Fair Value Measurements (Summary of Assets and Liabilities at Fair Value) (Schedule) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Assets:
Derivative instruments	$ 1,958.8	$ 1,761.4
Investments, fair value	1,928.8	1,662.7
Total assets	3,887.6	3,424.1
Liabilities:
Derivative instruments	2,256.7	2,560.8
Total liabilities	2,256.7	2,560.8
Quoted prices in active markets for identical assets (Level 1)
Assets:
Derivative instruments	0.0	0.0
Investments, fair value	1,608.7	1,344.3
Total assets	1,608.7	1,344.3
Liabilities:
Total liabilities	0.0	0.0
Significant other observable inputs (Level 2)
Assets:
Derivative instruments	1,624.1	1,361.2
Investments, fair value	0.0	0.0
Total assets	1,624.1	1,361.2
Liabilities:
Total liabilities	1,991.4	2,472.4
Significant unobservable inputs (Level 3)
Assets:
Derivative instruments	334.7	400.2
Investments, fair value	320.1	318.4
Total assets	654.8	718.6
Liabilities:
Total liabilities	265.3	88.4
Cross-currency and interest rate derivative contracts
Assets:
Derivative instruments	1,616.7	1,357.3
Liabilities:
Derivative instruments	1,981.9	2,471.3
Cross-currency and interest rate derivative contracts | Quoted prices in active markets for identical assets (Level 1)
Assets:
Derivative instruments	0.0	0.0
Liabilities:
Derivative instruments	0.0	0.0
Cross-currency and interest rate derivative contracts | Significant other observable inputs (Level 2)
Assets:
Derivative instruments	1,616.7	1,357.3
Liabilities:
Derivative instruments	1,981.9	2,471.3
Cross-currency and interest rate derivative contracts | Significant unobservable inputs (Level 3)
Assets:
Derivative instruments	0.0	0.0
Liabilities:
Derivative instruments	0.0	0.0
Equity-related derivative instruments
Assets:
Derivative instruments	334.7	400.2
Liabilities:
Derivative instruments	265.3	88.4
Equity-related derivative instruments | Quoted prices in active markets for identical assets (Level 1)
Assets:
Derivative instruments	0.0	0.0
Liabilities:
Derivative instruments	0.0	0.0
Equity-related derivative instruments | Significant other observable inputs (Level 2)
Assets:
Derivative instruments	0.0	0.0
Liabilities:
Derivative instruments	0.0	0.0
Equity-related derivative instruments | Significant unobservable inputs (Level 3)
Assets:
Derivative instruments	334.7	400.2
Liabilities:
Derivative instruments	265.3	88.4
Foreign currency forward contracts
Assets:
Derivative instruments	4.9	2.5
Liabilities:
Derivative instruments	9.3	0.8
Foreign currency forward contracts | Quoted prices in active markets for identical assets (Level 1)
Assets:
Derivative instruments	0.0	0.0
Liabilities:
Derivative instruments	0.0	0.0
Foreign currency forward contracts | Significant other observable inputs (Level 2)
Assets:
Derivative instruments	4.9	2.5
Liabilities:
Derivative instruments	9.3	0.8
Foreign currency forward contracts | Significant unobservable inputs (Level 3)
Assets:
Derivative instruments	0.0	0.0
Liabilities:
Derivative instruments	0.0	0.0
Other
Assets:
Derivative instruments	2.5	1.4
Liabilities:
Derivative instruments	0.2	0.3
Other | Quoted prices in active markets for identical assets (Level 1)
Assets:
Derivative instruments	0.0	0.0
Liabilities:
Derivative instruments	0.0	0.0
Other | Significant other observable inputs (Level 2)
Assets:
Derivative instruments	2.5	1.4
Liabilities:
Derivative instruments	0.2	0.3
Other | Significant unobservable inputs (Level 3)
Assets:
Derivative instruments	0.0	0.0
Liabilities:
Derivative instruments	$ 0.0	$ 0.0