Derivative Instruments - Narrative (Details) $ in Thousands, € in Millions	3 Months Ended	6 Months Ended		24 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Dec. 31, 2011 USD ($) instrument	Jun. 30, 2017 EUR (€) instrument
Derivative [Line Items]
Amortization of interest expense		$ 659	$ 758
Amount to be recognized from hedged transactions within 12 months, approximate		6,600
Other (Income) Expense Net
Derivative [Line Items]
Gain on derivatives	$ 5,100	$ 5,500
4.2% Senior Notes, due December 2021
Derivative [Line Items]
Interest rate on senior notes				4.20%
4.5% Senior Notes, due December 2020
Derivative [Line Items]
Interest rate on senior notes				4.50%
Interest Rate Contract
Derivative [Line Items]
Number of instruments held | instrument				2
Interest Rate Exchange Agreement Expiring 2010 and 2011
Derivative [Line Items]
Amortization of interest expense				$ 68,900
Term of amortized interest expense, years				10 years
Forward exchange contracts
Derivative [Line Items]
Number of instruments held | instrument					4
Notional amount | €					€ 180