Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Summary of Stock Options Outstanding and Exercised Under Prior and Existing Stock Incentive Plans

The following is a summary of stock options outstanding and exercised under prior and existing stock incentive plans of the Company:

Year Ended December 31	Stock Options/Shares			Weighted- Average Exercise Price		Weighted-Average Remaining Contractual Term		Aggregate Intrinsic Value (in millions)
2020
Number outstanding at beginning of period		5,718,256		$	39.25
Exercised		(513,293	)		27.48
Cancelled(a)		(24,572	)		45.08
Number outstanding at end of period(b)		5,180,391		$	40.38		3.7	$	32
Exercisable at end of period		4,942,077		$	39.68		3.6	$	34
2019
Number outstanding at beginning of period		9,115,010		$	34.52
Exercised		(3,333,467	)		26.36
Cancelled(a)		(63,287	)		36.74
Number outstanding at end of period(b)		5,718,256		$	39.25		4.4	$	115
Exercisable at end of period		4,869,805		$	37.67		4.0	$	105
2018
Number outstanding at beginning of period		12,668,467		$	32.15
Exercised		(3,443,494	)		25.41
Cancelled(a)		(109,963	)		46.72
Number outstanding at end of period(b)		9,115,010		$	34.52		4.3	$	102
Exercisable at end of period		7,372,036		$	31.61		3.5	$	104

Note: The Company did not grant any stock option awards during 2020, 2019 and 2018.

(a) Options cancelled include both non-vested (i.e., forfeitures) and vested options (i.e., expirations).

(b) Outstanding options include stock-based awards that may be forfeited in future periods. The impact of the estimated forfeitures is reflected in compensation expense.

Summary of Certain Stock Option Activity

The following summarizes certain stock option activity of the Company:

Year Ended December 31 (Dollars in Millions)	2020		2019		2018
Fair value of options vested	$	7	$	10	$	14
Intrinsic value of options exercised		11		95		97
Cash received from options exercised		14		88		87
Tax benefit realized from options exercised		3		24		24

Stock Options Outstanding Additional Information

Additional information regarding stock options outstanding as of December 31, 2020, is as follows:

	Outstanding Options						Exercisable Options
Range of Exercise Prices	Shares		Weighted- Average Remaining Contractual Life (Years)		Weighted- Average Exercise Price		Shares		Weighted- Average Exercise Price
$23.36—$25.00		1,248		.3	$	24.84		1,248	$	24.84
$25.01—$30.00		1,047,197		.8		28.65		1,047,197		28.65
$30.01—$35.00		527,422		2.1		33.98		527,422		33.98
$35.01—$40.00		1,227,889		5.1		39.49		1,227,889		39.49
$40.01—$45.00		1,424,608		3.6		42.42		1,424,608		42.42
$45.01—$50.00		–		–		–		–		–
$50.01—$55.01		952,027		6.1		54.97		713,713		54.97
		5,180,391		3.7	$	40.38		4,942,077	$	39.68

Summary of Company's Restricted Shares of Stock and Unit Awards

A summary of the status of the Company’s restricted shares of stock and unit awards is presented below:

	2020					2019					2018
Year Ended December 31	Shares			Weighted- Average Grant- Date Fair Value		Shares			Weighted- Average Grant- Date Fair Value		Shares			Weighted- Average Grant- Date Fair Value
Outstanding at beginning of period		6,606,833		$	48.99		6,719,298		$	48.17		7,446,955		$	44.49
Granted		3,552,923			53.90		3,519,474			50.45		3,213,023			55.03
Vested		(3,534,770	)		49.28		(3,270,778	)		48.69		(3,373,323	)		46.42
Cancelled		(281,673	)		53.51		(361,161	)		50.55		(567,357	)		49.07
Outstanding at end of period		6,343,313		$	51.38		6,606,833		$	48.99		6,719,298		$	48.17