Derivative Instruments (Fair Values of Derivative Assets and Liabilities) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Assets (a):
Current	$ 418.8	$ 394.2
Long-term	2,854.2	2,102.5
Total	3,273.0	2,496.7
Liabilities (a):
Current	397.9	328.4
Long-term	1,185.7	1,042.3
Total	1,583.6	1,370.7
Cross-currency and interest rate derivative contracts
Assets (a):
Current	406.7	372.7
Long-term	2,115.0	1,370.1
Total	2,521.7	1,742.8
Liabilities (a):
Current	397.0	326.5
Long-term	1,185.6	1,042.2
Total	1,582.6	1,368.7
Equity-related derivative instruments
Assets (a):
Current	0.0	13.9
Long-term	736.3	732.4
Total	736.3	746.3
Liabilities (a):
Current	0.6	1.4
Long-term	0.0	0.0
Total	0.6	1.4
Foreign currency forward and option contracts
Assets (a):
Current	11.9	7.2
Long-term	2.8	0.0
Total	14.7	7.2
Liabilities (a):
Current	0.3	0.5
Long-term	0.0	0.0
Total	0.3	0.5
Other
Assets (a):
Current	0.2	0.4
Long-term	0.1	0.0
Total	0.3	0.4
Liabilities (a):
Current	0.0	0.0
Long-term	0.1	0.1
Total	$ 0.1	$ 0.1