Stock Based Compensation Plans (Tables)

6 Months Ended

Jun. 30, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Option Activity

The following table provides a summary of option activity:

						Weighted
						Average
				Weighted		Remaining
				Average		Contractual		Aggregate
				Exercise		Term		Intrinsic
	Options			Price		(in Years)		Value
Outstanding at December 31, 2020		12.7		$	50.72
Granted		1.4			84.69
Exercised		(0.3	)		33.94
Outstanding at June 30, 2021		13.8		$	54.69		5.8	$	419.3
Exercisable at June 30, 2021		8.9		$	42.17		4.2	$	384.5

Information Regarding Intrinsic Value of Stock Options Exercised and Stock Compensation Expense Related to Stock Option Awards

The following table provides information regarding the intrinsic value of stock options exercised and stock compensation expense related to stock option awards:  

	Three Months Ended				Six Months Ended
	June 30,		June 30,		June 30,		June 30,
	2021		2020		2021		2020
Intrinsic Value of Stock Options Exercised	$	9.3	$	54.6	$	18.8	$	68.9
Stock Compensation Expense Related to Stock Option Awards	$	13.4	$	12.7	$	16.5	$	15.4
Issued Stock Options		1.4		1.8		1.4		1.8
Weighted Average Fair Value of Stock Options issued (per share)	$	17.34	$	12.74	$	17.31	$	12.73
Fair Value of Stock Options Issued	$	24.6	$	23.1	$	25.1	$	23.6

Assumptions Used in Valuation of Issued Stock Options

The following table provides a summary of the assumptions used in the valuation of issued stock options:

	Three Months Ended						Six Months Ended
	June 30,			June 30,			June 30,			June 30,
	2021			2020			2021			2020
Risk-free interest rate		1.4	%		0.5	%		1.3	%		0.5	%
Expected life in years		7.2			7.3			7.2			7.3
Expected volatility		20.7	%		19.9	%		20.7	%		19.8	%
Dividend yield		1.2	%		1.3	%		1.2	%		1.3	%