Benefit Plans (Impact of One Point Change in Assumptions) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014
Defined Benefit Plan Assumptions Sensitivity To Changes [Abstract]
Increase of 1% in the discount rate	$ (50)
Decrease of 1% in the discount rate	42
Increase of 1% in the long-term rate of return on plan assets	(45)
Decrease of 1% in the long-term rate of return on plan assets	$ 45