XML 54 R27.htm IDEA: XBRL DOCUMENT
v3.20.4

FAIR VALUE MEASUREMENTS (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2020
Fair Value Disclosures [Abstract] |
Fair Value, by Balance Sheet Grouping [Table Text Block] | Fair values of financial instruments on the consolidated balance sheet (in millions):
| December 31, 2020 |  | December 31, 2019
| Level 1 |  | Level 2 |  | Total |  | Level 1 |  | Level 2 |  | Total
Assets |  |  |  |  |  |  |  |  |  |  |
Marketable securities |  |  |  |  |  |  |  |  |  |  |
U.S. government and agency securities | $ | 407 |  |  | $ | — |  |  | $ | 407 |  |  | $ | 330 |  |  | $ | — |  |  | $ | 330 |
Equity mutual funds | 7 |  |  | — |  |  | 7 |  |  | 6 |  |  | — |  |  | 6 |
Foreign government bonds | — |  |  | 20 |  |  | 20 |  |  | — |  |  | 31 |  |  | 31 |
Asset-backed securities | — |  |  | 224 |  |  | 224 |  |  | — |  |  | 211 |  |  | 211 |
Mortgage-backed securities | — |  |  | 290 |  |  | 290 |  |  | — |  |  | 176 |  |  | 176 |
Corporate notes and bonds | — |  |  | 978 |  |  | 978 |  |  | — |  |  | 523 |  |  | 523 |
Municipal securities | — |  |  | 50 |  |  | 50 |  |  | — |  |  | 23 |  |  | 23 |
Total Marketable securities | 414 |  |  | 1,562 |  |  | 1,976 |  |  | 336 |  |  | 964 |  |  | 1,300
Derivative instruments |  |  |  |  |  |  |  |  |  |  |
Fuel hedge contracts - call options | — |  |  | 15 |  |  | 15 |  |  | — |  |  | 11 |  |  | 11 |
Interest rate swap agreements | — |  |  | — |  |  | — |  |  | — |  |  | 3 |  |  | 3 |
Total Assets | $ | 414 |  |  | $ | 1,577 |  |  | $ | 1,991 |  |  | $ | 336 |  |  | $ | 978 |  |  | $ | 1,314 |
Liabilities |  |  |  |  |  |  |  |  |  |  |
Derivative instruments |  |  |  |  |  |  |  |  |  |  |
Interest rate swap agreements | — |  |  | (25) |  |  | (25) |  |  | — |  |  | (10) |  |  | (10) |
Total Liabilities | $ | — |  |  | $ | (25) |  |  | $ | (25) |  |  | $ | — |  |  | $ | (10) |  |  | $ | (10) |
Fixed-rate debt on the consolidated balance sheet and the estimated fair value of long-term fixed-rate debt (in millions):
| December 31, 2020 |  | December 31, 2019
Total fixed rate debt | $ | 1,662 |  |  | $ | 475 |
Estimated fair value | $ | 1,778 |  |  | $ | 483 |
Schedule of Realized Gain (Loss) [Table Text Block] | Proceeds from sales of marketable securities were $2.3 billion, $1.7 billion and $1.1 billion in 2020, 2019, and 2018.
Schedule of Debt Investment Maturities [Table Text Block] | Maturities for marketable securities (in millions):
December 31, 2020 | Cost Basis |  | Fair Value
Due in one year or less | $ | 775 |  |  | $ | 777 |
Due after one year through five years | 1,146 |  |  | 1,175 |
Due after five years through 10 years | 23 |  |  | 24 |
Total | $ | 1,944 |  |  | $ | 1,976 |

X
- Definition Tabular disclosure of the fair value of financial instruments, including financial assets and financial liabilities, and the measurements of those instruments, assets, and liabilities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13467-108611 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueByBalanceSheetGroupingTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_FairValueDisclosuresAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of maturities of an entity's investments as well as any other information pertinent to the investments. + References No definition available. + Details
Name: | us-gaap_InvestmentsClassifiedByContractualMaturityDateTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the proceeds from sales of available-for-sale securities and the gross realized gains and gross realized losses that have been included in earnings as a result of those sales. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27357-111563 + Details
Name: | us-gaap_ScheduleOfRealizedGainLossTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration