Taxes (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Changes in unrecognized tax benefits
Beginning balance		$ 43	$ 117	$ 45
Increase due to merger with AE				97
Current year increases			2
Current year decreases			(7)
Prior years increases		10	6	10
Prior years decreases		(5)	(37)	(35)
Decrease for settlements	(34)		(38)
Ending balance	43	48	43	117
FES
Changes in unrecognized tax benefits
Beginning balance		3	45	41
Increase due to merger with AE				0
Current year increases			0
Current year decreases			0
Prior years increases		0	6	8
Prior years decreases		0	(13)	(4)
Decrease for settlements			(35)
Ending balance	$ 3	$ 3	$ 3	$ 45