Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Components of the Company’s stock-based compensation expense

The following table summarizes the components of stock-based compensation expense included in general and administrative expenses in the Consolidated Statements of Comprehensive Income for the three and nine months ended September 30, 2015 and 2014:

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2015			2014			2015			2014
	(In millions)
Total stock-based compensation expense:
Equity classified awards expense	$	1.8		$	1.9		$	6.4		$	7.5
Liability classified awards expense (credit)	0.3			0.7			(0.5		)	1.2
Total pre-tax stock-based compensation expense	2.1			2.6			5.9			8.7
Book income tax benefit	(0.8		)	(1.0		)	(2.2		)	(3.3		)
Total stock-based compensation expense, net of tax	$	1.3		$	1.6		$	3.7		$	5.4

Schedule of stock option valuation assumptions

The following summarizes the assumptions used in the Black-Scholes model:

Risk-free interest rate	1.54	%
Weighted average historical volatility	36.8	%
Dividend yield	3.17	%
Expected years until exercise	4.5
Weighted average fair value of options granted	$27.20

Schedule of stock option activity

Stock option balances as of September 30, 2015 and related activity for the nine months ended September 30, 2015 were as follows:

	Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in Years)	Aggregate Intrinsic Value (in Millions)
Outstanding at December 31, 2014	618,115		$	53.10
Granted	133,814		111.54
Exercised	(198,221	)	42.51
Forfeited	(26,386	)	100.45
Outstanding at September 30, 2015	527,322		69.55		6.8	$14.5
Vested at September 30, 2015 and Expected to Vest	502,780		67.97		6.7	$14.4
Exercisable at September 30, 2015	330,734		$	52.71	5.6	$13.4

Schedule of restricted stock unit activity

Outstanding balances as of September 30, 2015 and activity related to restricted stock and restricted stock units for the nine months ended September 30, 2015 were as follows:

	Restricted Stock		Weighted Average Grant Date Fair Value		Restricted Stock Units		Weighted Average Grant Date Fair Value
Outstanding at December 31, 2014	233,818		$	70.14	41,622		$	66.92
Granted	117,896		105.55		10,294		113.72
Released	(73,595	)	53.77		(16,567	)	52.19
Forfeited	(30,132	)	85.25		(72	)	113.72
Outstanding at September 30, 2015	247,987		$	90.01	35,277		$	86.49