Compensation and Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2011

Compensation and Benefit Plans

Expense components for pension plan

	Three months ended June 30,						Six months ended June 30,
(in millions)	2011			2010			2011			2010
Service cost	$	43		$	34		$	86		$	68
Interest cost		52			54			104			108
Expected return on plan assets		(60	)		(52	)		(120	)		(104	)
Amortization of prior service cost		2			2			4			4
Amortization of net loss		6			7			12			14
Expense under accounting standards		43			45			86			90
Regulatory adjustment – deferred		(6	)		(14	)		(12	)		(28	)
Total expense recognized	$	37		$	31		$	74		$	62

Expense components for postretirement benefits other than pension

	Three months ended June 30,						Six months ended June 30,
(in millions)	2011			2010			2011			2010
Service cost	$	11		$	8		$	22		$	16
Interest cost		33			31			66			62
Expected return on plan assets		(28	)		(25	)		(56	)		(50	)
Amortization of prior service cost (credit)		(9	)		(9	)		(18	)		(18	)
Amortization of net loss		9			8			18			16
Total expense	$	16		$	13		$	32		$	26

Summary of the status of stock options

				Weighted-Average
	Stock options			Exercise Price		Remaining Contractual Term (Years)		Aggregate Intrinsic Value (in millions)
Outstanding at December 31, 2010		19,142,209		$	33.28
Granted		3,314,149			37.95
Expired		(87,641	)		47.93
Forfeited		(244,066	)		32.52
Exercised		(1,002,771	)		24.74
Outstanding at June 30, 2011		21,121,880			34.37		6.26
Vested and expected to vest at June 30, 2011		20,639,870			34.38		6.21	$	136
Exercisable at June 30, 2011		12,613,025			34.70		4.74		93

Summary of nonvested performance shares

	Equity Awards					Liability Awards
	Shares			Weighted-Average Grant Date Fair Value		Shares			Weighted-Average Fair Value
Nonvested at December 31, 2010		415,028		$	30.99		415,028		$	34.74
Granted		148,697			27.96		148,697
Forfeited		(113,762	)		43.42		(113,762	)
Nonvested at June 30, 2011		449,963			28.04		449,963			29.43

Summary of nonvested restricted stock units

	Restricted Stock Units			Weighted-Average Grant Date Fair Value
Nonvested at December 31, 2010		644,796		$	32.18
Granted		247,408			37.95
Forfeited		(16,467	)		32.13
Paid Out		(104,420	)		52.35
Nonvested at June 30, 2011		771,317		$	31.98

Schedule of Supplemental Data on Stock Based Compensation

		Three months ended June 30,				Six months ended June 30,
(in millions)		2011		2010		2011		2010
Stock based compensation expense1		$	11	$	9	$	17	$	17
Income tax benefits related to stock compensation expense			5		4		7		7
Excess tax benefits2			2		1		4		2
Stock options
	Cash used to purchase shares to settle options		20		6		39		13
	Cash from participants to exercise stock options		12		4		25		9
	Value of options exercised		8		2		14		4
Restricted stock units
	Value of shares settled		—		—		5		—
	Tax benefits realized from settlement of awards		—		—		2		—

¹

Reflected in "Operations and maintenance" on the consolidated statements of income.

²

Reflected in "Settlements of stock based compensation—net" in the financing section of the consolidated statements of cash flows.