Condensed Consolidated Statements of Comprehensive Income (Unaudited) (Parentheticals) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Reclassification of losses to net benefit cost, income tax	$ 3	$ 2	$ 7	$ 5
Reclassification of prior service credits arising during the period, tax	(1)	0	(1)	0
Net derivative instruments gain arising during the period, income tax	18	0	1	0
Reclassification of realized derivative instruments (gain) loss to net income, income tax	$ 0	$ 0	$ 0	$ (1)