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LEASES - Balance Sheet Amounts Recorded for Operating and Financing Leases (Details) - USD ($) $ in Millions | Dec. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Operating Leases |  |
Operating lease ROU assets, net | $ 1,701 | $ 1,802
Operating lease obligations - current | 250 | 241
Operating lease obligations - non-current | 1,503 | 1,611
Total operating lease obligations | $ 1,754 | $ 1,852
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 | $ 197 | $ 218
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] | Other Liabilities, Current | Other Liabilities, Current
Finance lease obligations - current | $ 16 | $ 17
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Long-Term Debt | Long-Term Debt
Finance lease obligations - non-current | $ 199 | $ 214
Total finance lease obligations | 215 | 231
Assets Subject to Power Purchase Agreement |  |
Operating Leases |  |
Total operating lease obligations | 802 | 941
Alabama Power |  |
Operating Leases |  |
Operating lease ROU assets, net | $ 108 | $ 151
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] | Other Liabilities, Current | Other Liabilities, Current
Operating lease obligations - current | $ 54 | $ 51
Operating lease obligations - non-current | 66 | 119
Total operating lease obligations | $ 121 | $ 170
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 | $ 4 | $ 5
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 | $ 3 | $ 4
Total finance lease obligations | 4 | 5
Alabama Power | Assets Subject to Power Purchase Agreement |  |
Operating Leases |  |
Total operating lease obligations | 104 | 146
Georgia Power |  |
Operating Leases |  |
Operating lease ROU assets, net | 1,157 | 1,308
Operating lease obligations - current | 156 | 151
Operating lease obligations - non-current | 999 | 1,156
Total operating lease obligations | $ 1,155 | $ 1,307
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 | $ 104 | $ 115
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] | Other Liabilities, Current | Other Liabilities, Current
Finance lease obligations - current | $ 10 | $ 9
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Long-Term Debt | Long-Term Debt
Finance lease obligations - non-current | $ 126 | $ 136
Total finance lease obligations | 136 | 145
Georgia Power | Assets Subject to Power Purchase Agreement |  |
Operating Leases |  |
Total operating lease obligations | $ 1,110 | $ 1,250
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 | $ 10 | $ 9
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] | Other Liabilities, Current | Other Liabilities, Current
Operating lease obligations - current | $ 4 | $ 2
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Intangible liabilities included in other deferred credits and liabilities | Intangible liabilities included in other deferred credits and liabilities
Operating lease obligations - non-current | $ 6 | $ 7
Total operating lease obligations | $ 10 | $ 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 | $ 17 | $ 19
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 | $ 17 | $ 18
Total finance lease obligations | 18 | 19
Southern Power |  |
Operating Leases |  |
Operating lease ROU assets, net | $ 479 | $ 415
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] | Other Liabilities, Current | Other Liabilities, Current
Operating lease obligations - current | $ 28 | $ 25
Operating lease obligations - non-current | 497 | 426
Total operating lease obligations | 525 | 451
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 | $ 70 | $ 81
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] | Other Liabilities, Current | Other Liabilities, Current
Operating lease obligations - current | $ 11 | $ 15
Operating lease obligations - non-current | 59 | 67
Total operating lease obligations | 70 | 82
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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