$UNM
Unum Group Stock $unm

$unm Overview Financials Valuation SEC Filings Company Website

2021 Q3 Form 10-Q Financial Statement

#000000551321000135 Filed on August 04, 2021

Income Statement

Concept	2021 Q3	2021 Q2	2020 Q2
Revenue	$2.970B	$2.993B	$3.021B
YoY Change	-0.89%	-0.93%	0.15%
Cost Of Revenue	$1.754B	$1.854B	$1.883B
YoY Change	-7.13%	-1.52%	-1.04%
Gross Profit	$1.216B	$1.139B	$1.138B
YoY Change	9.76%	0.04%	2.18%
Gross Profit Margin	40.94%	38.05%	37.68%
Selling, General & Admin	$241.6M	$247.4M	$233.2M
YoY Change	5.04%	6.09%	4.15%
% of Gross Profit	19.87%	21.72%	20.48%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$30.40M	$136.0M	$140.7M
YoY Change	-79.69%	-3.34%	-7.19%
% of Gross Profit	2.5%	11.94%	12.36%
Operating Expenses	$2.515B	$2.604B	$2.636B
YoY Change	-4.15%	-1.22%	0.53%
Operating Profit	-$1.299B	-$1.465B	-$1.498B
YoY Change	-14.31%	-2.18%	-0.68%
Interest Expense	-$44.70M	-$45.30M	-$47.50M
YoY Change	-9.51%	-4.63%	11.5%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$409.9M	$262.6M	$337.6M
YoY Change	36.82%	-22.22%	-4.09%
Income Tax	$81.30M	$79.70M	$72.10M
% Of Pretax Income	19.83%	30.35%	21.36%
Net Earnings	$328.6M	$182.9M	$265.5M
YoY Change	42.19%	-31.11%	-5.58%
Net Earnings / Revenue	11.07%	6.11%	8.79%
Basic Earnings Per Share	$1.61	$0.89	$1.30
Diluted Earnings Per Share	$1.602M	$0.89	$1.30
COMMON SHARES
Basic Shares Outstanding	204.4M shares	204.5M shares	203.6M shares
Diluted Shares Outstanding	205.1M shares	205.3M shares	203.7M shares

Balance Sheet

Concept	2021 Q3	2021 Q2	2020 Q2
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$121.7M	$123.1M	$165.6M
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$462.5M	$499.8M	$518.1M
YoY Change	-9.1%	-3.53%	-6.83%
Goodwill		$353.3M	$348.9M
YoY Change		1.26%	-0.34%
Intangibles
YoY Change
Long-Term Investments	$52.42B	$52.17B	$57.89B
YoY Change	-10.19%	-9.88%	6.48%
Other Assets
YoY Change
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$70.60B	$70.81B	$69.31B
YoY Change	1.41%	2.17%	5.26%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due			$399.9M
YoY Change
Total Short-Term Liabilities	$40.70M	$69.00M	$969.0M
YoY Change	-91.15%	-92.88%	287.6%
LONG-TERM LIABILITIES
Long-Term Debt	$3.441B	$3.441B	$3.393B
YoY Change	1.85%	1.43%	1.56%
Other Long-Term Liabilities	$2.999B	$2.890B	$2.022B
YoY Change	50.12%	42.93%	10.67%
Total Long-Term Liabilities	$6.441B	$6.332B	$5.415B
YoY Change	19.78%	16.93%	4.78%
TOTAL LIABILITIES
Total Short-Term Liabilities	$40.70M	$69.00M	$969.0M
Total Long-Term Liabilities	$6.441B	$6.332B	$5.415B
Total Liabilities	$59.48B	$59.86B	$58.74B
YoY Change	1.29%	1.9%	4.17%
SHAREHOLDERS EQUITY
Retained Earnings		$11.49B	$11.02B
YoY Change		4.25%	6.89%
Common Stock		$2.418B	$2.395B
YoY Change		0.95%	1.2%
Preferred Stock
YoY Change
Treasury Stock (at cost)		$3.180B	$3.180B
YoY Change		0.0%	6.72%
Treasury Stock Shares		102.9M shares	102.9M shares
Shareholders Equity	$11.12B	$10.95B	$10.56B
YoY Change
Total Liabilities & Shareholders Equity	$70.60B	$70.81B	$69.31B
YoY Change	1.41%	2.17%	5.26%

Cashflow Statement

Concept	2021 Q3	2021 Q2	2020 Q2
OPERATING ACTIVITIES
Net Income	$328.6M	$182.9M	$265.5M
YoY Change	42.19%	-31.11%	-5.58%
Depreciation, Depletion And Amortization	$30.40M	$136.0M	$140.7M
YoY Change	-79.69%	-3.34%	-7.19%
Cash From Operating Activities	$455.1M	$706.2M	$632.5M
YoY Change	6.73%	11.65%	48.51%
INVESTING ACTIVITIES
Capital Expenditures	-$24.80M	-$26.70M	-$38.40M
YoY Change	12.73%	-30.47%	4.35%
Acquisitions
YoY Change
Other Investing Activities	-$374.3M	-$1.069B	-$1.175B
YoY Change	-1756.19%	-9.05%	94.13%
Cash From Investing Activities	-$399.1M	-$1.095B	-$1.213B
YoY Change	-66616.67%	-9.73%	88.99%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-57.40M	-49.60M	409.2M
YoY Change	-88.26%	-112.12%	90.5%
NET CHANGE
Cash From Operating Activities	455.1M	706.2M	632.5M
Cash From Investing Activities	-399.1M	-1.095B	-1.213B
Cash From Financing Activities	-57.40M	-49.60M	409.2M
Net Change In Cash	-1.400M	-438.7M	-171.6M
YoY Change	-97.73%	155.65%	13100.0%
FREE CASH FLOW
Cash From Operating Activities	$455.1M	$706.2M	$632.5M
Capital Expenditures	-$24.80M	-$26.70M	-$38.40M
Free Cash Flow	$479.9M	$732.9M	$670.9M
YoY Change	7.02%	9.24%	45.0%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2021
	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	Q2
	dei	Amendment Flag AmendmentFlag	false
	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
	dei	Entity Central Index Key EntityCentralIndexKey	0000005513
	dei	Document Type DocumentType	10-Q
	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
	dei	Entity Small Business EntitySmallBusiness	false
	dei	Entity File Number EntityFileNumber	001-11294
	dei	Document Quarterly Report DocumentQuarterlyReport	true
	dei	Document Period End Date DocumentPeriodEndDate	2021-06-30
	dei	Document Transition Report DocumentTransitionReport	false
	dei	Entity Registrant Name EntityRegistrantName	Unum Group
	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	62-1598430
	dei	Entity Address Address Line1 EntityAddressAddressLine1	1 Fountain Square
	dei	Entity Address City Or Town EntityAddressCityOrTown	Chattanooga,
	dei	Entity Address State Or Province EntityAddressStateOrProvince	TN
	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	37402
	dei	City Area Code CityAreaCode	423
	dei	Local Phone Number LocalPhoneNumber	294-1011
	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
	dei	Entity Shell Company EntityShellCompany	false
CY2021Q3	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	204393640	shares
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	us-gaap	Net Investment Income NetInvestmentIncome	1112200000	USD
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	us-gaap	Gain Loss On Investments GainLossOnInvestments	85500000	USD
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	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	1600000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	800000	USD
CY2021Q2	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	9300000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-3000000.0	USD
CY2021Q2	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	36910700000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	36546500000	USD
CY2021Q2	us-gaap	Other Long Term Investments OtherLongTermInvestments	1062900000	USD
CY2021Q2	us-gaap	Accounts Receivable Net AccountsReceivableNet	31000000.0	USD
CY2021Q2	us-gaap	Liability For Future Policy Benefits And Unpaid Claims And Claims Adjustment Expense LiabilityForFuturePolicyBenefitsAndUnpaidClaimsAndClaimsAdjustmentExpense	48952000000.0	USD
CY2021Q2	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2020Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2020Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	306566572	shares
CY2020Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	11269600000	USD
CY2021Q2	us-gaap	Treasury Stock Shares TreasuryStockShares	102876514	shares
CY2020Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	102876514	shares
	us-gaap	Net Investment Income NetInvestmentIncome	1154000000.0	USD
CY2021Q2	us-gaap	Gain Loss On Investments GainLossOnInvestments	900000	USD
CY2021Q2	us-gaap	Policyholder Benefits And Claims Incurred Net PolicyholderBenefitsAndClaimsIncurredNet	1854100000	USD
CY2021Q2	us-gaap	Insurance Commissions InsuranceCommissions	259700000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-66600000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	1100000	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	2400000	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	3000000.0	USD
CY2021Q2	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-4100000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-3900000	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-7900000	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-10900000	USD
