Derivative Financial Instruments and Risk Management (Details 4) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Derivative
Balance at beginning of period, net of tax			$ (5)	$ (5)
Gains (losses) deferred during the period, net of tax	$ (1)	$ (1)	0	(5)
(Gains) losses reclassified to earnings, net of tax	1	1	3	3
Balance at end of period, net of tax	(2)	(7)	(2)	(7)
Beginning balance, tax			3	3
Gains (losses) deferred during the period, tax	0	1	(1)	2
(Gains) losses reclassified to earnings, tax	0	(1)	(1)	(1)
Ending balance, tax	$ 1	$ 4	$ 1	$ 4