Long-Term Debt - Additional Information (Details) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended			6 Months Ended
	Feb. 01, 2015	Jan. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Jan. 12, 2015	Dec. 31, 2014	Jan. 20, 2005
Debt Instrument [Line Items]
Proceeds from Issuance of Long-term Debt						$ 1,000,000	$ 0
Repayments of long-term debt						$ 1,331,648	3,016
Weighted average interest rate			0.96%			0.96%
Weighted average maturity period						20 days
Net investment hedge, gain (loss)			$ (10,930)		$ 0	$ 43,116	0
Debt financing costs						1,164	$ 1,372
Revolving Credit Facility
Debt Instrument [Line Items]
Proceeds from Issuance of Long-term Debt		$ 250,000
Repayments of long-term debt				$ 250,000
Bridge Loan
Debt Instrument [Line Items]
Debt Related Commitment Fees and Debt Issuance Costs						$ 2,300
4.625% Senior Notes
Debt Instrument [Line Items]
Debt instrument, face amount								$ 1,250,000
Debt instrument, interest rate			4.625%			4.625%		4.625%
Unamortized Premium			$ 40,203			$ 40,203		$ 43,700
Debt Instrument, Interest Rate, Effective Percentage								3.95%
5.10% Senior Notes
Debt Instrument [Line Items]
Debt instrument, interest rate									5.10%	5.10%
Repayments of long-term debt	$ 325,000
1.875% Senior Notes
Debt Instrument [Line Items]
Debt instrument, interest rate			1.875%			1.875%			1.875%
Short-term Debt | Term Loan
Debt Instrument [Line Items]
Proceeds from Issuance of Long-term Debt		1,000,000
Repayments of long-term debt				1,000,000
Senior Unsecured Cash Bridge Facility | Bridge Loan
Debt Instrument [Line Items]
Proceeds from Issuance of Long-term Debt		$ 800,000
Repayments of long-term debt				$ 800,000