Schedule of Valuation and Qualifying Accounts Disclosure (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 5		$ 6		$ 13
Charged to Expense	(1)		4		(1)
Deductions	0	[1]	0	[1]	(5)	[1]
Charged to Other Accounts	0		(5)		(1)
Balance at End of Year	4		5		6
Deferred Tax Asset Valuation Allowance [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	2,246		2,222		2,336
Charged to Expense	(410)		24		(114)
Deductions	0	[1]	0	[1]	0	[1]
Charged to Other Accounts	0		0		0
Balance at End of Year	$ 1,836		$ 2,246		$ 2,222

[1] Represents write-offs of accounts considered to be uncollectible and previously reserved.