CY2021Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	247000000.0	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	544300000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-152100000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	289900000	USD
CY2021Q2	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	429900000	USD
CY2020Q2	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	809800000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	716400000	USD
CY2020Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.285
	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.570
	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.570
CY2021Q2	us-gaap	Stockholders Equity StockholdersEquity	10947500000	USD
CY2020Q2	us-gaap	Stockholders Equity StockholdersEquity	10561400000	USD
CY2021Q2	us-gaap	Stockholders Equity StockholdersEquity	10947500000	USD
CY2020Q2	us-gaap	Stockholders Equity StockholdersEquity	10561400000	USD
	us-gaap	Net Income Loss NetIncomeLoss	335900000	USD
	us-gaap	Net Income Loss NetIncomeLoss	426500000	USD
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	us-gaap	Deferred Policy Acquisition Costs Period Increase Decrease DeferredPolicyAcquisitionCostsPeriodIncreaseDecrease	-42100000	USD
	us-gaap	Deferred Policy Acquisition Costs Period Increase Decrease DeferredPolicyAcquisitionCostsPeriodIncreaseDecrease	-5000000.0	USD
	us-gaap	Increase Decrease In Other Accrued Liabilities IncreaseDecreaseInOtherAccruedLiabilities	-64800000	USD
	us-gaap	Increase Decrease In Insurance Liabilities IncreaseDecreaseInInsuranceLiabilities	243800000	USD
	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	185200000	USD
	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	82300000	USD
	us-gaap	Increase Decrease In Accrued Investment Income Receivable IncreaseDecreaseInAccruedInvestmentIncomeReceivable	246700000	USD
	us-gaap	Increase Decrease In Accrued Investment Income Receivable IncreaseDecreaseInAccruedInvestmentIncomeReceivable	163000000.0	USD
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	us-gaap	Gain Loss On Investments GainLossOnInvestments	-110200000	USD
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	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	55800000	USD
	unm	Net Cash Paid In Relation To Reinsurance Agreement NetCashPaidInRelationToReinsuranceAgreement	456800000	USD
	unm	Net Cash Paid In Relation To Reinsurance Agreement NetCashPaidInRelationToReinsuranceAgreement	0	USD
	us-gaap	Increase Decrease In Prepaid Reinsurance Premiums IncreaseDecreaseInPrepaidReinsurancePremiums	-39700000	USD
	us-gaap	Increase Decrease In Prepaid Reinsurance Premiums IncreaseDecreaseInPrepaidReinsurancePremiums	0	USD
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	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	891700000	USD
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	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	167900000	USD
	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	250200000	USD
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	us-gaap	Payments For Proceeds From Short Term Investments PaymentsForProceedsFromShortTermInvestments	1251000000.0	USD
	us-gaap	Increase Decrease In Cash Collateral For Loaned Securities IncreaseDecreaseInCashCollateralForLoanedSecurities	72800000	USD
	us-gaap	Increase Decrease In Cash Collateral For Loaned Securities IncreaseDecreaseInCashCollateralForLoanedSecurities	187000000.0	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	77500000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-506700000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1090700000	USD
	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	0	USD
	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	494100000	USD
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	us-gaap	Payments Of Debt Extinguishment Costs PaymentsOfDebtExtinguishmentCosts	62800000	USD
	us-gaap	Payments Of Debt Extinguishment Costs PaymentsOfDebtExtinguishmentCosts	0	USD
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	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	2300000	USD
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	unm	Cash Received Related To Active Life Volatility Cover Agreement Reinsurance Agreement CashReceivedRelatedToActiveLifeVolatilityCoverAgreementReinsuranceAgreement	0	USD
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CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	197000000.0	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	84100000	USD
CY2021Q2	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	123100000	USD
CY2020Q2	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	165600000	USD
CY2021Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	43513800000	USD
CY2021Q2	us-gaap	Derivative Assets DerivativeAssets	23400000	USD
CY2021Q2	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	33300000	USD
CY2021Q2	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	44428700000	USD
CY2021Q2	us-gaap	Derivative Liabilities DerivativeLiabilities	65600000	USD
CY2020Q4	unm	Policy Loans Cededto Reinsurers PolicyLoansCededtoReinsurers	3390600000	USD
CY2021Q2	unm	Policy Loans Cededto Reinsurers PolicyLoansCededtoReinsurers	3317400000	USD
CY2021Q2	unm	Available For Sale Securities Debt Maturities Within One Year Unrealized Gain Position Gross Gain AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearUnrealizedGainPositionGrossGain	15400000	USD
CY2021Q2	unm	Available For Sale Securities Debt Maturities Within One Year Unrealized Loss Position Gross Loss AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearUnrealizedLossPositionGrossLoss	1200000	USD
CY2021Q2	unm	Debt Securities Available For Sale Amortized Cost Maturity Allocated And Single Maturity Date After Year One Through Five Net DebtSecuritiesAvailableForSaleAmortizedCostMaturityAllocatedAndSingleMaturityDateAfterYearOneThroughFiveNet	6585700000	USD
CY2021Q2	unm	Available For Sale Securities Debt Maturities After One Through Five Years Unrealized Gain Position Gross Gain AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsUnrealizedGainPositionGrossGain	636400000	USD
CY2021Q2	unm	Available For Sale Securities Debt Maturities After One Through Five Years Unrealized Loss Position Gross Loss AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsUnrealizedLossPositionGrossLoss	8800000	USD
CY2021Q2	unm	Debt Securities Available For Sale Amortized Cost Maturity Allocated And Single Maturity Date After Year5 Through10 Net DebtSecuritiesAvailableForSaleAmortizedCostMaturityAllocatedAndSingleMaturityDateAfterYear5Through10Net	10532300000	USD
CY2021Q2	unm	Available For Sale Securities Debt Maturities After Five Through Ten Years Unrealized Gain Position Gross Gain AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsUnrealizedGainPositionGrossGain	1681400000	USD
CY2021Q2	unm	Available For Sale Securities Debt Maturities After Five Through Ten Years Unrealized Loss Position Gross Loss AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsUnrealizedLossPositionGrossLoss	8200000	USD
CY2021Q2	unm	Available For Sale Securities Debt Maturities After Ten Years Unrealized Gain Position Gross Gain AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsUnrealizedGainPositionGrossGain	4264300000	USD
CY2021Q2	unm	Available For Sale Securities Debt Maturities Amortized Cost Gross Subtotal Net AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostGrossSubtotalNet	36195100000	USD
CY2021Q2	unm	Available For Sale Securities Debt Maturities Unrealized Gain Position Gross Gain Gross Subtotal AvailableForSaleSecuritiesDebtMaturitiesUnrealizedGainPositionGrossGainGrossSubtotal	6597500000	USD
CY2021Q2	unm	Available For Sale Securities Debt Maturities Unrealized Gain Position Gross Loss Gross Subtotal AvailableForSaleSecuritiesDebtMaturitiesUnrealizedGainPositionGrossLossGrossSubtotal	60000000.0	USD
CY2021Q2	unm	Debt Securities Available For Sale Maturity Without Single Maturity Date Amortized Cost Net DebtSecuritiesAvailableForSaleMaturityWithoutSingleMaturityDateAmortizedCostNet	715600000	USD
