FAIR VALUE MEASUREMENTS (Tables)

6 Months Ended

Jun. 30, 2022

Fair Value Disclosures [Abstract]

Investments Classified by Contractual Maturity Date

Maturities for marketable securities (in millions):

June 30, 2022	Cost Basis		Fair Value
Due in one year or less	$	803	$	799
Due after one year through five years	1,895		1,818
Due after five years	27		24
Total	$	2,725	$	2,641

As of June 30, 2022, $6 million of total marketable securities do not have a maturity date and are therefore excluded from the total fair value of maturities for marketable securities above.

Fair Value, by Balance Sheet Grouping

Fair values of financial instruments on the condensed consolidated balance sheet (in millions):

	June 30, 2022						December 31, 2021
	Level 1		Level 2		Total		Level 1		Level 2		Total
Assets
Marketable securities
U.S. government and agency securities	$	522	$	—	$	522	$	331	$	—	$	331
Equity mutual funds	5		—		5		6		—		6
Foreign government bonds	—		28		28		—		38		38
Asset-backed securities	—		278		278		—		311		311
Mortgage-backed securities	—		218		218		—		232		232
Corporate notes and bonds	—		1,549		1,549		—		1,663		1,663
Municipal securities	—		47		47		—		65		65
Total Marketable securities	527		2,120		2,647		337		2,309		2,646
Derivative instruments
Fuel hedge - call options	—		175		175		—		81		81
Interest rate swap agreements	—		9		9		—		—		—
Total Assets	$	527	$	2,304	$	2,831	$	337	$	2,390	$	2,727
Liabilities
Derivative instruments
Interest rate swap agreements	—		—		—		—		(9)		(9)
Total Liabilities	$	—	$	—	$	—	$	—	$	(9)	$	(9)

Fixed-rate debt on the condensed consolidated balance sheet and the estimated fair value of long-term fixed-rate debt is as follows (in millions):

	June 30, 2022		December 31, 2021
Total fixed-rate debt	$	1,731	$	1,821
Estimated fair value	$	1,711	$	1,919