Derivative Financial Instruments and Risk Management (Details 4) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Derivative
Balance at beginning of period, net of tax	$ (5)	$ (5)
Gains (losses) deferred during the period, net of tax	1	(2)
(Gains) losses reclassified to earnings, net of tax	1	1
Balance at end of period, net of tax	(3)	(6)
Beginning balance, tax	3	3
Gains (losses) deferred during the period, tax	(1)	0
(Gains) losses reclassified to earnings, tax	0	0
Ending balance, tax	$ 2	$ 3