CY2021Q2	unm	Available For Sale Securities Debt Maturities Without Single Maturity Date Unrealized Gain Position Gross Gain AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateUnrealizedGainPositionGrossGain	65700000	USD
CY2021Q2	unm	Available For Sale Securities Debt Maturities Without Single Maturity Date Unrealized Loss Position Gross Loss AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateUnrealizedLossPositionGrossLoss	100000	USD
CY2021Q2	unm	Debt Securities Available For Sale Amortized Cost Net Of Allowance For Credit Losses DebtSecuritiesAvailableForSaleAmortizedCostNetOfAllowanceForCreditLosses	36910700000	USD
CY2021Q2	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	6663200000	USD
CY2020Q2	us-gaap	Interest And Debt Expense InterestAndDebtExpense	47500000	USD
CY2021Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	43513800000	USD
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CY2020Q4	unm	Available For Sale Securities Debt Maturities After Ten Years Unrealized Gain Position Gross Gain AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsUnrealizedGainPositionGrossGain	5041300000	USD
CY2020Q4	unm	Available For Sale Securities Debt Maturities After Ten Years Unrealized Loss Position Gross Loss AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsUnrealizedLossPositionGrossLoss	19200000	USD
CY2020Q4	unm	Available For Sale Securities Debt Maturities Amortized Cost Gross Subtotal Net AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostGrossSubtotalNet	35519800000	USD
CY2020Q4	unm	Available For Sale Securities Debt Maturities Unrealized Gain Position Gross Gain Gross Subtotal AvailableForSaleSecuritiesDebtMaturitiesUnrealizedGainPositionGrossGainGrossSubtotal	7565500000	USD
CY2020Q4	unm	Available For Sale Securities Debt Maturities Unrealized Gain Position Gross Loss Gross Subtotal AvailableForSaleSecuritiesDebtMaturitiesUnrealizedGainPositionGrossLossGrossSubtotal	55700000	USD
CY2020Q4	unm	Debt Securities Available For Sale Maturity Without Single Maturity Date Amortized Cost Net DebtSecuritiesAvailableForSaleMaturityWithoutSingleMaturityDateAmortizedCostNet	1019900000	USD
CY2020Q4	unm	Available For Sale Securities Debt Maturities Without Single Maturity Date Unrealized Gain Position Gross Gain AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateUnrealizedGainPositionGrossGain	88000000.0	USD
CY2020Q4	unm	Available For Sale Securities Debt Maturities Without Single Maturity Date Unrealized Loss Position Gross Loss AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateUnrealizedLossPositionGrossLoss	200000	USD
CY2020Q4	unm	Debt Securities Available For Sale Amortized Cost Net Of Allowance For Credit Losses DebtSecuritiesAvailableForSaleAmortizedCostNetOfAllowanceForCreditLosses	36539700000	USD
CY2020Q4	unm	Availableforsale Securities Debt Maturities Unrealized Gain Position Gross Gain AvailableforsaleSecuritiesDebtMaturitiesUnrealizedGainPositionGrossGain	7653500000	USD
CY2020Q4	unm	Available For Sale Securities Unrealized Loss Position Gross Loss Subtotal AvailableForSaleSecuritiesUnrealizedLossPositionGrossLossSubtotal	55900000	USD
CY2021Q2	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	60100000	USD
CY2021Q2	unm	Fixed Maturity Securities In Unrealized Loss Position Percent Of Total FixedMaturitySecuritiesInUnrealizedLossPositionPercentOfTotal	1.000
CY2021Q2	unm	Commitment To Fund Private Placement Fixed Maturity Securities CommitmentToFundPrivatePlacementFixedMaturitySecurities	148600000	USD
CY2021Q2	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	5400000	USD
CY2020Q2	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	8300000	USD
	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	10800000	USD
	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	16600000	USD
CY2021Q2	us-gaap	Deferred Policy Acquisition Cost Amortization Expense DeferredPolicyAcquisitionCostAmortizationExpense	136000000.0	USD
CY2021Q2	us-gaap	Labor And Related Expense LaborAndRelatedExpense	247400000	USD
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	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	491900000	USD
CY2021Q2	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	2730400000	USD
CY2020Q2	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	2683600000	USD
	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	5603600000	USD
	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	5352600000	USD
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CY2021Q2	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	50400000	USD
CY2020Q2	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	70600000	USD
	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	117900000	USD
	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	128200000	USD
CY2020Q2	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	5500000	USD
	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	7400000	USD
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CY2021Q2	unm	Tax Benefitsfrom Low Income Housing Investments TaxBenefitsfromLowIncomeHousingInvestments	1700000	USD
CY2020Q2	unm	Tax Benefitsfrom Low Income Housing Investments TaxBenefitsfromLowIncomeHousingInvestments	2800000	USD
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CY2021Q2	us-gaap	Mortgage Loans On Real Estate Commercial And Consumer Net MortgageLoansOnRealEstateCommercialAndConsumerNet	2387100000	USD
CY2021Q2	us-gaap	Mortgage Loans On Real Estate Commercial And Consumer Net MortgageLoansOnRealEstateCommercialAndConsumerNet	2387100000	USD
CY2020Q4	us-gaap	Mortgage Loans On Real Estate Commercial And Consumer Net MortgageLoansOnRealEstateCommercialAndConsumerNet	2432100000	USD
CY2021Q2	us-gaap	Mortgage Loans On Real Estate Commercial And Consumer Net MortgageLoansOnRealEstateCommercialAndConsumerNet	2387100000	USD
CY2021Q2	us-gaap	Mortgage Loans On Real Estate Commercial And Consumer Net MortgageLoansOnRealEstateCommercialAndConsumerNet	2387100000	USD
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CY2021Q2	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	0	USD
CY2020Q2	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	0	USD
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CY2021Q2	unm	Commitments To Fund Commercial Mortgage Loans CommitmentsToFundCommercialMortgageLoans	58500000	USD
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CY2021Q2	unm	Collateral Requirements Minimum Percentage Collateral To Fair Value Of Securities Loaned Or Purchased Under Repurchase Agreements CollateralRequirementsMinimumPercentageCollateralToFairValueOfSecuritiesLoanedOrPurchasedUnderRepurchaseAgreements	1.02
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CY2021Q2	us-gaap	Securities Borrowed Gross SecuritiesBorrowedGross	231700000	USD
CY2020Q4	us-gaap	Securities Borrowed Gross SecuritiesBorrowedGross	96600000	USD
CY2021Q2	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	0	USD
CY2021Q2	us-gaap	Federal Home Loan Bank Stock FederalHomeLoanBankStock	26100000	USD
CY2020Q4	us-gaap	Federal Home Loan Bank Stock FederalHomeLoanBankStock	28200000	USD
CY2021Q2	us-gaap	Federal Home Loan Bank Advances Branch Of Fhlb Bank Amount Of Advances By Branch FederalHomeLoanBankAdvancesBranchOfFHLBBankAmountOfAdvancesByBranch	286600000	USD
CY2020Q4	us-gaap	Federal Home Loan Bank Advances Branch Of Fhlb Bank Amount Of Advances By Branch FederalHomeLoanBankAdvancesBranchOfFHLBBankAmountOfAdvancesByBranch	312200000	USD
CY2021Q2	us-gaap	Federal Home Loan Bank Advances General Debt Obligations Disclosures Collateral Pledged1 FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1	1791000000.0	USD
CY2020Q4	us-gaap	Federal Home Loan Bank Advances General Debt Obligations Disclosures Collateral Pledged1 FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1	2016500000	USD
CY2021Q2	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	23400000	USD
