Retirement Benefits and Trusteed Assets (Tables)

6 Months Ended

Jun. 30, 2011

Retirement Benefits and Trusteed Assets (Tables) [Abstract]

Components of net periodic benefit costs for pension benefits and other postretirement benefits

							Other Postretirement
	Pension Benefits						Benefits
(in Millions)	2011			2010			2011			2010
Three Months Ended June 30
Service cost	$	18		$	16		$	17		$	14
Interest cost		50			51			31			31
Expected return on plan assets		(61	)		(65	)		(23	)		(18	)
Amortization of:
Net actuarial loss		33			25			15			13
Prior service cost		1			1			(6	)		(1	)
Net transition liability		—			—			—			1
Special termination benefits		2			—			—			—
Net periodic benefit cost	$	43		$	28		$	34		$	40

							Other Postretirement
	Pension Benefits						Benefits
(in Millions)	2011			2010			2011			2010
Six Months Ended June 30
Service cost	$	37		$	32		$	34		$	30
Interest cost		101			101			62			63
Expected return on plan assets		(123	)		(129	)		(47	)		(37	)
Amortization of:
Net actuarial loss		66			50			30			27
Prior service cost		2			2			(13	)		(2	)
Net transition liability		—			—			1			1
Special termination benefits		2			—			—			—
Net periodic benefit cost	$	85		$	56		$	67		$	82