Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement [Abstract]

Allocation of Share-based Compensation Costs by Plan

The following table summarizes our stock-based compensation expense recorded within selling, general and administrative expenses for the years ended December 31:

($ in millions)	2021		2020		2019
Stock option and appreciation rights	$	12.5	$	10.2	$	9.1
Performance share units, stock-settled	17.6		16.6		9.5
Performance share units, cash-settled	1.0		0.4		0.1
Performance share units, dividend equivalents	0.2		0.6		0.2
Employee stock purchase plan	1.4		1.1		0.9
Deferred compensation plans and restricted share awards	4.8		5.1		4.6
Total stock-based compensation expense	$	37.5	$	34.0	$	24.4

Schedule of Stock Options Activity

The following table summarizes changes in outstanding options:

(in millions, except per share data)	2021	2020	2019
Options outstanding, January 1	2.4	2.7	3.0
Granted	0.1	0.2	0.3
Exercised	(0.5)	(0.5)	(0.6)
Forfeited	—	—	—
Options outstanding, December 31	2.0	2.4	2.7
Options exercisable, December 31	1.5	1.6	1.6

Weighted Average Exercise Price	2021		2020		2019
Options outstanding, January 1	$	81.37	$	67.02	$	58.93
Granted	280.22		178.11		103.40
Exercised	60.63		49.99		46.42
Forfeited	134.89		103.51		92.71
Options outstanding, December 31	$	101.73	$	81.37	$	67.02
Options exercisable, December 31	$	73.46	$	62.42	$	53.12

Schedule of Stock Appreciation Rights Award Activity

The following table summarizes changes in outstanding SARs:

	2021	2020	2019
SARs outstanding, January 1	27,679	35,993	39,819
Granted	704	3,272	3,364
Exercised	(6,029)	(11,261)	(6,790)
Forfeited	(1,300)	(325)	(400)
SARs outstanding, December 31	21,054	27,679	35,993
SARs exercisable, December 31	16,644	27,182	27,781

Weighted Average Exercise Price	2021		2020		2019
SARs outstanding, January 1	$	75.43	$	52.36	$	46.48
Granted	319.94		190.97		102.51
Exercised	48.62		35.37		42.08
Forfeited	125.36		71.43		63.43
SARs outstanding, December 31	$	88.18	$	75.43	$	52.36
SARs exercisable, December 31	$	64.61	$	40.23	$	40.73

Schedule of Nonvested Performance-based Share Activity

The following table summarizes changes in our outstanding stock-settled PSU awards:

	2021		2020		2019
Non-vested stock-settled PSU awards, January 1	222,799		264,622		296,037
Granted at target level	37,701		53,659		84,309
Adjustments above/(below) target	50,965		(14,004)		(50,556)
Vested and converted	(143,465)		(70,074)		(48,964)
Forfeited	(3,526)		(11,404)		(16,204)
Non-vested stock-settled PSU awards, December 31	164,474		222,799		264,622
Weighted Average Fair Value	2021		2020		2019
Non-vested stock-settled PSU awards, January 1	$	116.37	$	92.80	$	76.84
Granted at target level	333.58		177.31		103.40
Adjustments above/(below) target	93.38		77.02		83.89
Vested and converted	272.65		173.22		102.51
Forfeited	152.30		104.43		69.09
Non-vested stock-settled PSU awards, December 31	$	179.88	$	116.37	$	92.80

Schedule of Nonvested Performance-based Units Activity

The following table summarizes changes in our outstanding cash-settled PSU awards:

	2021	2020	2019
Non-vested cash-settled PSU awards, January 1	2,112	1,981	1,592
Granted at target level	163	732	806
Adjustments above/(below) target	311	(99)	(206)
Vested and converted	(877)	(502)	(211)
Forfeited	(391)	—	—
Non-vested cash-settled PSU awards, December 31	1,318	2,112	1,981

Weighted Average Fair Value	2021		2020		2019
Non-vested cash-settled PSU awards, January 1	$	130.13	$	93.28	$	79.48
Granted at target level	320.12		190.71		102.51
Adjustments above/(below) target	91.40		74.43		56.95
Vested and converted	274.29		173.22		102.51
Forfeited	135.64		—		—
Non-vested cash-settled PSU awards, December 31	$	169.53	$	130.13	$	93.28