Accounting for Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2021

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Schedule of Stock-based Compensation Expense

The total stock-based compensation expense for the years ended December 31, 2021, 2020, and 2019, the unrecognized compensation expense at December 31, 2021, and the weighted-average period to recognize the remaining unrecognized shares are as follows: 

	Stock-Based Compensation Expense
	Recognized as of December 31,						Unrecognized
	2021		2020		2019		December 31, 2021		Weighted Average Period to Recognize (years)
Restricted Stock Units	$	8,563	$	11,895	$	10,644	$	13,373		1.6
Cash-Settled Restricted Stock Units		8,251		7,015		10,213		7,062		1.7
Non-Employee Director Awards		937		755		719		460		0.4
Performance Shares		3,731		4,905		4,455		3,768		1.4
Total	$	21,482	$	24,570	$	26,031	$	24,663

Outstanding Stock Option Activity

The following table summarizes the changes in outstanding stock options:

	Number of Shares			Weighted Average Exercise Price		Aggregate Intrinsic Value
Outstanding at January 1, 2019		201,810		$	33.68
Exercised		(93,682	)	$	31.21
Granted		—		$	—
Forfeited/Expired		—		$	—
Outstanding at December 31, 2019		108,128		$	35.82
Exercised		(69,901	)	$	37.94
Granted		—		$	—
Forfeited/Expired		—		$	—
Outstanding at December 31, 2020		38,227		$	31.93
Exercised		(8,535	)	$	27.17
Granted		—		$	—
Forfeited/Expired		—		$	—
Outstanding at December 31, 2021		29,692		$	33.30	$	2,056,051
Vested plus expected to vest at December 31, 2021		29,692		$	33.30	$	2,056,051
Exercisable at December 31, 2021		29,692		$	33.30	$	2,056,051

Schedule of Stock Options Outstanding by Exercise Price Range

Information regarding stock options outstanding as of December 31, 2021 is summarized below:

	OPTIONS OUTSTANDING						OPTIONS EXERCISABLE
Range of Exercise Prices	Number Outstanding As of December 31, 2021		Weighted Average Remaining Contractual Term		Weighted Average Exercise Price		Number Exercisable As of December 31, 2021		Weighted Average Exercise Price
$25.01 to $27.00		3,572		0.2	$	25.66		3,572	$	25.66
$27.01 to $40.00		12,114		1.2	$	27.03		12,114	$	27.03
$40.01 to $41.00		14,006		2.2	$	40.68		14,006	$	40.68
$25.01 to $41.00		29,692		1.6	$	33.30		29,692	$	33.30

Summary of Non-employee Director Awards

Beginning on July 2, 2018, the Company granted awards of registered shares to its non-employee directors on an annual basis under the Omnibus Plan.  A summary of the non-employee director awards is presented below:

	Number of Shares			Weighted- Average Grant Date Fair Value		Aggregate Intrinsic Value
Non-vested RSUs at January 1, 2019		4,968		$	72.35
Granted		9,732		$	73.94
Vested		(9,840	)	$	73.14
Cancelled		—		$	—
Non-vested RSUs at December 31, 2019		4,860		$	73.94
Granted		12,541		$	64.58
Vested		(10,891	)	$	68.82
Cancelled		—		$	—
Non-vested RSUs at December 31, 2020		6,510		$	64.47
Granted		11,186		$	90.73
Vested		(12,110	)	$	76.61
Cancelled		—		$	—
Non-vested RSUs at December 31, 2021		5,586		$	90.73	$	572,844
RSUs expected to vest in the future		5,586		$	90.73	$	572,844

Summary of Performance Shares Activity

A summary of the Company’s PSAs is presented below.

	Number of Shares			Weighted- Average Grant Date Fair Value		Aggregate Intrinsic Value
Non-vested PSAs at January 1, 2019		169,486		$	45.15
Granted		85,928		$	62.07
Vested		(107,000	)	$	37.21
Cancelled		—		$	—
Non-vested PSAs at December 31, 2019		148,414		$	60.67
Granted		87,314		$	51.44
Vested		(88,038	)	$	38.81
Cancelled		(5,569	)	$	69.66
Non-vested PSAs at December 31, 2020		142,121		$	68.19
Granted		54,216		$	85.03
Vested		(63,258	)	$	65.05
Cancelled		—		$	—
Non-vested PSAs at December 31, 2021		133,079		$	76.54	$	13,647,251
PSAs expected to vest in the future		85,540		$	73.38	$	8,772,127

Schedule of Fair Value Assumptions using Monte Carlo Simulation Model for Awards Granted

The fair value assumptions using the Monte Carlo simulation model for awards granted in 2021, 2020, and 2019 were:

	2021			2020			2019
Dividend Yield		0.6	%		1.0	%		0.7	%
Historical Volatility		40.9	%		35.7	%		29.3	%
Risk-Free Rate of Returns		0.3	%		0.4	%		2.4	%

Restricted Stock Units (RSUs)

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Schedule of Restricted Stock Unit Activity

A summary of the Company’s RSUs is presented below. 

	Number of Shares			Weighted- Average Grant Date Fair Value		Aggregate Intrinsic Value
Non-vested RSUs at January 1, 2019		474,240		$	50.93
Granted		159,831		$	77.74
Vested		(164,913	)	$	43.82
Cancelled		(19,183	)	$	56.18
Non-vested RSUs at December 31, 2019		449,975		$	62.48
Granted		170,411		$	58.27
Vested		(258,307	)	$	54.73
Cancelled		(56,680	)	$	63.46
Non-vested RSUs at December 31, 2020		305,399		$	66.51
Granted		132,757		$	95.68
Vested		(119,203	)	$	66.46
Cancelled		(15,117	)	$	68.53
Non-vested RSUs at December 31, 2021		303,836		$	79.17	$	31,158,382
RSUs expected to vest in the future		277,250		$	78.48	$	28,431,988

Cash Settled RSUs

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Schedule of Restricted Stock Unit Activity

CSRSUs generally have a vesting term of three to four years. A summary of the Company’s CSRSUs is presented below.

	Number of Shares			Weighted- Average Grant Date Fair Value		Aggregate Intrinsic Value
Non-vested CSRSUs at January 1, 2019		337,406		$	47.73
Granted		103,606		$	77.03
Vested		(123,395	)	$	44.61
Cancelled		(21,384	)	$	53.99
Non-vested CSRSUs at December 31, 2019		296,233		$	58.83
Granted		134,259		$	60.30
Vested		(154,653	)	$	49.44
Cancelled		(34,358	)	$	63.03
Non-vested CSRSUs at December 31, 2020		241,481		$	65.06
Granted		52,246		$	89.51
Vested		(104,272	)	$	63.96
Cancelled		(23,195	)	$	69.68
Non-vested CSRSUs at December 31, 2021		166,260		$	72.79	$	17,049,963
CSRSUs expected to vest in the future		149,894		$	72.34	$	15,371,630