Stock-Based Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement, Noncash Expense [Abstract]

Schedule of Stock Options Roll Forward

A summary of the stock option activity under the Incentive Plan for the year ended December 31, 2021, is presented below:

Stock Options	Number of Stock Options	Weighted Average Exercise Price Per Share		Aggregate Intrinsic Value (1) (in millions)		Weighted Average Remaining Contractual Term (in years)
Outstanding as of December 31, 2020	—	$	—
Granted	778,500	349.17
Exercised	(35,251)	333.94
Forfeited	(37,500)	333.94
Outstanding as of December 31, 2021	705,749	$	350.74	$	237.8	5.7
Exercisable as of December 31, 2021	120,251	$	333.94	$	42.5	4.7
Unvested as of December 31, 2021	585,498	$	354.18	$	195.3	5.9

(1)The intrinsic value of stock options is the amount by which the market price of the stock as of December 31, 2021 exceeded the exercise price of the options.

Schedule of Stock Options Valuation Assumptions

We estimated the fair value of each stock option on the date of grant using a Black-Scholes valuation model with the following assumptions:

Valuation Assumptions	2021
Risk-free interest rate	0.4%	-	0.7%
Expected stock price volatility	37.0%	-	39.0%
Expected life of stock options (in years)	3.0	-	4.5

Summary Of Restricted Stock Units Activity

A summary of the restricted stock unit (“RSU”) activity under the Incentive Plan for the year ended December 31, 2021, is presented below:

Restricted Stock Units	Number of Restricted Stock Units	Weighted Average Grant-Date Fair Value Per Share		Aggregate Intrinsic Value (2) (in millions)		Weighted Average Remaining Contractual Term (in years)
Outstanding as of December 31, 2020	412,602	$	138.65
Granted	7,302	366.07
Converted	(11,416)	190.32
Forfeited	(31,653)	112.39
Outstanding as of December 31, 2021 (1)	376,835	$	143.70	$	259.1	2.5
Vested as of December 31, 2021	366,683	$	136.81	$	252.2	2.3

(1)No RSUs outstanding at December 31, 2021 were convertible to shares of common stock.

(2)The intrinsic value of RSUs is measured by applying the closing stock price as of December 31, 2021 to the applicable number of units.

^[1]

Summary Of Restricted Stock Activity

A summary of the non-vested restricted stock activity under the Incentive Plan for the year ended December 31, 2021 is presented below:

Restricted Stock	Number of Shares	Weighted Average Grant-Date Fair Value Per Share
Non-vested as of December 31, 2020	122,718	$	117.88
Vested	(12,130)	177.77
Forfeited	(109,085)	106.76
Non-vested as of December 31, 2021	1,503	$	441.54

Schedule Of Stock Based Compensation Expense

Stock-based compensation expense consists of the following:

(In millions)	For the Years Ended December 31,
	2021		2020		2019
Stock options	$	33.7	$	—	$	—
Restricted stock units	(1.1)		4.2		4.6
Restricted stock	(7.8)		2.0		3.0
Total	$	24.8	$	6.2	$	7.6

Schedule Of Future Share-Based Compensation Cost

Assuming performance targets are achieved in the periods currently estimated, we expect to recognize the remaining expense for stock-based awards outstanding as of December 31, 2021 over a weighted average period of 1.5 years, as follows:

(In millions)
For the Years Ended December 31,	Stock Options		Restricted Stock Units		Restricted Stock		Total Projected Expense
2022	$	34.8	$	1.0	$	—	$	35.8
2023	34.3		0.7		—		35.0
2024	34.2		0.1		—		34.3
2025	2.5		—		—		2.5
2026	—		—		—		—
Thereafter	—		—		—		—
Total	$	105.8	$	1.8	$	—	$	107.6

[1] The intrinsic value of RSUs is measured by applying the closing stock price as of December 31, 2021 to the applicable number of units.