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CY2021Q2	us-gaap	Derivative Collateral Obligation To Return Cash DerivativeCollateralObligationToReturnCash	14400000	USD
CY2021Q2	us-gaap	Derivative Fair Value Of Derivative Asset Amount Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral	1300000	USD
CY2021Q2	us-gaap	Securities Borrowed Gross SecuritiesBorrowedGross	231700000	USD
CY2021Q2	us-gaap	Securities Borrowed Liability SecuritiesBorrowedLiability	0	USD
CY2021Q2	us-gaap	Securities Borrowed SecuritiesBorrowed	231700000	USD
CY2021Q2	us-gaap	Securities Borrowed Collateral Obligation To Return Securities SecuritiesBorrowedCollateralObligationToReturnSecurities	123200000	USD
CY2021Q2	us-gaap	Net Income Loss NetIncomeLoss	182900000	USD
	us-gaap	Net Income Loss NetIncomeLoss	426500000	USD
CY2021Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.89
CY2020Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.30
CY2021Q2	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax	226900000	USD
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	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	16600000	USD
CY2021Q2	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	1200000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	183800000	USD
CY2021Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.285
	us-gaap	Increase Decrease In Insurance Liabilities IncreaseDecreaseInInsuranceLiabilities	378200000	USD
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	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-52300000	USD
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CY2021Q2	us-gaap	Derivative Liability Securities Sold Under Agreements To Resell Securities Loaned DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoaned	152900000	USD
CY2021Q2	us-gaap	Derivative Liability Securities Sold Under Agreements To Resell Securities Loaned Collateral Right To Reclaim Securities DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedCollateralRightToReclaimSecurities	152900000	USD
CY2021Q2	us-gaap	Derivative Liability Securities Sold Under Agreements To Resell Securities Loaned Collateral Right To Reclaim Cash DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedCollateralRightToReclaimCash	0	USD
CY2021Q2	us-gaap	Derivative Liability Securities Sold Under Agreements To Resell Securities Loaned Amount Offset Against Collateral DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedAmountOffsetAgainstCollateral	0	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	19800000	USD
CY2020Q4	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	0	USD
CY2020Q4	us-gaap	Derivative Assets DerivativeAssets	19800000	USD
CY2020Q4	us-gaap	Derivative Collateral Obligation To Return Securities DerivativeCollateralObligationToReturnSecurities	10100000	USD
CY2020Q4	us-gaap	Derivative Collateral Obligation To Return Cash DerivativeCollateralObligationToReturnCash	8700000	USD
CY2020Q4	us-gaap	Securities Borrowed Liability SecuritiesBorrowedLiability	0	USD
CY2020Q4	us-gaap	Securities Borrowed Gross SecuritiesBorrowedGross	96600000	USD
CY2020Q4	us-gaap	Securities Borrowed SecuritiesBorrowed	96600000	USD
CY2020Q4	us-gaap	Securities Borrowed Collateral Obligation To Return Securities SecuritiesBorrowedCollateralObligationToReturnSecurities	79000000.0	USD
CY2020Q4	us-gaap	Securities Borrowed Amount Offset Against Collateral SecuritiesBorrowedAmountOffsetAgainstCollateral	0	USD
CY2020Q4	us-gaap	Derivative Asset Securities Purchased Under Agreements To Resell Securities Borrowed Gross DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowedGross	116400000	USD
CY2020Q4	us-gaap	Derivative Asset Securities Purchased Under Agreements To Resell Securities Borrowed Liability DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowedLiability	0	USD
CY2020Q4	us-gaap	Derivative Asset Securities Purchased Under Agreements To Resell Securities Borrowed DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowed	116400000	USD
CY2020Q4	us-gaap	Derivative Asset Securities Purchased Under Agreements To Resell Securities Borrowed Collateral Obligation To Return Securities DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowedCollateralObligationToReturnSecurities	89100000	USD
CY2020Q4	us-gaap	Derivative Asset Securities Purchased Under Agreements To Resell Securities Borrowed Amount Offset Against Collateral DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowedAmountOffsetAgainstCollateral	1000000.0	USD
CY2020Q4	us-gaap	Securities Loaned Gross SecuritiesLoanedGross	17600000	USD
CY2020Q4	us-gaap	Securities Loaned Asset SecuritiesLoanedAsset	0	USD
CY2020Q4	us-gaap	Securities Loaned SecuritiesLoaned	17600000	USD
CY2020Q4	us-gaap	Securities Loaned Collateral Right To Reclaim Cash SecuritiesLoanedCollateralRightToReclaimCash	0	USD
CY2020Q4	us-gaap	Securities Loaned Amount Offset Against Collateral SecuritiesLoanedAmountOffsetAgainstCollateral	0	USD
CY2020Q4	us-gaap	Derivative Liability Securities Sold Under Agreements To Resell Securities Loaned Gross DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedGross	77300000	USD
CY2020Q4	us-gaap	Derivative Liability Securities Sold Under Agreements To Resell Securities Loaned Asset DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedAsset	0	USD
CY2020Q4	us-gaap	Derivative Liability Securities Sold Under Agreements To Resell Securities Loaned DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoaned	77300000	USD
CY2020Q4	us-gaap	Derivative Liability Securities Sold Under Agreements To Resell Securities Loaned Collateral Right To Reclaim Securities DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedCollateralRightToReclaimSecurities	76600000	USD
CY2020Q4	us-gaap	Derivative Liability Securities Sold Under Agreements To Resell Securities Loaned Collateral Right To Reclaim Cash DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedCollateralRightToReclaimCash	0	USD
CY2020Q4	us-gaap	Derivative Liability Securities Sold Under Agreements To Resell Securities Loaned Amount Offset Against Collateral DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedAmountOffsetAgainstCollateral	700000	USD
CY2021Q2	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	574300000	USD
CY2020Q2	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	579600000	USD
	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	1133600000	USD
	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	1176300000	USD
CY2021Q2	us-gaap	Investment Income Investment Expense InvestmentIncomeInvestmentExpense	7800000	USD
CY2020Q2	us-gaap	Investment Income Investment Expense InvestmentIncomeInvestmentExpense	7600000	USD
	us-gaap	Investment Income Investment Expense InvestmentIncomeInvestmentExpense	16100000	USD
CY2021Q2	unm	Investment Income On Pfa Assets InvestmentIncomeOnPfaAssets	3000000.0	USD
CY2020Q2	unm	Investment Income On Pfa Assets InvestmentIncomeOnPfaAssets	3000000.0	USD
	unm	Investment Income On Pfa Assets InvestmentIncomeOnPfaAssets	6100000	USD
	unm	Investment Income On Pfa Assets InvestmentIncomeOnPfaAssets	6200000	USD
CY2021Q2	us-gaap	Net Investment Income NetInvestmentIncome	563500000	USD
CY2020Q2	us-gaap	Net Investment Income NetInvestmentIncome	569000000.0	USD
	us-gaap	Net Investment Income NetInvestmentIncome	1112200000	USD
	us-gaap	Net Investment Income NetInvestmentIncome	1154000000.0	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	2300000	USD
CY2020Q2	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	3600000	USD
	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	73600000	USD
	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	5000000.0	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	2500000	USD
CY2020Q2	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	4100000	USD
	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	4800000	USD
CY2021Q2	unm	Other Investments Gross Realized Gains OtherInvestmentsGrossRealizedGains	1000000.0	USD
CY2020Q2	unm	Other Investments Gross Realized Gains OtherInvestmentsGrossRealizedGains	0	USD
