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LEASES - Balance Sheet Amounts Recorded for Operating and Financing Leases (Details) - USD ($) $ in Millions | Dec. 31, 2023 | Dec. 31, 2022
--- | --- | ---
Operating Leases |  |
Operating lease ROU assets, net | $ 1,432 | $ 1,531
Operating lease obligations - current | 183 | 197
Operating lease obligations - non-current | 1,307 | 1,388
Total operating lease obligations | $ 1,490 | $ 1,585
Finance Leases |  |
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] | Plant in service, net of depreciation | Plant in service, net of depreciation
Finance lease ROU assets, net | $ 272 | $ 292
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] | Other Liabilities, Current | Other Liabilities, Current
Finance lease obligations - current | $ 11 | $ 18
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Long-Term Debt | Long-Term Debt
Finance lease obligations - non-current | $ 287 | $ 296
Total finance lease obligations | 298 | 314
Assets Subject to Power Purchase Agreement |  |
Operating Leases |  |
Total operating lease obligations | 566 | 652
Alabama Power |  |
Operating Leases |  |
Operating lease ROU assets, net | $ 87 | $ 71
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] | Other Liabilities, Current | Other Liabilities, Current
Operating lease obligations - current | $ 12 | $ 9
Operating lease obligations - non-current | 81 | 67
Total operating lease obligations | $ 93 | $ 76
Finance Leases |  |
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] | Plant in service, net of depreciation | Plant in service, net of depreciation
Finance lease ROU assets, net | $ 5 | $ 5
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] | Other Liabilities, Current | Other Liabilities, Current
Finance lease obligations - current | $ 2 | $ 2
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Long-Term Debt | Long-Term Debt
Finance lease obligations - non-current | $ 3 | $ 3
Total finance lease obligations | 5 | 5
Alabama Power | Assets Subject to Power Purchase Agreement |  |
Operating Leases |  |
Total operating lease obligations | 58 | 59
Georgia Power |  |
Operating Leases |  |
Operating lease ROU assets, net | 884 | 1,007
Operating lease obligations - current | 135 | 151
Operating lease obligations - non-current | 740 | 851
Total operating lease obligations | $ 875 | $ 1,002
Finance Leases |  |
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] | Plant in service, net of depreciation | Plant in service, net of depreciation
Finance lease ROU assets, net | $ 203 | $ 205
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] | Other Liabilities, Current | Other Liabilities, Current
Finance lease obligations - current | $ 18 | $ 16
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Long-Term Debt | Long-Term Debt
Finance lease obligations - non-current | $ 222 | $ 222
Total finance lease obligations | 240 | 238
Georgia Power | Assets Subject to Power Purchase Agreement |  |
Operating Leases |  |
Total operating lease obligations | $ 813 | $ 952
Mississippi Power |  |
Operating Leases |  |
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] | Other Assets, Noncurrent | Other Assets, Noncurrent
Operating lease ROU assets, net | $ 9 | $ 9
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] | Other Liabilities, Current | Other Liabilities, Current
Operating lease obligations - current | $ 3 | $ 4
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Other Liabilities, Noncurrent | Other Liabilities, Noncurrent
Operating lease obligations - non-current | $ 6 | $ 5
Total operating lease obligations | $ 9 | $ 9
Finance Leases |  |
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] | Plant in service, net of depreciation | Plant in service, net of depreciation
Finance lease ROU assets, net | $ 15 | $ 16
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] | Other Liabilities, Current | Other Liabilities, Current
Finance lease obligations - current | $ 1 | $ 1
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Long-Term Debt | Long-Term Debt
Finance lease obligations - non-current | $ 15 | $ 16
Total finance lease obligations | 16 | 17
Southern Power |  |
Operating Leases |  |
Operating lease ROU assets, net | $ 488 | $ 489
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] | Other Liabilities, Current | Other Liabilities, Current
Operating lease obligations - current | $ 29 | $ 28
Operating lease obligations - non-current | 517 | 514
Total operating lease obligations | 546 | 542
Finance Leases |  |
Finance lease ROU assets, net | 0 | 0
Finance lease obligations - current | 0 | 0
Finance lease obligations - non-current | 0 | 0
Total finance lease obligations | 0 | 0
Southern Company Gas |  |
Operating Leases |  |
Operating lease ROU assets, net | $ 47 | $ 57
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] | Other Liabilities, Current | Other Liabilities, Current
Operating lease obligations - current | $ 11 | $ 9
Operating lease obligations - non-current | 40 | 51
Total operating lease obligations | 51 | 60
Finance Leases |  |
Finance lease ROU assets, net | 0 | 0
Finance lease obligations - current | 0 | 0
Finance lease obligations - non-current | 0 | 0
Total finance lease obligations | $ 0 | $ 0

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