Pension Plans and Other Postretirement Benefits (Tables)

9 Months Ended

Sep. 30, 2012

Table Text Block [Abstract]

Components of Net Periodic Benefit Cost Table

	Pension Benefits				Other Benefits
millions	2012		2011		2012		2011
Three Months Ended September 30
Service cost	$	19	$	20	$	2	$	3
Interest cost		21		21		4		4
Expected return on plan assets		(23)		(21)		—		—
Amortization of net actuarial loss (gain)		23		22		—		—
Net periodic benefit cost	$	40	$	42	$	6	$	7

Nine Months Ended September 30
Service cost	$	57	$	59	$	7	$	7
Interest cost		64		64		12		12
Expected return on plan assets		(68)		(64)		—		—
Amortization of net actuarial loss (gain)		69		64		—		—
Amortization of net prior service cost (credit)		—		1		1		—
Net periodic benefit cost	$	122	$	124	$	20	$	19