	unm	Other Investments Gross Realized Gains OtherInvestmentsGrossRealizedGains	3500000	USD
	unm	Other Investments Gross Realized Gains OtherInvestmentsGrossRealizedGains	300000	USD
CY2021Q2	unm	Other Investments Gross Realized Losses OtherInvestmentsGrossRealizedLosses	0	USD
CY2020Q2	unm	Other Investments Gross Realized Losses OtherInvestmentsGrossRealizedLosses	0	USD
	unm	Other Investments Gross Realized Losses OtherInvestmentsGrossRealizedLosses	0	USD
	unm	Other Investments Gross Realized Losses OtherInvestmentsGrossRealizedLosses	200000	USD
CY2020Q2	unm	Financing Receivables Allowance For Credit Losses Period Increase Decrease Commercial Mortgage Loans And Unfunded Loan Commitments FinancingReceivablesAllowanceForCreditLossesPeriodIncreaseDecreaseCommercialMortgageLoansAndUnfundedLoanCommitments	2000000.0	USD
	unm	Financing Receivables Allowance For Credit Losses Period Increase Decrease Commercial Mortgage Loans And Unfunded Loan Commitments FinancingReceivablesAllowanceForCreditLossesPeriodIncreaseDecreaseCommercialMortgageLoansAndUnfundedLoanCommitments	-1600000	USD
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CY2021Q2	us-gaap	Embedded Derivative Gain Loss On Embedded Derivative Net EmbeddedDerivativeGainLossOnEmbeddedDerivativeNet	1700000	USD
CY2020Q2	us-gaap	Embedded Derivative Gain Loss On Embedded Derivative Net EmbeddedDerivativeGainLossOnEmbeddedDerivativeNet	41900000	USD
	us-gaap	Embedded Derivative Gain Loss On Embedded Derivative Net EmbeddedDerivativeGainLossOnEmbeddedDerivativeNet	18600000	USD
	us-gaap	Embedded Derivative Gain Loss On Embedded Derivative Net EmbeddedDerivativeGainLossOnEmbeddedDerivativeNet	-45000000.0	USD
CY2020Q2	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	-1000000.0	USD
	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	1600000	USD
	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	-1700000	USD
CY2021Q2	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	-400000	USD
CY2020Q2	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	800000	USD
	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	-500000	USD
	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	100000	USD
CY2020Q2	us-gaap	Gain Loss On Investments GainLossOnInvestments	33800000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	85500000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	-110200000	USD
CY2021Q2	us-gaap	Derivative Net Liability Position Aggregate Fair Value DerivativeNetLiabilityPositionAggregateFairValue	44400000	USD
CY2020Q4	us-gaap	Derivative Net Liability Position Aggregate Fair Value DerivativeNetLiabilityPositionAggregateFairValue	59700000	USD
CY2020Q1	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	931400000	USD
CY2020Q2	unm	Notional Amount Of Derivatives Additions NotionalAmountOfDerivativesAdditions	0	USD
CY2020Q2	unm	Notional Amount Of Derivatives Terminations NotionalAmountOfDerivativesTerminations	0	USD
CY2020Q2	unm	Notional Amount Of Derivatives Foreign Currency NotionalAmountOfDerivativesForeignCurrency	0	USD
CY2020Q2	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	931400000	USD
CY2019Q4	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	881400000	USD
	unm	Notional Amount Of Derivatives Terminations NotionalAmountOfDerivativesTerminations	1300000	USD
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CY2020Q2	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	931400000	USD
CY2021Q1	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	846300000	USD
CY2021Q2	unm	Notional Amount Of Derivatives Additions NotionalAmountOfDerivativesAdditions	361500000	USD
CY2021Q2	unm	Notional Amount Of Derivatives Terminations NotionalAmountOfDerivativesTerminations	288700000	USD
CY2021Q2	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	919100000	USD
CY2020Q4	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	744400000	USD
	unm	Notional Amount Of Derivatives Additions NotionalAmountOfDerivativesAdditions	463200000	USD
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CY2021Q2	us-gaap	Net Investment Income NetInvestmentIncome	563500000	USD
CY2021Q2	us-gaap	Gain Loss On Investments GainLossOnInvestments	900000	USD
CY2021Q2	us-gaap	Interest And Debt Expense InterestAndDebtExpense	45300000	USD
CY2020Q2	us-gaap	Net Investment Income NetInvestmentIncome	569000000.0	USD
CY2020Q2	us-gaap	Gain Loss On Investments GainLossOnInvestments	33800000	USD
CY2020Q2	us-gaap	Interest And Debt Expense InterestAndDebtExpense	47500000	USD
	us-gaap	Net Investment Income NetInvestmentIncome	1112200000	USD
	us-gaap	Interest And Debt Expense InterestAndDebtExpense	89700000	USD
	us-gaap	Net Investment Income NetInvestmentIncome	1154000000.0	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	-110200000	USD
	us-gaap	Interest And Debt Expense InterestAndDebtExpense	93200000	USD
CY2021Q1	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	-24900000	USD
CY2021Q2	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	253900000	USD
CY2021Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	247000000.0	USD
CY2021Q2	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	222100000	USD
	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-193300000	USD
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	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-152100000	USD
CY2021Q2	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	222100000	USD
CY2019Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	37300000	USD
	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	265500000	USD
	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-24400000	USD
CY2019Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	23076700000	USD
CY2019Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	23076700000	USD
CY2020Q4	us-gaap	Reinsurance Receivables Incurred But Not Reported Claims ReinsuranceReceivablesIncurredButNotReportedClaims	8378900000	USD
CY2019Q4	us-gaap	Reinsurance Receivables Incurred But Not Reported Claims ReinsuranceReceivablesIncurredButNotReportedClaims	2246800000	USD
CY2019Q4	us-gaap	Reinsurance Receivables Incurred But Not Reported Claims ReinsuranceReceivablesIncurredButNotReportedClaims	2246800000	USD
CY2020Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	15801300000	USD
CY2019Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	20829900000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	3461000000.0	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	3187200000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities ProceedsFromSaleOfAvailableForSaleSecurities	363500000	USD
	us-gaap	Payments To Acquire Available For Sale Securities PaymentsToAcquireAvailableForSaleSecurities	2122200000	USD
	us-gaap	Payments To Acquire Available For Sale Securities PaymentsToAcquireAvailableForSaleSecurities	1068300000	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	57600000	USD
	us-gaap	Payments Of Dividends PaymentsOfDividends	115800000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-111400000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	319800000	USD
	us-gaap	Basis Of Accounting BasisOfAccounting	<div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The accompanying consolidated financial statements of Unum Group and its subsidiaries (the Company) have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. For further information, refer to the consolidated financial statements and footnotes included in our annual report on Form 10-K for the year ended December 31, 2020.</span></div><div><span><br/></span></div><div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">In our opinion, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Interim results are not necessarily indicative of full year performance, particularly when considering the risks and uncertainties associated with the coronavirus disease 2019 (COVID-19) and the impacts it may have on our financial position, results of operations, liquidity and capital resources, and overall business operations.</span></div>
