SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Millions |
12 Months Ended | ||
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Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
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| Allowance for doubtful accounts [Roll Forward] | |||
| Balance at beginning of period | $ 48 | $ 51 | $ 51 |
| Additions charged to costs and expenses | 0 | 1 | 4 |
| Other additions | 0 | 0 | 0 |
| Deductions | 22 | 4 | 4 |
| Balance at end of period | $ 26 | $ 48 | $ 51 |
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
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- Definition Amount of valuation and qualifying accounts and reserves. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of increase in valuation and qualifying accounts and reserves from charge to cost and expense. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of increase in valuation and qualifying accounts and reserves from charge to accounts other than cost and expense. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of decrease in valuation and qualifying accounts and reserves. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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