Common Equity (Tables)

9 Months Ended

Sep. 30, 2015

Common Equity (Tables) [Abstract]

Assumptions for valuing options using binomial option pricing model

	Nine Months Ended September 30
	2015			2014
Non-qualified stock options granted	516,475			899,500
Estimated fair value per non-qualified stock option	$	5.29		$	4.18
Assumptions used to value the options using a binomial option pricing model:
Risk-free interest rate	0.1% – 2.1%			0.1% – 3.0%
Dividend yield	3.7		%	3.8		%
Expected volatility	18.0		%	18.0		%
Expected forfeiture rate	2.0		%	2.0		%
Expected life (years)	5.8			5.8

Stock option activity

The following is a summary of our stock option activity for the three and nine months ended September 30, 2015:

					Weighted-Average
					Remaining	Aggregate
	Number of		Weighted-Average		Contractual Life	Intrinsic Value
Stock Options	Options		Exercise Price		(in years)	(in millions)
Outstanding as of July 1, 2015	6,750,930		$	32.32
Granted	—		$	—
Exercised	(599,752	)	$	23.72
Outstanding as of September 30, 2015	6,151,178		$	33.16
Outstanding as of January 1, 2015	6,770,194		$	29.99
Granted	516,475		$	52.90
Exercised	(1,135,491	)	$	23.25
Outstanding as of September 30, 2015	6,151,178		$	33.16	5.8	$	117.2
Exercisable as of September 30, 2015	3,419,728		$	26.49	4.0	$	88.0

Restricted stock activity

The following restricted stock activity occurred during the three and nine months ended September 30, 2015:

			Weighted-Average
Restricted Shares	Number of Shares		Grant Date Fair Value
Outstanding as of July 1, 2015	147,214		$	45.43
Granted	82,943		$	49.17
Released	—		$	—
Forfeited	(181	)	$	46.16
Outstanding as of September 30, 2015	229,976		$	46.78
Outstanding as of January 1, 2015	155,479		$	38.45
Granted	143,107		$	51.13
Released	(68,429	)	$	36.95
Forfeited	(181	)	$	46.16
Outstanding as of September 30, 2015	229,976		$	46.78

Shares Repurchased

The following table identifies shares purchased in the following periods:

	Nine Months Ended September 30
	2015			2014
(in millions)	Shares	Cost		Shares	Cost
Under share repurchase program	—	$	—	0.4	$	18.6
To fulfill exercised stock options and restricted stock awards	1.3	66.1		1.5	65.6
Total	1.3	$	66.1	1.9	$	84.2

Dividends Declared

During the quarter ended June 30, 2015, our Board of Directors declared common stock dividends which are summarized below:

Date Declared	Date Payable	Per Share	Period
April 16, 2015	June 1, 2015	$0.4225	Second Quarter
June 12, 2015	July 6, 2015	$0.2067	45 days through June 28, 2015
June 12, 2015	September 1, 2015	$0.2337	47 days through Aug. 14, 2015