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Schedule II - Valuation and Qualifying Accounts and Reserves (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Allowance for uncollectible accounts |  |  |
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] |  |  |
Balance at Beginning of Period | $ 20 | $ 20 | $ 24
Charged to Expense | 29 | 29 | 29
Charged to Other Accounts | 0 | 0 | 0
Deductions | 29 | 29 | 33
Balance at End of Period | 20 | 20 | 20
Allowance for uncollectible accounts | Consumers Energy Company |  |  |
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] |  |  |
Balance at Beginning of Period | 20 | 20 | 24
Charged to Expense | 29 | 29 | 29
Charged to Other Accounts | 0 | 0 | 0
Deductions | 29 | 29 | 33
Balance at End of Period | 20 | 20 | 20
Deferred tax valuation allowance |  |  |
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] |  |  |
Balance at Beginning of Period | 8 | 15 | 5
Charged to Expense | 0 | 2 | 10
Charged to Other Accounts | 0 | 0 | 0
Deductions | 6 | 9 | 0
Balance at End of Period | 2 | 8 | 15
Allowance for notes receivable |  |  |
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] |  |  |
Balance at Beginning of Period | 24 | 20 | 16
Charged to Expense | 38 | 25 | 20
Charged to Other Accounts | 0 | 0 | 0
Deductions | 29 | 21 | 16
Balance at End of Period | $ 33 | $ 24 | $ 20

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- Definition Amount of valuation and qualifying accounts and reserves. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690 + Details
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