Incentive Plans (Tables)

12 Months Ended

Dec. 31, 2019

Share-based Payment Arrangement [Abstract]

Defined Contribution Plan Disclosures

The Company match for the deferred compensation plan is as follows:

	Year Ended December 31,
	2019		2018		2017
	(in millions)
Deferred compensation plan	$	2	$	3	$	3

The Company match for the 401(k) plan is as follows:

	Year Ended December 31,
	2019		2018		2017
	(in millions)
401(k) plan	$	27	$	36	$	25

Number of LTIP shares available for issuance

The number of shares available for grant pursuant to awards under the LTIP is as follows:

	As of December 31, 2019
Approved and authorized awards	12,600,000
Awards granted under plan	(8,371,882)
Awards available for future grant	4,228,118

Number of ESPP shares available for issuance

The number of shares available for issuance under the ESPP is as follows:

	As of December 31, 2019
Approved and authorized shares	1,250,000
Shares issued	(1,056,938)
Shares available for future issuance	193,062

Schedule of stock-based compensation expense

Stock-based compensation expense and the associated income tax benefit for awards issued under both the LTIP and ESPP are as follows:

	Year Ended December 31,
	2019		2018		2017
	(in millions)
Restricted stock - Equity Awards	$	79	$	65	$	60
Restricted stock - Liability Awards	19		17		24
Performance unit awards	19		18		17
Employee stock purchase plan	2		2		2
Total stock-based compensation expense	$	119	$	102	$	103
Income tax benefit	$	18	$	17	$	19

Schedule of restricted stock award activity

Restricted stock award activity is as follows:

	Year Ended December 31, 2019
	Equity Awards			Liability Awards
	Number of Shares	Weighted Average Grant- Date Fair Value		Number of shares
Beginning incentive compensation awards	799,672	$	165.10	201,501
Awards granted	713,238	$	137.23	221,497
Awards forfeited	(49,873)	$	147.06	(32,316)
Awards vested	(638,844)	$	154.89	(143,831)
Ending incentive compensation awards	824,193	$	149.99	246,851

Schedule of assumptions to estimate the fair value

Assumptions used to estimate the fair value of performance unit awards granted in each of the following years are as follows: 

	2019				2018				2017
Risk-free interest rate	2.49%				2.41%				1.42%
Range of volatilities	27.7	%	-	43.4%	30.4	%	-	53.3%	33.6	%	-	58.2%

Schedule of performance unit activity

Performance unit activity is as follows:

	Year Ended December 31, 2019
	Number of Units (a)	Weighted Average Grant-Date Fair Value
Beginning performance unit awards	119,169	$	251.92
Units granted	86,483	$	165.84
Units vested (b)	(89,437)	$	247.10
Ending performance unit awards	116,215	$	191.58

_____________________

(a)Amount reflects the number of performance units initially granted. The actual payout of shares upon vesting may be between zero and 250 percent of the performance units included in this table depending upon the total shareholder return ranking of the Company compared to peer companies at the vesting date.

(b)Amount reflects the number of performance units vested upon retirement of eligible officers and the vesting of performance units for which the service period has ended. On December 31, 2019, the service period lapsed on 58,539 performance unit awards that earned 1.00 shares for each vested award. The 58,539 aggregate shares of common stock were issued on January 2, 2020. Of the 58,539 shares of common stock issued, 1,911 shares were associated with units that vested in prior years associated with the retirement of an eligible officer. In addition, 32,809 units vested upon retirement of eligible officers and will be issued when the performance period ends in 2020 and 2021.

Grant-date Fair Value of Vested Performance Units

The grant-date fair value of vested performance units is as follows:

	Year Ended December 31,
	2019		2018		2017
	(in millions)
Grant-date fair value of vested performance units	$	22	$	21	$	18

Cash Paid for Awards

Cash paid for vested Liability Awards is as follows:

	Year Ended December 31,
	2019		2018		2017
	(in millions)
Cash paid for vested Liability Awards	$	20	$	24	$	20