Common Equity (Tables)

3 Months Ended

Mar. 31, 2013

Common Equity (Tables) [Abstract]

Shares Repurchased [Table Text Block]

	Three Months Ended March 31
	2013			2012
	Shares	Cost		Shares	Cost
	(In Millions)
Under May 2011 share repurchase program	0.3	$	11.1	—	$	—
To fulfill exercised stock options and restricted stock awards	1.4	55.4		0.8	28.3
Total	1.7	$	66.5	0.8	$	28.3

Assumptions for valuing options using binomial option pricing model

	2013		2012
Risk-free interest rate	0.1% - 1.9%		0.1% - 2.0%
Dividend yield	3.7	%	3.9	%
Expected volatility	18.0	%	19.0	%
Expected forfeiture rate	2.0	%	2.0	%
Expected life (years)	5.9		5.9

Stock option activity

					Weighted-
					Average
			Weighted-		Remaining	Aggregate
	Number of		Average		Contractual Life	Intrinsic Value
Stock Options	Options		Exercise Price		(Years)	(Millions)
Outstanding as of January 1, 2013	8,919,669		$	23.86
Granted	1,418,560		$	37.46
Exercised	(1,274,206	)	$	21.40
Forfeited	—		$	—
Outstanding as of March 31, 2013	9,064,023		$	26.34	5.9	$	150.0
Exercisable as of March 31, 2013	6,633,593		$	22.92	4.7	$	132.5

Stock options outstanding

	Options Outstanding				Options Exercisable
		Weighted-Average				Weighted-Average
				Remaining				Remaining
	Number of	Exercise		Contractual	Number of	Exercise		Contractual
Range of Exercise Prices	Options	Price		Life (Years)	Options	Price		Life (Years)
$16.72 to $21.11	2,733,433	$	20.10	4.2	2,733,433	$	20.10	4.2
$23.88 to $29.35	3,976,660	$	24.65	5.0	3,661,370	$	24.24	4.7
$34.87 to $37.46	2,353,930	$	36.43	9.4	238,790	$	34.90	8.8
	9,064,023	$	26.34	5.9	6,633,593	$	22.92	4.7

Non-vested options

			Weighted-Average
Non-Vested Stock Options	Number of Options		Fair Value
Non-vested as of January 1, 2013	1,702,275		$	3.31
Granted	1,418,560		$	3.45
Vested	(690,405	)	$	3.33
Forfeited	—		$	—
Non-vested as of March 31, 2013	2,430,430		$	3.38

Restricted stock activity

			Weighted-Average
Restricted Shares	Number of Shares		Grant Date Fair Value
Outstanding as of January 1, 2013	188,222
Granted	74,290		$	37.65
Released	(83,085	)	$	27.68
Forfeited	(11,698	)	$	33.01
Outstanding as of March 31, 2013	167,729