Leases Leases - Future Minimum Rental Commitments (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014
Leases [Abstract]
Capital Leases, Due 2015	$ 21
Capital Leases, Due 2016	11
Capital Leases, Due 2017	2
Capital Leases, Due 2018	0
Capital Leases, Due 2019	0
Capital Leases, Due 2020 and thereafter	0
Capital Leases, Total minimum rental commitments	34
Capital Leases: Less amounts representing interest	(2)
Capital Leases, Present value of net minimum lease payments	32
Noncancelable Operating Leases, Due 2015	68
Noncancelable Operating Leases, Due 2016	65
Noncancelable Operating Leases, Due 2017	60
Noncancelable Operating Leases, Due 2018	60
Noncancelable Operating Leases, Due 2019	59
Noncancelable Operating Leases, Due 2020 and thereafter	968
Noncancelable Operating Leases, Total minimum rental commitments	$ 1,280