CY2021Q2	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	65600000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	44137300000	USD
CY2020Q4	us-gaap	Derivative Assets DerivativeAssets	19800000	USD
CY2020Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	28300000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	2546600000	USD
	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	3367100000	USD
	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	3562500000	USD
	unm	Reserves Ceded Pursuant To Reinsurance Transaction ReservesCededPursuantToReinsuranceTransaction	990000000.0	USD
	unm	Reserves Ceded Pursuant To Reinsurance Transaction ReservesCededPursuantToReinsuranceTransaction	0	USD
CY2021Q2	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	15072100000	USD
CY2020Q2	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	20582400000	USD
CY2021Q2	us-gaap	Reinsurance Receivables Incurred But Not Reported Claims ReinsuranceReceivablesIncurredButNotReportedClaims	9042200000	USD
CY2020Q2	us-gaap	Reinsurance Receivables Incurred But Not Reported Claims ReinsuranceReceivablesIncurredButNotReportedClaims	2260200000	USD
CY2021Q2	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	24114300000	USD
CY2020Q2	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	22842600000	USD
CY2021Q2	unm	Policy And Contract Benefits PolicyAndContractBenefits	1890400000	USD
CY2020Q2	unm	Policy And Contract Benefits PolicyAndContractBenefits	1778800000	USD
CY2021Q2	us-gaap	Liability For Future Policy Benefits And Unpaid Claims And Claims Adjustment Expense LiabilityForFuturePolicyBenefitsAndUnpaidClaimsAndClaimsAdjustmentExpense	48952000000.0	USD
CY2020Q2	us-gaap	Liability For Future Policy Benefits And Unpaid Claims And Claims Adjustment Expense LiabilityForFuturePolicyBenefitsAndUnpaidClaimsAndClaimsAdjustmentExpense	48335100000	USD
CY2021Q2	us-gaap	Liability For Future Policy Benefits LiabilityForFuturePolicyBenefits	50842400000	USD
CY2020Q2	us-gaap	Liability For Future Policy Benefits LiabilityForFuturePolicyBenefits	50113900000	USD
CY2021Q2	unm	Life Reserves For Future Policy And Contract Benefits LifeReservesForFuturePolicyAndContractBenefits	8431100000	USD
CY2020Q2	unm	Life Reserves For Future Policy And Contract Benefits LifeReservesForFuturePolicyAndContractBenefits	8436700000	USD
CY2021Q2	unm	Accident And Health Active Life Reserves AccidentAndHealthActiveLifeReserves	12910400000	USD
CY2020Q2	unm	Accident And Health Active Life Reserves AccidentAndHealthActiveLifeReserves	12374800000	USD
CY2021Q2	unm	Unrealized Adjustment To Reserves For Future Policy And Contract Benefits UnrealizedAdjustmentToReservesForFuturePolicyAndContractBenefits	5386600000	USD
CY2020Q2	unm	Unrealized Adjustment To Reserves For Future Policy And Contract Benefits UnrealizedAdjustmentToReservesForFuturePolicyAndContractBenefits	6459800000	USD
CY2020Q2	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	22842600000	USD
	us-gaap	Number Of Operating Segments NumberOfOperatingSegments	3	Integer
CY2021Q2	us-gaap	Assets Assets	70807900000	USD
CY2020Q4	us-gaap	Assets Assets	70625800000	USD
CY2020Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	44932900000	USD
CY2020Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	99500000	USD
CY2020Q4	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	99500000	USD
CY2021Q2	unm	Debt Securities Available For Sale Amortized Cost Maturity Allocated And Single Maturity Date Year One Net DebtSecuritiesAvailableForSaleAmortizedCostMaturityAllocatedAndSingleMaturityDateYearOneNet	838300000	USD
CY2021Q2	unm	Debt Securities Available For Sale Amortized Cost Maturity Allocated And Single Maturity Date After Year10 Net DebtSecuritiesAvailableForSaleAmortizedCostMaturityAllocatedAndSingleMaturityDateAfterYear10Net	18238800000	USD
CY2021Q2	unm	Available For Sale Securities Debt Maturities After Ten Years Unrealized Loss Position Gross Loss AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsUnrealizedLossPositionGrossLoss	41800000	USD
CY2021Q2	unm	Availableforsale Securities Debt Maturities Unrealized Gain Position Gross Gain AvailableforsaleSecuritiesDebtMaturitiesUnrealizedGainPositionGrossGain	6663200000	USD
CY2021Q2	unm	Available For Sale Securities Unrealized Loss Position Gross Loss Subtotal AvailableForSaleSecuritiesUnrealizedLossPositionGrossLossSubtotal	60100000	USD
CY2020Q4	unm	Debt Securities Available For Sale Amortized Cost Maturity Allocated And Single Maturity Date Year One Net DebtSecuritiesAvailableForSaleAmortizedCostMaturityAllocatedAndSingleMaturityDateYearOneNet	881800000	USD
CY2020Q4	unm	Available For Sale Securities Debt Maturities Within One Year Unrealized Gain Position Gross Gain AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearUnrealizedGainPositionGrossGain	19500000	USD
CY2020Q4	unm	Available For Sale Securities Debt Maturities Within One Year Unrealized Loss Position Gross Loss AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearUnrealizedLossPositionGrossLoss	2900000	USD
CY2020Q4	unm	Debt Securities Available For Sale Amortized Cost Maturity Allocated And Single Maturity Date After Year One Through Five Net DebtSecuritiesAvailableForSaleAmortizedCostMaturityAllocatedAndSingleMaturityDateAfterYearOneThroughFiveNet	6162600000	USD
CY2020Q4	unm	Available For Sale Securities Debt Maturities After One Through Five Years Unrealized Gain Position Gross Gain AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsUnrealizedGainPositionGrossGain	589900000	USD
CY2020Q4	unm	Available For Sale Securities Debt Maturities After One Through Five Years Unrealized Loss Position Gross Loss AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsUnrealizedLossPositionGrossLoss	22900000	USD
CY2021Q2	us-gaap	Net Income Loss NetIncomeLoss	182900000	USD
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	265500000	USD
	us-gaap	Net Income Loss NetIncomeLoss	335900000	USD
	us-gaap	Net Income Loss NetIncomeLoss	426500000	USD
CY2021Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	204504500	shares
CY2020Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	203624300	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	204323100	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	203466900	shares
CY2020Q2	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	46800	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	686700	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	48300	shares
CY2021Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	205273800	shares
CY2020Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	203671100	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	205009800	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	203515200	shares
CY2021Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.89
CY2020Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.30
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.64
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.10
CY2021Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.89
CY2020Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.30
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.64
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.10
CY2021Q2	unm	Outstanding Restricted Stock And Stock Success Unit Grant Prices Lower Limit OutstandingRestrictedStockAndStockSuccessUnitGrantPricesLowerLimit	12.45
CY2020Q4	unm	Debt Securities Available For Sale Amortized Cost Maturity Allocated And Single Maturity Date After Year5 Through10 Net DebtSecuritiesAvailableForSaleAmortizedCostMaturityAllocatedAndSingleMaturityDateAfterYear5Through10Net	10886900000	USD
CY2020Q4	unm	Available For Sale Securities Debt Maturities After Five Through Ten Years Unrealized Gain Position Gross Gain AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsUnrealizedGainPositionGrossGain	1914800000	USD
