Fair Value Measurements (Summary of Assets and Liabilities at Fair Value) (Schedule) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Assets:
Derivative instruments	$ 1,409.1	$ 1,204.2
Investments, fair value	3,573.3	3,481.8
Total assets	4,982.4	4,686.0
Liabilities:
Derivative instruments	3,542.7	3,056.5
Total liabilities	3,542.7	3,056.5
Quoted prices in active markets for identical assets (Level 1)
Assets:
Derivative instruments	0	0
Investments, fair value	3,251.9	3,182.4
Total assets	3,251.9	3,182.4
Liabilities:
Total liabilities	0	0
Significant other observable inputs (Level 2)
Assets:
Derivative instruments	984.0	773.8
Investments, fair value	0	0
Total assets	984.0	773.8
Liabilities:
Total liabilities	3,437.6	2,939.6
Significant unobservable inputs (Level 3)
Assets:
Derivative instruments	425.1	430.4
Investments, fair value	321.4	299.4
Total assets	746.5	729.8
Liabilities:
Total liabilities	105.1	116.9
Cross-currency and interest rate derivative contracts
Assets:
Derivative instruments	980.6	769.2
Liabilities:
Derivative instruments	3,434.7	2,918.6
Cross-currency and interest rate derivative contracts | Quoted prices in active markets for identical assets (Level 1)
Assets:
Derivative instruments	0	0
Liabilities:
Derivative instruments	0	0
Cross-currency and interest rate derivative contracts | Significant other observable inputs (Level 2)
Assets:
Derivative instruments	980.6	769.2
Liabilities:
Derivative instruments	3,434.7	2,918.6
Cross-currency and interest rate derivative contracts | Significant unobservable inputs (Level 3)
Assets:
Derivative instruments	0	0
Liabilities:
Derivative instruments	0	0
Equity-related derivative instruments
Assets:
Derivative instruments	425.1	430.4
Liabilities:
Derivative instruments	105.1	116.9
Equity-related derivative instruments | Quoted prices in active markets for identical assets (Level 1)
Assets:
Derivative instruments	0	0
Liabilities:
Derivative instruments	0	0
Equity-related derivative instruments | Significant other observable inputs (Level 2)
Assets:
Derivative instruments	0	0
Liabilities:
Derivative instruments	0	0
Equity-related derivative instruments | Significant unobservable inputs (Level 3)
Assets:
Derivative instruments	425.1	430.4
Liabilities:
Derivative instruments	105.1	116.9
Foreign currency forward contracts
Assets:
Derivative instruments	1.3	2.6
Liabilities:
Derivative instruments	2.6	20.2
Foreign currency forward contracts | Quoted prices in active markets for identical assets (Level 1)
Assets:
Derivative instruments	0	0
Liabilities:
Derivative instruments	0	0
Foreign currency forward contracts | Significant other observable inputs (Level 2)
Assets:
Derivative instruments	1.3	2.6
Liabilities:
Derivative instruments	2.6	20.2
Foreign currency forward contracts | Significant unobservable inputs (Level 3)
Assets:
Derivative instruments	0	0
Liabilities:
Derivative instruments	0	0
Other
Assets:
Derivative instruments	2.1	2.0
Liabilities:
Derivative instruments	0.3	0.8
Other | Quoted prices in active markets for identical assets (Level 1)
Assets:
Derivative instruments	0	0
Liabilities:
Derivative instruments	0	0
Other | Significant other observable inputs (Level 2)
Assets:
Derivative instruments	2.1	2.0
Liabilities:
Derivative instruments	0.3	0.8
Other | Significant unobservable inputs (Level 3)
Assets:
Derivative instruments	0	0
Liabilities:
Derivative instruments	$ 0	$ 0