Employment Benefit Plans Level 3 Rollforward (Details) (Pension Benefits, USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2014		Dec. 31, 2013
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance		$ 2,342,000,000	[1]	$ 2,490,000,000	[2]
Ending balance		2,342,000,000	[1]	2,490,000,000	[2]
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance		0	[1],[3]	0	[2],[3]
Purchases, Sales, and Settlements	(32,000,000)
Ending balance	32,000,000	0	[1],[3]	0	[2],[3]
Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance				0
Purchases, Sales, and Settlements	(32,000,000)
Ending balance	$ 32,000,000			$ 0

[1] Excludes less than $1 million accrued for dividend and interest receivable.

[2] Excludes $1 million accrued for dividend and interest receivable.

[3] See Note 2 to the Consolidated Financial Statements under the heading “Fair Value Measurements” for a definition of each of these levels of inputs.