CY2020Q4	unm	Available For Sale Securities Debt Maturities After Five Through Ten Years Unrealized Loss Position Gross Loss AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsUnrealizedLossPositionGrossLoss	10700000	USD
CY2021Q2	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	3700000	USD
	unm	Tax Benefitsfrom Low Income Housing Investments TaxBenefitsfromLowIncomeHousingInvestments	5600000	USD
CY2021Q2	us-gaap	Qualified Affordable Housing Project Investments Commitment QualifiedAffordableHousingProjectInvestmentsCommitment	700000	USD
CY2021Q2	us-gaap	Mortgage Loans On Real Estate Commercial And Consumer Net MortgageLoansOnRealEstateCommercialAndConsumerNet	2387100000	USD
CY2020Q4	us-gaap	Mortgage Loans On Real Estate Commercial And Consumer Net MortgageLoansOnRealEstateCommercialAndConsumerNet	2432100000	USD
CY2021Q2	us-gaap	Mortgage Loans On Real Estate Commercial And Consumer Net MortgageLoansOnRealEstateCommercialAndConsumerNet	2387100000	USD
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	1500000	shares
CY2021Q2	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	25000000.0	shares
CY2021Q2	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.10
CY2021Q2	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
CY2021Q2	us-gaap	Premiums Receivable Allowance For Doubtful Accounts PremiumsReceivableAllowanceForDoubtfulAccounts	31000000.0	USD
CY2020Q4	us-gaap	Premiums Receivable Allowance For Doubtful Accounts PremiumsReceivableAllowanceForDoubtfulAccounts	38800000	USD
CY2021Q2	us-gaap	Premiums Receivable Gross PremiumsReceivableGross	576300000	USD
CY2020Q4	us-gaap	Premiums Receivable Gross PremiumsReceivableGross	525800000	USD
CY2021Q2	us-gaap	Premium Receivable Credit Loss Expense Reversal PremiumReceivableCreditLossExpenseReversal	2700000	USD
	us-gaap	Premium Receivable Credit Loss Expense Reversal PremiumReceivableCreditLossExpenseReversal	7800000	USD
CY2020Q2	us-gaap	Premiums Receivable Allowance For Doubtful Accounts PremiumsReceivableAllowanceForDoubtfulAccounts	47500000	USD
CY2020Q1	us-gaap	Premiums Receivable Allowance For Doubtful Accounts PremiumsReceivableAllowanceForDoubtfulAccounts	23800000	USD
CY2020Q2	us-gaap	Premiums Receivable Gross PremiumsReceivableGross	627000000.0	USD
CY2020Q4	us-gaap	Mortgage Loans On Real Estate Commercial And Consumer Net MortgageLoansOnRealEstateCommercialAndConsumerNet	2432100000	USD
CY2020Q4	us-gaap	Mortgage Loans On Real Estate Commercial And Consumer Net MortgageLoansOnRealEstateCommercialAndConsumerNet	2432100000	USD
CY2020Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	0	USD
CY2021Q2	us-gaap	Derivative Assets DerivativeAssets	23400000	USD
CY2021Q2	us-gaap	Derivative Collateral Obligation To Return Securities DerivativeCollateralObligationToReturnSecurities	7700000	USD
CY2021Q2	us-gaap	Securities Borrowed Collateral Obligation To Return Cash SecuritiesBorrowedCollateralObligationToReturnCash	108500000	USD
CY2021Q2	us-gaap	Securities Borrowed Amount Offset Against Collateral SecuritiesBorrowedAmountOffsetAgainstCollateral	0	USD
CY2021Q2	us-gaap	Derivative Asset Securities Purchased Under Agreements To Resell Securities Borrowed Gross DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowedGross	255100000	USD
CY2021Q2	us-gaap	Derivative Asset Securities Purchased Under Agreements To Resell Securities Borrowed Liability DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowedLiability	0	USD
CY2021Q2	us-gaap	Derivative Asset Securities Purchased Under Agreements To Resell Securities Borrowed DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowed	255100000	USD
CY2021Q2	us-gaap	Derivative Asset Securities Purchased Under Agreements To Resell Securities Borrowed Collateral Obligation To Return Securities DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowedCollateralObligationToReturnSecurities	130900000	USD
CY2021Q2	us-gaap	Derivative Asset Securities Purchased Under Agreements To Resell Securities Borrowed Collateral Obligation To Return Cash DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowedCollateralObligationToReturnCash	122900000	USD
CY2021Q2	us-gaap	Derivative Asset Securities Purchased Under Agreements To Resell Securities Borrowed Amount Offset Against Collateral DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowedAmountOffsetAgainstCollateral	1300000	USD
CY2021Q2	us-gaap	Securities Loaned Gross SecuritiesLoanedGross	108500000	USD
CY2021Q2	us-gaap	Securities Loaned Asset SecuritiesLoanedAsset	0	USD
CY2021Q2	us-gaap	Securities Loaned SecuritiesLoaned	108500000	USD
CY2021Q2	us-gaap	Securities Loaned Collateral Right To Reclaim Securities SecuritiesLoanedCollateralRightToReclaimSecurities	108500000	USD
CY2021Q2	us-gaap	Securities Loaned Collateral Right To Reclaim Cash SecuritiesLoanedCollateralRightToReclaimCash	0	USD
CY2021Q2	us-gaap	Securities Loaned Amount Offset Against Collateral SecuritiesLoanedAmountOffsetAgainstCollateral	0	USD
CY2021Q2	us-gaap	Derivative Liability Securities Sold Under Agreements To Resell Securities Loaned Gross DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedGross	152900000	USD
CY2021Q2	us-gaap	Derivative Liability Securities Sold Under Agreements To Resell Securities Loaned Asset DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedAsset	0	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Asset Amount Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral	1000000.0	USD
CY2020Q4	us-gaap	Securities Borrowed Collateral Obligation To Return Cash SecuritiesBorrowedCollateralObligationToReturnCash	17600000	USD
CY2020Q4	us-gaap	Derivative Asset Securities Purchased Under Agreements To Resell Securities Borrowed Collateral Obligation To Return Cash DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowedCollateralObligationToReturnCash	26300000	USD
CY2020Q4	us-gaap	Securities Loaned Collateral Right To Reclaim Securities SecuritiesLoanedCollateralRightToReclaimSecurities	17600000	USD
	us-gaap	Investment Income Investment Expense InvestmentIncomeInvestmentExpense	15300000	USD
	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	3600000	USD
CY2021Q2	us-gaap	Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNetAvailableforsaleSecurities	1000000.0	USD
CY2020Q2	us-gaap	Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNetAvailableforsaleSecurities	5400000	USD
	us-gaap	Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNetAvailableforsaleSecurities	9300000	USD
	us-gaap	Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNetAvailableforsaleSecurities	59300000	USD
CY2021Q2	unm	Financing Receivables Allowance For Credit Losses Period Increase Decrease Commercial Mortgage Loans And Unfunded Loan Commitments FinancingReceivablesAllowanceForCreditLossesPeriodIncreaseDecreaseCommercialMortgageLoansAndUnfundedLoanCommitments	100000	USD
CY2021Q2	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	-100000	USD
CY2021Q2	us-gaap	Gain Loss On Investments GainLossOnInvestments	900000	USD
	unm	Notional Amount Of Derivatives Additions NotionalAmountOfDerivativesAdditions	52000000.0	USD
CY2021Q2	unm	Notional Amount Of Derivatives Foreign Currency NotionalAmountOfDerivativesForeignCurrency	0	USD
	unm	Notional Amount Of Derivatives Terminations NotionalAmountOfDerivativesTerminations	288700000	USD
	unm	Notional Amount Of Derivatives Foreign Currency NotionalAmountOfDerivativesForeignCurrency	200000	USD
CY2021Q2	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	919100000	USD
	us-gaap	Interest Rate Cash Flow Hedge Gain Loss Reclassified To Earnings Net InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet	600000	USD
	us-gaap	Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths	55800000	USD
CY2021Q2	us-gaap	Gain Loss From Components Excluded From Assessment Of Fair Value Hedge Effectiveness Net GainLossFromComponentsExcludedFromAssessmentOfFairValueHedgeEffectivenessNet	17100000	USD
	us-gaap	Gain Loss From Components Excluded From Assessment Of Fair Value Hedge Effectiveness Net GainLossFromComponentsExcludedFromAssessmentOfFairValueHedgeEffectivenessNet	10200000	USD
