Share-Based Compensation and Capital Stock (Tables)

12 Months Ended

Dec. 31, 2018

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

Weighted Average Assumptions of Black-Scholes Option-Pricing Model

The fair value of the options granted was estimated on the grant date using the Black-Scholes option-pricing model with the following weighted average assumptions:

	2018			2017			2016
Risk-free interest rate	2.58		%	1.76		%	1.22		%
Expected volatility	21.17		%	21.64		%	23.76		%
Expected life of stock option	4.6 years			4.6 years			4.6 years
Dividend yield	1.05		%	1.42		%	1.59		%
Requisite service period	4 years			4 years			4 years
Contractual life	7 years			7 years			7 years
Weighted average fair value of options granted (per option)	$	16.27		$	10.81		$	9.30

Schedule of Options Outstanding and Exercisable

The following table summarizes information about stock options outstanding at December 31, 2018:

	Options Outstanding				Options Exercisable
Range of Exercise Prices	Number Outstanding at December 31, 2018	Weighted Average Remaining Contractual Life	Weighted Average Exercise Price		Number Exercisable at December 31, 2018	Weighted Average Exercise Price
$34.13 to $39.00	52,664	1.1 years	$	36.76	52,664	$	36.76
$39.01 to $48.75	417,591	2.2 years	$	45.59	417,591	$	45.59
$48.76 to $65.00	610,415	4.0 years	$	56.73	283,426	$	57.77
$65.01 to $81.55	105,510	6.2 years	$	81.55	—	$	—
	1,186,180	3.5 years	$	54.13	753,681	$	49.55

Summary of Activity Related to Restricted Stock Grants

The following table is a summary of activity related to restricted stock grants:

	For the Year Ended December 31,
	2018		2017		2016
Restricted shares granted	101,325		175,644		204,333
Weighted average grant date fair value per share	$	81.21	$	61.84	$	51.53
Aggregate grant date fair value ($000)	$	8,229	$	10,862	$	10,529
Restricted shares forfeited	46,785		30,375		28,996
Vesting service period of shares granted	12 - 48 months		12 - 48 months		12 - 48 months
Fair value of shares vested ($000)	$	8,025	$	12,616	$	7,506

Summary of Activity Related to PVRSU Grants

The following table is a summary of activity related to PVRSU grants:

	For the Years Ended December 31,
	2018		2017		2016
Performance vested restricted stock units granted at target	100,919		162,523		89,944
Weighted average grant date fair value per share	$	81.25	$	60.63	$	47.85
Aggregate grant date fair value ($000)	$	8,200	$	9,853	$	4,304
Stock units forfeited	27,255		74,734		54,556
Requisite service period	36 - 39 months		30 - 36 months		9 - 43 months

Summary of Change in Stock-Based Award Activity

A summary of stock-based award activity as of December 31, 2018, 2017 and 2016 and the changes during the years are presented below:

	2018
	Stock Options					Restricted Stock				Performance Vested Restricted Stock Units
	Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life	Shares		Weighted Average Grant Date Fair Value		Shares		Weighted Average Grant Date Fair Value
Outstanding at January 1, 2018	1,976,326		$	50.80		348,876		$	57.05	294,204		$	56.95
Granted	109,045		$	81.55		101,325		$	81.21	100,919		$	81.25
Exercised/Vested	(832,809	)	$	49.66		(99,651	)	$	55.64	(31,048	)	$	60.60
Expired	(2,018	)	$	63.47		—		$	—	—		$	—
Forfeited	(64,364	)	$	55.79		(46,785	)	$	60.40	(27,255	)	$	64.49
Outstanding at December 31, 2018	1,186,180		$	54.13	3.5 years	303,765		$	65.06	336,820		$	63.28
Options exercisable at December 31, 2018	753,681		$	49.55	2.7 years

	2017
	Stock Options					Restricted Stock				Performance Vested Restricted Stock Units
	Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life	Shares		Weighted Average Grant Date Fair Value		Shares		Weighted Average Grant Date Fair Value
Outstanding at January 1, 2017	2,193,502		$	48.26		407,812		$	50.61	235,980		$	47.59
Granted	195,652		$	60.70		175,644		$	61.84	162,523		$	60.63
Performance-Based Leveraging*	—		$	—		—		$	—	9,491		$	45.59
Exercised/Vested	(353,744	)	$	39.88		(204,205	)	$	48.61	(39,056	)	$	46.22
Expired	(10,133	)	$	56.95		—		$	—	—		$	—
Forfeited	(48,951	)	$	54.12		(30,375	)	$	55.02	(74,734	)	$	39.59
Outstanding at December 31, 2017	1,976,326		$	50.80	4.1 years	348,876		$	57.05	294,204		$	56.95
Options exercisable at December 31, 2017	1,279,500		$	48.76	3.7 years

* PVRSU units outstanding have been increased by 9,491 units during the year ended December 31, 2017, due to the Company exceeding the targeted performance conditions contained in PVRSU's granted in prior periods.

	2016
	Stock Options					Restricted Stock				Performance Vested Restricted Stock Units
	Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life	Shares		Weighted Average Grant Date Fair Value		Shares		Weighted Average Grant Date Fair Value
Outstanding at January 1, 2016	2,084,201		$	41.36		384,490		$	47.40	226,737		$	45.09
Granted	745,769		$	51.49		204,333		$	51.53	89,944		$	47.85
Performance-Based Leveraging*	—		$	—		—		$	—	2,043		$	36.76
Exercised/Vested	(529,210	)	$	24.47		(152,015	)	$	43.61	(28,188	)	$	36.76
Expired	(13,620	)	$	57.62		—		$	—	—		$	—
Forfeited	(93,638	)	$	53.63		(28,996	)	$	51.22	(54,556	)	$	42.82
Outstanding at December 31, 2016	2,193,502		$	48.26	4.6 years	407,812		$	50.61	235,980		$	47.59
Options exercisable at December 31, 2016	816,969		$	40.75	3.3 years

* PVRSU units outstanding have been increased by 2,043 units during the year ended December 31, 2016, due to the Company exceeding the targeted performance conditions contained in PVRSU's granted in prior periods.

Pre-Tax Stock-Based Compensation Expenses and Associated Income Tax Benefits

The components of the Company’s pretax stock-based compensation expense and associated income tax benefits are as follows:

	For the Year Ended December 31,
(In millions)	2018		2017		2016
Stock options	$	2.4	$	9.2	$	4.6
Restricted stock	6.8		9.0		7.5
Performance vested restricted stock units	5.8		6.7		2.5
Total	$	15.0	$	24.9	$	14.6
Income tax benefits	$	3.6	$	9.2	$	5.4

Schedule of Unrecognized Compensation Cost, Nonvested Awards

The total unrecognized compensation costs related to stock-based awards that have not yet vested and the related weighted average amortization period over which the costs are to be recognized as of December 31, 2018 are as follows:

	Unrecognized Compensation Expense on Unvested Awards		Weighted Average Remaining Amortization Period
	(in millions)
Stock options	$	3.0	2.2 years
Restricted stock	12.6		2.3 years
Performance vested restricted stock units	8.9		1.8 years
Total	$	24.5