1.0.0.3 true Consolidated Statements of Common Stockholders Equity (USD $) In Millions, except Share data in Thousands false 1 $ true false false false Common Stock us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_CommonStockMember us-gaap_StatementEquityComponentsAxis explicitMember Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 2 $ true false false false Additional Paid In Capital us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_AdditionalPaidInCapitalMember us-gaap_StatementEquityComponentsAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 3 $ true false false false Treasury Stock us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_TreasuryStockMember us-gaap_StatementEquityComponentsAxis explicitMember Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 4 $ true false false false Retained Earnings us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_RetainedEarningsMember us-gaap_StatementEquityComponentsAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 5 $ true false false false Accumulated Other Comprehensive Income us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_AccumulatedOtherComprehensiveIncomeMember us-gaap_StatementEquityComponentsAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 6 $ true false false false Preferred and Preference Stock of Subsidiaries us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_NoncontrollingInterestMember us-gaap_StatementEquityComponentsAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 7 $ false false Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDEPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 6 Beginning Balance, shares at Dec. 31, 2006 3 us-gaap_SharesIssued us-gaap true na instant shares No definition available. false false false true false false true false false 1 false true 751864000 751864 true false 2 false false 0 0 true false 3 false true -5594000 -5594 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false false 0 0 false false No definition available. No authoritative reference available. false 5 Beginning Balance at Dec. 31, 2006 3 us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap true credit instant monetary No definition available. false false false true false false true false false 1 true true 3759000000 3759 true false 2 true true 1096000000 1096 true false 3 true true -192000000 -192 true false 4 true true 6765000000 6765 true false 5 true true -57000000 -57 true false 6 true true 246000000 246 true false 7 true true 11617000000 11617 false false No definition available. No authoritative reference available. false 7 Net income after dividends on preferred and preference stock of subsidiaries 3 us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false true 1734000000 1734 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false true 1734000000 1734 false false No definition available. No authoritative reference available. false 8 Other comprehensive income 3 us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false true 27000000 27 true false 6 false false 0 0 true false 7 false true 27000000 27 false false No definition available. No authoritative reference available. false 9 Cumulative effect of new accounting standards 3 us-gaap_CumulativeEffectOfInitialAdoptionOfNewAccountingPrinciple us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false true -140000000 -140 [1] true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false true -140000000 -140 [1] false false No definition available. No authoritative reference available. false 10 Stock issued 3 us-gaap_StockIssuedDuringPeriodValueNewIssues us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 58000000 58 true false 2 false true 356000000 356 true false 3 false true 183000000 183 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false true 461000000 461 true false 7 false true 1058000000 1058 false false No definition available. No authoritative reference available. false 11 Stock issued, shares 3 us-gaap_StockIssuedDuringPeriodSharesNewIssues us-gaap true na duration shares No definition available. false false false false false false false false false 1 false true 11639000 11639 true false 2 false false 0 0 true false 3 false true 5255000 5255 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false false 0 0 false false No definition available. No authoritative reference available. false 12 Cash dividends 3 us-gaap_DividendsCommonStockCash us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false true -1204000000 -1204 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false true -1204000000 -1204 false false No definition available. No authoritative reference available. false 13 Other 3 us-gaap_StockholdersEquityOther us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false true 2000000 2 true false 3 false true -2000000 -2 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false true 0 0 false false No definition available. No authoritative reference available. true 14 Other, shares 3 us-gaap_TreasuryStockSharesAcquired us-gaap true na duration shares No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false true -60000 -60 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false false 0 0 false false No definition available. No authoritative reference available. true 15 Ending Balance at Dec. 31, 2007 3 us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap true credit instant monetary No definition available. false false false true false false false true false 1 false true 3817000000 3817 true false 2 false true 1454000000 1454 true false 3 false true -11000000 -11 true false 4 false true 7155000000 7155 true false 5 false true -30000000 -30 true false 6 false true 707000000 707 true false 7 false true 13092000000 13092 false false No definition available. No authoritative reference available. false 16 Ending Balance, shares at Dec. 31, 2007 3 us-gaap_SharesIssued us-gaap true na instant shares No definition available. false false false true false false false true false 1 false true 763503000 763503 true false 2 false false 0 0 true false 3 false true -399000 -399 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false false 0 0 false false No definition available. No authoritative reference available. false 7 Net income after dividends on preferred and preference stock of subsidiaries 3 us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false true 1742000000 1742 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false true 