Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2018

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

Stock Options, Valuation Assumptions

The weighted-average fair value of options granted and the weighted-average assumptions used in the Black-Scholes-Merton option pricing model for such grants were as follows:

	2018			2017			2016
Dividend Yield	0.3		%	0.4		%	0.4		%
Expected Volatility	34.8		%	32.8		%	34.2		%
Risk-free Interest Rate	2.6		%	1.9		%	1.3		%
Expected Term (in years)	5.3			5.3			5.3
Weighted-average Fair Value of Stock Options Granted	$	16.54		$	8.55		$	7.10

Summary Information about Stock Options Outstanding

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

	Options Outstanding				Options Exercisable
Range of Exercise Prices	Number Outstanding December 31, 2018	Weighted Average Remaining Contractual Life (in Years)	Weighted Average Exercise Price		Number Exercisable December 31, 2018	Weighted Average Exercise Price
$19.92-20.00	33,250	1.15	$	19.92	33,250	$	19.92
20.01-30.00	1,174,285	7.29	25.50		666,915	25.47
30.01-40.00	116,496	6.07	32.13		116,496	32.13
40.01-47.26	352,650	9.18	47.26		—	—
19.92-47.26	1,676,681	7.48	30.42		816,661	26.20

Summary of Stock Option Activity

The table below summarizes option activity for the year ended December 31, 2018:

	Options (In Thousands)		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in Years)	Aggregate Intrinsic Value (in Thousands)		Weighted Average Fair Value
Outstanding at January 1, 2018	1,652		$	25.56
Granted	361		47.26
Exercised	(296	)	23.90
Forfeited/expired	(40	)	29.77
Outstanding at December 31, 2018	1,677		30.42		7.48	$	19,496	$	9.98
Expected to Vest	844		34.20		8.35	6,624		11.42
Exercisable at December 31, 2018	817		26.20		6.55	12,947		8.36

Summary of Restricted Stock Activity

The following table summarizes information about restricted stock activity during 2018:

	Restricted Stock (In Thousands)		Weighted Average Fair Value
Non-vested at January 1, 2018	947		$	27.96
Granted	248		46.01
Vested	(544	)	28.33
Forfeited	(62	)	37.46
Non-vested at December 31, 2018	589		34.18

Summary of Performance Share Units

The following table summarizes information about performance share unit activity during 2018:

	Performance Share Units (In Thousands)		Weighted Average Fair Value
Non-vested at January 1, 2018	822		$	26.31
Granted	486		38.51
Vested	(458	)	26.96
Forfeited/unearned	(51	)	30.06
Non-vested at December 31, 2018	799		33.11