Debt Notes (Details) (USD $)	6 Months Ended			6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Mar. 31, 2013 Term Loan [Member]	Jun. 30, 2014 2.375% Notes [Member]	Jun. 30, 2014 4.50% Notes [Member]	Jun. 30, 2014 Unsecured Debt [Member]
Debt Instrument [Line Items]
Notes, net	$ 5,923,952,000	$ 5,477,088,000
Term Loan Principal Amount			750,000,000
Proceeds from Issuance of Unsecured Debt				450,000,000	750,000,000
Debt Instrument, Interest Rate, Stated Percentage				2.375%	4.50%
Proceeds from Debt, Net of Issuance Costs				$ 449,600,000	$ 744,700,000
Debt Instrument, Interest Rate, Effective Percentage Rate Range, Maximum				2.52%	4.57%
Debt Instrument, Maturity Date Range, End	Dec. 31, 2044
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum	0.03%					2.375%
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum	7.25%					7.57%
Weighted Average Interest Rate	4.97%