Investment In Unconsolidated Affiliates Narrative (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
HPC [Member]
Ownership in affiliate	49.99%
MEP {Member]
Ownership in affiliate	50.00%
Lone Star {Member]
Ownership in affiliate	30.00%
Ranch JV {Member]
Ownership in affiliate	33.33%
Aqua - PVR [Member]
Ownership in affiliate	51.00%
Coal Handling [Member]
Ownership in affiliate	50.00%
Grey Ranch JV [Member]
Ownership in affiliate	50.00%
Equity Method Investment, Cash Settlement	$ 4
Gain (Loss) on Sale of Equity Investment	$ (1)