Commitments (Leases, Future Minimum Payments Due) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014
Future Commitments for Capital Leases:
2015	$ 10
2016	10
2017	10
2018	10
2019	10
Thereafter	109
Total	159
Less: Imputed interest	96
Present value of total minimum lease payments	63
Future Commitments for Operating Leases:
2015	57
2016	57
2017	57
2018	57
2019	75
Thereafter	502
Total	$ 805