Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [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, 2020, 2019, and 2018 using a Black Scholes-Merton Model:

	2020			2019			2018
Director and Officers:
Expected dividend yield	$	0.33		$	0.32		$	0.26
Expected volatility	31.63		%	29.54		%	29.73		%
Risk-free interest rate	0.64		%	2.40		%	2.20		%
Expected life (in years)	5.00			5.00			5.00
Employees:
Expected dividend yield	$	0.32		$	0.32		$	0.26
Expected volatility	31.39		%	29.54		%	29.82		%
Risk-free interest rate	0.67		%	2.38		%	2.51		%
Expected life (in years)	5.00			5.00			5.00

Summary of Stock Options Outstanding

The following is a summary of stock options vested and exercisable as of December 31, 2020:

		Weighted Average	Weighted
Range of	Number	Remaining	Average
Exercise	of	Contractual	Exercise		Intrinsic
Prices	Shares	Life	Price		Value
					(in thousands)
$7.18 - 36.95	543,646	5.33	$	28.33	$	20,820
$37.00 - 40.87	1,978	7.09	38.50		56
$41.37 - 66.98	194,697	7.87	41.59		4,875
Total	740,321	6.00	$	31.85	$	25,751

The following is a summary of stock options vested and exercisable as of December 31, 2019:

		Weighted Average	Weighted
Range of	Number	Remaining	Average
Exercise	of	Contractual	Exercise		Intrinsic
Prices	Shares	Life	Price		Value
					(in thousands)
$7.18 - 34.10	451,077	5.44	$	23.47	$	11,702
$34.15 - 40.87	86,122	7.82	36.33		1,126
$41.37 - 50.68	1,750	1.81	41.59		14
Total	538,949	5.81	$	21.58	$	12,842

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

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, 2019	3,627,047	$	36.32
Granted	1,053,302	45.13
Exercised	(644,850)	33.21
Forfeited or Expired	(282,554)	40.64
Outstanding at December 31, 2020	3,752,945	$	39.00
Exercisable at December 31, 2020	740,321	$	31.85

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, 2019	267,484	$	34.42
Granted	76,148	43.54
Vested	(110,075)	32.55
Forfeited	(8,866)	39.72
Unvested at December 31, 2020	224,691	$	38.22

Summary of Grant Date Fair Value of Awards During Period

	2020		2019		2018
Grant date fair value of awards during the period:	(in thousands)
Options	$	12,615	$	20,442	$	12,932
Restricted stock	3,316		4,631		3,609
Total	$	15,931	$	25,073	$	16,541

Summary of Share-Based Compensation Expense

	2020		2019		2018
Share-based compensation expense:	(in thousands)
Options	$	8,312	$	9,145	$	5,344
Restricted stock	3,030		2,654		2,518
Total	$	11,342	$	11,799	$	7,862

Summary of Income Tax Benefit Related to Share-Based Compensation

	2020		2019		2018
Income tax benefit related to share-based compensation:	(in thousands)
Options	$	2,698	$	1,197	$	980
Restricted stock	519		575		353
Total	$	3,217	$	1,772	$	1,333