Leases (Leases Balances) (Details) € in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2019 EUR (€)	Dec. 31, 2018 EUR (€)
ROU assets
Finance leases	$ 531.0	$ 545.5
Operating leases	512.7
Total	1,043.7
Lease liabilities
Finance leases	617.1
Operating leases	545.1
Total	$ 1,162.2
Weighted average remaining lease term for finance leases	23 years 9 months 18 days			23 years 9 months 18 days
Weighted average discount rate for finance leases	6.10%			6.10%
Finance leases obtained	$ 66.9
ROU assets associated with finance and operating leases	$ 2,880.5	3,705.6	$ 3,703.5
Finance lease		621.3
Weighted average remaining lease term for operating leases	8 years			8 years
Weighted average discount rate for operating leases	4.00%			4.00%
Addition to ROU assets associated with operating leases	$ 88.5
Assets Held under Capital Leases
Lease liabilities
ROU assets associated with finance and operating leases		102.4	$ 106.7
Boarding Communications Network
Lease liabilities
Finance leases	$ 453.2			€ 403.6
Finance lease		$ 447.3			€ 390.6
Lease term	15 years			15 years