Stock-Based Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2023

Stock-Based Compensation Plans

Summary of certain information concerning outstanding and exercisable options

We granted to key employees equity awards consisting of RSUs and PSUs in aggregate amounts as follows:

						RSUs Vesting
						December 1,
						and
			RSU and PSU	Grant Date		PSUs Vesting
	RSUs	PSUs	Aggregate Units	Fair Value		December 31,
2023	109,683	84,129	193,812	$	247.90	2025
2022	192,798	112,451	305,249	$	187.31	2024
2021	191,139	127,356	318,495	$	141.41	2023

Summary of the status of the Company's restricted stock units and changes during the quarter

A summary of the status of our unvested RSUs and PSUs as of December 31, 2023 and changes during the year then ended is as follows:

		Weighted
		Average
	RSU and PSU	Grant Date
	Aggregate Units	Fair Value
Unvested at January 1, 2023	582,012	$	164.60
Granted	193,812		247.90
Vested	(310,485)		146.27
Cancelled or forfeited	(28,100)		187.55
Unvested at December 31, 2023	437,239	$	213.06
Shares reserved for future grants (all plans)	1,539,738