Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2017

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:

	Three months ended June 30,						Six months ended June 30,
	2017			2016			2017			2016
	(In millions)
Total stock-based compensation expense:
Equity classified awards expense	$	1.5		$	2.5		$	7.7		$	5.7
Liability classified awards expense	(1.3		)	0.3			(1.1		)	1.1
Total pre-tax stock-based compensation expense	0.2			2.8			6.6			6.8
Book income tax benefit	(0.1		)	(1.1		)	(2.5		)	(2.6		)
Total stock-based compensation expense, net of tax	$	0.1		$	1.7		$	4.1		$	4.2

Schedule of stock option valuation assumptions

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

Risk-free interest rate	1.9	%
Weighted average historical volatility	22.9	%
Dividend yield	7.3	%
Expected years until exercise	4.5
Weighted average fair value of options granted	$4.31

Schedule of stock option activity

Stock option balances as of June 30, 2017, and related activity for the six months ended June 30, 2017 were as follows:

	Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in Years)	Aggregate Intrinsic Value (in Millions)
Outstanding at December 31, 2016	701,134		$	80.04
Granted	537,030		53.42
Exercised	(64,916	)	40.59
Expired	(46,088	)	79.76
Forfeited	(67,033	)	73.84
Outstanding at June 30, 2017	1,060,127		69.38		7.0	$	0.0
Vested at June 30, 2017 and Expected to Vest	962,331		70.58		6.7	$	0.0
Exercisable at June 30, 2017	468,437		$	81.88	3.8	$	0.0

Schedule of restricted stock unit activity

Outstanding balances as of June 30, 2017, and activity related to restricted stock and restricted stock units for the six months ended June 30, 2017 were as follows:

	Restricted Stock		Weighted Average Grant Date Fair Value		Restricted Stock Units		Weighted Average Grant Date Fair Value
Outstanding at December 31, 2016	235,472		$	92.91	34,058		$	93.95
Granted	170,236		54.43		22,926		54.97
Released	(88,341	)	88.83		(12,199	)	81.57
Forfeited	(47,005	)	81.77		—		—
Outstanding at June 30, 2017	270,362		$	71.86	44,785		$	78.15