		$ 400,000
Interest Rate Swap Agreements | U.S. dollars
Derivative [Line Items]
Variable Rate Basis							LIBOR
Interest Rate Swap Agreements | EUR
Derivative [Line Items]
Variable Rate Basis		EURIBOR		EURIBOR
Treasury Lock | Interest Lock Agreement
Derivative [Line Items]
Notional amount			$ 100,000,000			$ 150,000,000		$ 150,000,000
Derivative agreement date							Sep. 30, 2016
Derivative agreement second date							Feb. 28, 2017
Treasury Lock | Interest Lock Agreement | 3.95% senior unsecured notes due 2027
Derivative [Line Items]
Percentage of reduction in interest rate on senior notes			0.25%				0.25%
Foreign Currency Forward Exchange Contracts
Derivative [Line Items]
Number of credit contingency features | item							0
Foreign Currency Forward Exchange Contracts | Cash Flow Hedging
Derivative [Line Items]
Gains (losses) in other comprehensive income, effective portion					9,700,000	(1,400,000)	$ 31,700,000	(10,700,000)
Designated as Hedging Instrument | Swaps maturing September 2019
Derivative [Line Items]
Floating rate obligation					50,000,000		50,000,000
Designated as Hedging Instrument | Interest Rate Swap Agreements
Derivative [Line Items]
Floating rate obligation | €		€ 35.0							€ 25.0
Carrying value / fair value of derivative assets included in other assets				$ 700,000	600,000		600,000
Designated as Hedging Instrument | Foreign Currency Forward Exchange Contracts
Derivative [Line Items]
Carrying value / fair value of derivative assets included in other assets					13,500,000		13,500,000
Carrying value / fair value of derivative liabilities included in other liabilities				33,900,000	4,300,000		4,300,000
Notional amount				423,800,000	317,600,000		317,600,000
Designated as Hedging Instrument | Foreign Currency Forward Exchange Contracts | Cash Flow Hedging
Derivative [Line Items]
Net gain (loss) recognized in gross margin					(600,000)	(5,000,000)	(11,400,000)	(13,500,000)
Not Designated as Hedging Instrument | Foreign Currency Forward Exchange Contracts
Derivative [Line Items]
Carrying value / fair value of derivative assets included in other assets				1,000,000	100,000		100,000
Carrying value / fair value of derivative liabilities included in other liabilities				$ 300,000	1,600,000		1,600,000
Net gains on derivative contracts not designated as hedges					$ 4,000,000	$ 800,000	$ 15,400,000	$ 3,400,000