Commitments and Contingencies (Operating Leases as Lessee) (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Commitments and Contingencies Disclosure [Abstract] | |||
| Rental costs | $ 58.8 | $ 58.9 | $ 51.5 |
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|