Stock-based Compensation Expense (Tables)

12 Months Ended

Dec. 31, 2022

Share-Based Payment Arrangement [Abstract]

Schedule of Weighted Average Assumptions used in the Black-Scholes Option Pricing Model

The weighted average assumptions used in the Black-Scholes option pricing model are as follows: 

	2022		2021		2020
Expected stock price volatility	26	%	26	%	22	%
Risk free interest rate	2.0	%	0.8	%	1.1	%
Expected life of options (years)	4.7		4.3		4.3
Expected annual dividend	0.2	%	0.2	%	0.3	%

Summary of the Company's Option Activity

A summary of the company’s option activity for the year ended December 31, 2022 is presented below:

	Shares (in millions)	Weighted average exercise price		Weighted average remaining contractual term (in years)	Aggregate intrinsic value (in millions)
Outstanding at December 31, 2021	6.0	$	319.95
Granted	0.8	530.48
Exercised	(0.9)	199.85
Canceled/expired	(0.3)	503.76
Outstanding at December 31, 2022	5.6	$	359.27	4.2	$	1,125
Vested and unvested expected to vest at December 31, 2022	5.3	$	351.97	4.7	$	1,114
Exercisable at December 31, 2022	2.9	$	251.44	2.8	$	891

Summary of the Company's Restricted Unit Activity

A summary of the company’s restricted unit activity for the year ended December 31, 2022 is presented below:

	Units (in millions)	Weighted average grant-date fair value
Unvested at December 31, 2021	0.8	$	425.39
Granted	0.4	520.83
Vested	(0.4)	375.77
Forfeited	(0.1)	510.37
Unvested at December 31, 2022	0.7	$	495.39