Note 4 - Stock-based Compensation (Tables)

6 Months Ended

Jun. 30, 2022

Notes Tables

Share-Based Payment Arrangement, Cost by Plan [Table Text Block]

	Three Months Ended				Six Months Ended
	June 30,				June 30,
Millions	2022		2021		2022		2021
Stock-based compensation, before tax:
Stock options	$	3	$	4	$	7	$	8
Retention awards		19		18		41		34
ESPP		4		-		8		-
Total stock-based compensation, before tax	$	26	$	22	$	56	$	42
Excess tax benefits from equity compensation plans	$	1	$	2	$	18	$	17

Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

Weighted-Average Assumptions	2022			2021
Risk-free interest rate		1.6	%		0.4	%
Dividend yield		1.9	%		1.9	%
Expected life (years)		4.4			4.6
Volatility		28.7	%		28.3	%
Weighted-average grant-date fair value of options granted	$	51.92		$	39.97

Share-Based Payment Arrangement, Option, Activity [Table Text Block]

	Options (thous.)		Weighted-Average Exercise Price			Weighted-Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (millions)
Outstanding at January 1, 2022		2,106		$	149.84		6.3		$	215
Granted		328			244.35		N/A			N/A
Exercised		(339	)		127.62		N/A			N/A
Forfeited or expired		(25	)		211.39		N/A			N/A
Outstanding at June 30, 2022		2,070		$	167.71		6.5		$	104
Vested or expected to vest at June 30, 2022		2,049		$	167.17		6.4		$	104
Options exercisable at June 30, 2022		1,390		$	142.20		5.3		$	99

Cash Proceeds Received and Tax Benefit from Share-Based Payment Awards [Table Text Block]

	Three Months Ended					Six Months Ended
	June 30,					June 30,
Millions	2022		2021			2022			2021
Intrinsic value of stock options exercised	$	2	$	9		$	44		$	32
Cash received from option exercises		2		4			17			34
Treasury shares repurchased for employee payroll taxes		-		(1	)		(5	)		(7	)
Tax benefit realized from option exercises		1		2			6			6
Aggregate grant-date fair value of stock options vested		-		-			13			14

Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]

	Shares (thous.)		Weighted-Average Grant-Date Fair Value
Nonvested at January 1, 2022		1,287		$	165.10
Granted		234			244.27
Vested		(408	)		125.98
Forfeited		(36	)		190.72
Nonvested at June 30, 2022		1,077		$	196.26

Schedule of Nonvested Performance-Based Units Activity [Table Text Block]

	Shares (thous.)		Weighted-Average Grant-Date Fair Value
Nonvested at January 1, 2022		641		$	173.03
Granted		209			244.35
Vested		(56	)		162.64
Unearned		(163	)		161.57
Forfeited		(21	)		207.64
Nonvested at June 30, 2022		610		$	200.29