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Fair Value of Financial Instruments #3 (Unaudited) (Details) - Pension Plan [Member] - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2015
Jun. 30, 2014
Jun. 30, 2015
Jun. 30, 2014
Defined Benefit Plan Disclosure [Line Items]        
Defined benefit plan, contributions by Employer $ 19 $ 18 $ 544 $ 39
Voluntary Contributions [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Defined benefit plan, contributions by Employer     $ 500