Stock Based Compensation (Tables)

12 Months Ended

Dec. 31, 2011

Stock Based Compensation [Abstract]

Accrual Adjustments

	2011		2010		2009
			Millions
Compensation Cost included in Operation and Maintenance Expense	$	23	$	29	$	27
Income Tax Benefit Recognized in Consolidated Statement of Operations	$	10	$	12	$	11

Stock Options Activity

2011
	Options			Weighted Average Exercise Price
Beginning of Year		3,660,634		$	32.22
Exercised		(263,600	)		23.68
Forfeited		(70,750	)		31.65
Expired		(53,984	)		40.98
End of Year		3,272,300		$	32.78
Exercisable at End of Year		2,641,475		$	32.91

Options	Weighted Average Remaining Years Contractual Term		Aggregate Intrinsic Value
Outstanding at December 31, 2011		5.9	$	8,614,956
Exercisable at December 31, 2011		5.4	$	7,918,875

Weighted Average Assumptions

	2009
Expected Volatility		29.00%
Risk-Free Interest Rate		2.84%
Expected Life (Years)		6.25
Weighted Average Dividend Yield		4.00%

Activity For Options Exercised

	2011		2010		2009
	Millions
Total Intrinsic Value of Options Exercised	$	2	$	1	$	4
Cash Received from Options Exercised	$	6	$	3	$	11
Tax Benefit Realized from Options Exercised	$	1	$	1	$	3

Restricted Stock Activity

	Shares			Weighted Average Grant Date Fair Value		Weighted Average Remaining Years Contractual Term		Aggregate Intrinsic Value
Outstanding at January 1, 2011		117,702		$	35.71
Granted		0		$	0.00
Vested		(47,402	)	$	39.99
Canceled		0		$	0.00
Outstanding at December 31, 2011		70,300		$	32.83		1.1	$	2,320,603

Restricted Stock Units Activity

	Shares			Weighted Average Grant Date Fair Value		Weighted Average Remaining Years Contractual Term		Aggregate Intrinsic Value
Outstanding at January 1, 2011		814,361		$	33.33
Granted		110,845		$	32.03
Vested		(216,158	)	$	36.99
Canceled		(60,497	)	$	40.96
Outstanding at December 31, 2011		648,551		$	31.17		1.5	$	21,408,669

Performance Units Information

	Shares			Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Term		Aggregate Intrinsic Value
Outstanding at January 1, 2011		881,589		$	33.77
Granted		63,250		$	35.33
Vested		(244,406	)	$	30.60
Cancelled		(58,447	)	$	33.78
Outstanding at December 31, 2011		641,986		$	35.13		1.6	$	21,191,958