Derivative Instruments (Fair Values of Derivative Assets and Liabilities) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Assets:
Current	$ 395.8	$ 394.2
Long-term	2,152.0	2,102.5
Total	2,547.8	2,496.7
Liabilities:
Current	379.7	328.4
Long-term	964.7	1,042.3
Total	1,344.4	1,370.7
Cross-currency and interest rate derivative contracts
Assets:
Current	372.3	372.7
Long-term	1,405.7	1,370.1
Total	1,778.0	1,742.8
Liabilities:
Current	371.5	326.5
Long-term	964.7	1,042.2
Total	1,336.2	1,368.7
Equity-related derivative instruments
Assets:
Current	14.6	13.9
Long-term	746.2	732.4
Total	760.8	746.3
Liabilities:
Current	1.3	1.4
Long-term	0.0	0.0
Total	1.3	1.4
Foreign currency forward and option contracts
Assets:
Current	8.4	7.2
Long-term	0.0	0.0
Total	8.4	7.2
Liabilities:
Current	6.9	0.5
Long-term	0.0	0.0
Total	6.9	0.5
Other
Assets:
Current	0.5	0.4
Long-term	0.1	0.0
Total	0.6	0.4
Liabilities:
Current	0.0	0.0
Long-term	0.0	0.1
Total	$ 0.0	$ 0.1