Credit Agreements (Details) $ in Thousands, € in Millions	1 Months Ended	3 Months Ended
	May. 31, 2013 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2015 EUR (€)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Jun. 12, 2015 USD ($)	Jul. 25, 2013	Mar. 22, 2013 USD ($)
Line of Credit Facility [Line Items]
Derivative, Notional Amount				$ 408,100	$ 468,600
Letters of Credit Outstanding, Amount				9,900
Long-term Debt, Gross				$ 485,700		$ 7,100
Max commitment fee on revolving loan unused amount, percentage		0.30%
Interest rate swap, fixed interest rate	0.73%		1.30%	1.30%
JP Morgan [Member]
Line of Credit Facility [Line Items]
Transfers of Financial Assets Including Debt Activity		$ 40,000
Other Short-term Borrowings				$ 0
JP Morgan UK [Member]
Line of Credit Facility [Line Items]
Credit agreement maximum borrowing capacity				4,500
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum		2.00%
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum		4.00%
Remaining borrowing available under revolving credit facility				4,500
RBSNederlandNV [Member]
Line of Credit Facility [Line Items]
Credit agreement maximum borrowing capacity | €			€ 4.0
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum		2.00%
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum		4.00%
Remaining borrowing available under revolving credit facility | €			€ 4.0
Interest Rate Swap [Member]
Line of Credit Facility [Line Items]
Principal amount of debt hedged with an interest rate swap agreement	$ 100,000	$ 100,000
Senior Notes due in 2020 [Member]
Line of Credit Facility [Line Items]
Deferred Finance Costs, Noncurrent, Net				300
2013 Credit Agreement LIBOR [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.75%
2013 Credit Agreement [Member]
Line of Credit Facility [Line Items]
Deferred Finance Costs, Noncurrent, Net				$ 2,400	2,500
Debt, Weighted Average Interest Rate			0.00%	0.00%
Swingline Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Current Borrowing Capacity								$ 75,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Face Amount								200,000
Line of Credit Facility, Current Borrowing Capacity								300,000
Letters of Credit Outstanding, Amount								10,000
Remaining borrowing available under revolving credit facility				$ 120,000
2013 Credit Agreement One Month LIBOR Margin [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		0.75%
2013 Credit Agreement Swingline [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		0.75%
Term Loan [Member]
Line of Credit Facility [Line Items]
Long-term Debt								$ 200,000
Senior Notes due in 2020 [Member] | Senior Notes [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Interest Rate, Stated Percentage							3.11%
Long-term Debt, Gross				100,000
Designated as Hedging Instrument [Member]
Line of Credit Facility [Line Items]
Derivative, Notional Amount				280,700	$ 340,600
Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Line of Credit Facility [Line Items]
Derivative, Notional Amount				$ 100,000