Long-lived Assets (Schedule of Intangible Assets Subject to Amortization, Net) (Details) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Gross carrying amount | $ 4,194.4 | $ 4,572.9 |
| Accumulated amortization | (3,163.2) | (2,964.4) |
| Net carrying amount | 1,031.2 | 1,608.5 |
| Customer relationships | ||
| Gross carrying amount | 3,673.1 | 4,041.0 |
| Accumulated amortization | (2,914.2) | (2,745.8) |
| Net carrying amount | 758.9 | 1,295.2 |
| Other | ||
| Gross carrying amount | 521.3 | 531.9 |
| Accumulated amortization | (249.0) | (218.6) |
| Net carrying amount | $ 272.3 | $ 313.3 |
| Minimum | Customer relationships | ||
| Estimated useful life | 2 years | |
| Minimum | Other | ||
| Estimated useful life | 2 years | |
| Maximum | Customer relationships | ||
| Estimated useful life | 10 years | |
| Maximum | Other | ||
| Estimated useful life | 20 years |