Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2018

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

Summary of Stock Option Assumptions

The following weighted average assumptions were used to determine the fair value of the stock options granted on the original grant date for expense recognition purposes for options granted during December 31, 2018, 2017, and 2016 using a Black Scholes-Merton Model:

	2018			2017			2016
Director and Officers:
Expected dividend yield	$	0.26		$	0.26		$	0.22
Expected volatility	29.73		%	30.81		%	41.19		%
Risk-free interest rate	2.20		%	1.90		%	2.00		%
Expected life (in years)	5.00			5.00			7.68
Employees:
Expected dividend yield	$	0.26		$	0.26		$	0.25
Expected volatility	29.82		%	30.67		%	34.50		%
Risk-free interest rate	2.51		%	1.89		%	1.73		%
Expected life (in years)	5.00			5.00			5.69

Summary of Stock Options Outstanding

The following is a summary of stock options vested and exercisable as of December 31, 2018:

		Weighted Average	Weighted
Range of	Number	Remaining	Average
Exercise	of	Contractual	Exercise		Intrinsic
Prices	Shares	Life	Price		Value
					(in thousands)
$5.67 - 32.80	456,223	5.72	$	20.25	$	6,757
$32.85 - 34.10	42,552	7.47	33.95		47
$34.15 - 42.94	17,202	8.30	35.19		7
Total	515,977	5.95	$	21.88	$	6,811

The following is a summary of stock options vested and exercisable as of December 31, 2017:

		Weighted Average	Weighted
Range of	Number	Remaining	Average
Exercise	of	Contractual	Exercise		Intrinsic
Prices	Shares	Life	Price		Value
					(in thousands)
$4.54 - 22.76	424,130	4.36	$	12.41	$	10,303
$23.57 - 32.85	107,456	8.31	30.10		709
$32.90 - 37.30	25,725	9.19	34.07		68
Total	557,311	5.35	$	16.82	$	11,080

The following is a summary of stock options vested and exercisable as of December 31, 2016:

		Weighted Average	Weighted
Range of	Number	Remaining	Average
Exercise	of	Contractual	Exercise		Intrinsic
Prices	Shares	Life	Price		Value
					(in thousands)
$4.54 - 20.92	338,308	4.75	$	8.03	$	8,465
$20.96 - 26.50	71,928	8.56	22.50		759
Total	410,236	5.42	$	10.57	$	9,224

Summary of Stock Option Activity

A summary of option activity under the plans is as follows:

			Weighted Average Exercise
Options	Shares		Price
Outstanding at December 31, 2017	1,567,109		$	25.27
Granted	1,480,490		34.49
Exercised	(282,598	)	17.64
Forfeited or Expired	(319,152	)	32.84
Outstanding at December 31, 2018	2,445,849		$	30.77
Exercisable at December 31, 2018	515,977		$	21.89

Summary of Unvested Restricted Stock Awards

A summary of the unvested restricted stock awards is as follows:

			Weighted Average Grant date
Restricted stock	Shares		Fair Value
Unvested at December 31, 2017	341,800		$	25.52
Granted	112,075		32.20
Vested	(124,508	)	23.61
Forfeited	(36,917	)	28.37
Unvested at December 31, 2018	292,450		$	28.54

Summary of Grant Date Fair Value of Awards During Period

	2018		2017		2016
Grant date fair value of awards during the period:	(in thousands)
Options	$	12,932	$	3,699	$	6,102
Restricted stock	3,609		4,217		3,147
Total	$	16,541	$	7,916	$	9,249

Summary of Share-Based Compensation Expense

	2018		2017		2016
Share-based compensation expense:	(in thousands)
Options	$	4,181	$	2,904	$	1,681
Restricted stock	3,193		3,554		2,676
Total	$	7,374	$	6,458	$	4,357

Summary of Income Tax Benefit Related to Share-Based Compensation

	2018		2017		2016
Income tax benefit related to share-based compensation:	(in thousands)
Options	$	980	$	1,413	$	1,610
Restricted stock	353		1,051		458
Total	$	1,333	$	2,464	$	2,068