1742000000 1742 false false No definition available. No authoritative reference available. false 8 Other comprehensive income 3 us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false true -75000000 -75 true false 6 false false 0 0 true false 7 false true -75000000 -75 false false No definition available. No authoritative reference available. false 10 Stock issued 3 us-gaap_StockIssuedDuringPeriodValueNewIssues us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 71000000 71 true false 2 false true 438000000 438 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false true 509000000 509 false false No definition available. No authoritative reference available. false 11 Stock issued, shares 3 us-gaap_StockIssuedDuringPeriodSharesNewIssues us-gaap true na duration shares No definition available. false false false false false false false false false 1 false true 14113000 14113 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false false 0 0 false false No definition available. No authoritative reference available. false 12 Cash dividends 3 us-gaap_DividendsCommonStockCash us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false true -1279000000 -1279 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false true -1279000000 -1279 false false No definition available. No authoritative reference available. false 13 Other 3 us-gaap_StockholdersEquityOther us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false true 1000000 1 true false 3 false true -1000000 -1 true false 4 false true -6000000 -6 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false true -6000000 -6 false false No definition available. No authoritative reference available. true 14 Other, shares 3 us-gaap_TreasuryStockSharesAcquired us-gaap true na duration shares No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false true -25000 -25 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false false 0 0 false false No definition available. No authoritative reference available. true 15 Ending Balance at Dec. 31, 2008 3 us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap true credit instant monetary No definition available. false false false true false false false true false 1 false true 3888000000 3888 true false 2 false true 1893000000 1893 true false 3 false true -12000000 -12 true false 4 false true 7612000000 7612 true false 5 false true -105000000 -105 true false 6 false true 707000000 707 true false 7 false true 13983000000 13983 false false No definition available. No authoritative reference available. false 16 Ending Balance, shares at Dec. 31, 2008 3 us-gaap_SharesIssued us-gaap true na instant shares No definition available. false false false true false false false true false 1 false true 777616000 777616 true false 2 false false 0 0 true false 3 false true -424000 -424 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false false 0 0 false false No definition available. No authoritative reference available. false 7 Net income after dividends on preferred and preference stock of subsidiaries 3 us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false true 1643000000 1643 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false true 1643000000 1643 false false No definition available. No authoritative reference available. false 8 Other comprehensive income 3 us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false true 17000000 17 true false 6 false false 0 0 true false 7 false true 17000000 17 false false No definition available. No authoritative reference available. false 10 Stock issued 3 us-gaap_StockIssuedDuringPeriodValueNewIssues us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 213000000 213 true false 2 false true 1100000000 1100 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false true 1313000000 1313 false false No definition available. No authoritative reference available. false 11 Stock issued, shares 3 us-gaap_StockIssuedDuringPeriodSharesNewIssues us-gaap true na duration shares No definition available. false false false false false false false false false 1 false true 42536000 42536 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false false 0 0 false false No definition available. No authoritative reference available. false 12 Cash dividends 3 us-gaap_DividendsCommonStockCash us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false true -1369000000 -1369 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false true -1369000000 -1369 false false No definition available. No authoritative reference available. false 13 Other 3 us-gaap_StockholdersEquityOther us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false true 2000000 2 true false 3 false true -3000000 -3 true false 4 false true -1000000 -1 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false true -2000000 -2 false false No definition available. No authoritative reference available. true 14 Other, shares 3 us-gaap_TreasuryStockSharesAcquired us-gaap true na duration shares No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false true -81000 -81 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false false 0 0 false false No definition available. No authoritative reference available. true 15 Ending Balance at Dec. 31, 2009 3 us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap true credit instant monetary No definition available. false false false true false false false true false 1 true true 4101000000 4101 true false 2 true true 2995000000 2995 true false 3 true true -15000000 -15 true false 4 true true 7885000000 7885 true false 5 true true -88000000 -88 true false 6 true true 707000000 707 true false 7 true true 15585000000 15585 false false No definition available. No authoritative reference available. false 16 Ending Balance, shares at Dec. 31, 2009 3 us-gaap_SharesIssued us-gaap true na instant shares No definition available. false false false true false false false true false 1 false true 820152000 820152 true false 2 false false 0 0 true false 3 false true -505000 -505 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false false 0 0 true false 7 false false 0 0 false false No definition available. No authoritative reference available. false 1 In 2007 Southern Company recorded two adjustments net of tax in respect of new accounting guidance; a $125 million adjustment in respect of leverage lease transactions and a $15 million adjustment in respect of uncertain tax positions. false 7 30 false Millions Thousands UnKnown false true