CY2020Q2	us-gaap	Gain Loss From Components Excluded From Assessment Of Fair Value Hedge Effectiveness Net GainLossFromComponentsExcludedFromAssessmentOfFairValueHedgeEffectivenessNet	-4500000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	85500000	USD
CY2021Q2	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	6900000	USD
CY2020Q1	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	-217100000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	551500000	USD
CY2020Q2	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	7200000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	544300000	USD
CY2020Q2	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	327200000	USD
CY2020Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	374200000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	289900000	USD
CY2020Q2	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	327200000	USD
	us-gaap	Schedule Of Liability For Unpaid Claims And Claims Adjustment Expense ScheduleOfLiabilityForUnpaidClaimsAndClaimsAdjustmentExpense	<div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Changes in the liability for unpaid claims and claim adjustment expenses are as follows: </span></div><div><span><br/></span></div><div style="text-align:center"><table style="border-collapse:collapse;display:inline-table;vertical-align:top;width:100.000%"><tr><td style="width:1.0%"/><td style="width:69.514%"/><td style="width:0.1%"/><td style="width:1.0%"/><td style="width:12.496%"/><td style="width:0.1%"/><td style="width:0.1%"/><td style="width:1.992%"/><td style="width:0.1%"/><td style="width:1.0%"/><td style="width:12.498%"/><td style="width:0.1%"/></tr><tr><td colspan="3" style="padding:0 1pt"/><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">2021</span></td><td colspan="3" style="padding:0 1pt"/><td colspan="3" style="border-bottom:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">2020</span></td></tr><tr><td colspan="3" style="padding:0 1pt"/><td colspan="9" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(in millions of dollars)</span></td></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:100%">Balance at January 1</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">24,180.2 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"/><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">23,076.7 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%"> Less Reinsurance Recoverable</span></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">8,378.9 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">2,246.8 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Net Balance at January 1</span></td><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">15,801.3 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">20,829.9 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr style="height:14pt"><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Incurred Related to</span></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%"> Current Year</span></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">3,461.0 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">3,187.2 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%"> Prior Years</span></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%"> Interest</span></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">359.2 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">528.5 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%"> All Other Incurred</span></td><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(217.3)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(270.5)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%"> Foreign Currency</span></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">25.0 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(130.2)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Total Incurred</span></td><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">3,627.9 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">3,315.0 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr style="height:14pt"><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Paid Related to</span></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%"> Current Year</span></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(1,151.3)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(1,015.9)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%"> Prior Years</span></td><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(2,215.8)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(2,546.6)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Total Paid</span></td><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(3,367.1)</span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(3,562.5)</span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr style="height:14pt"><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Reserves Ceded Pursuant to Reinsurance Transaction</span></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(990.0)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">— </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr style="height:14pt"><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Net Balance at June 30</span></div></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">15,072.1 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">20,582.4 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%"> Plus Reinsurance Recoverable</span></td><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">9,042.2 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">2,260.2 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:100%">Balance at June 30</span></div></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">24,114.3 </span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">22,842.6 </span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr></table></div>
CY2020Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	24180200000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	3187200000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	1151300000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	1015900000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	2215800000	USD
CY2021Q2	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	24114300000	USD
CY2021Q2	us-gaap	Operating Lease Impairment Loss OperatingLeaseImpairmentLoss	13900000	USD
CY2021Q2	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	769300	shares
CY2021Q2	unm	Outstanding Restricted Stock And Stock Success Unit Grant Prices Upper Limit OutstandingRestrictedStockAndStockSuccessUnitGrantPricesUpperLimit	49.31
CY2021Q2	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	300000	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	900000	shares
CY2020Q2	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	1800000	shares
	us-gaap	Income Tax Expense Benefit Continuing Operations Adjustment Of Deferred Tax Asset Liability IncomeTaxExpenseBenefitContinuingOperationsAdjustmentOfDeferredTaxAssetLiability	24200000	USD
CY2021Q1	us-gaap	Premiums Receivable Allowance For Doubtful Accounts PremiumsReceivableAllowanceForDoubtfulAccounts	33700000	USD
CY2021Q1	us-gaap	Premiums Receivable Gross PremiumsReceivableGross	602900000	USD
CY2020Q1	us-gaap	Premiums Receivable Allowance For Doubtful Accounts PremiumsReceivableAllowanceForDoubtfulAccounts	32600000	USD
CY2020Q1	us-gaap	Premiums Receivable Gross PremiumsReceivableGross	607200000	USD
CY2020Q1	us-gaap	Premiums Receivable Gross PremiumsReceivableGross	543000000.0	USD
CY2020Q2	us-gaap	Premium Receivable Credit Loss Expense Reversal PremiumReceivableCreditLossExpenseReversal	14900000	USD
	us-gaap	Premium Receivable Credit Loss Expense Reversal PremiumReceivableCreditLossExpenseReversal	23700000	USD
CY2021Q2	us-gaap	Operating Lease Impairment Loss OperatingLeaseImpairmentLoss	13900000	USD
	us-gaap	Operating Lease Impairment Loss OperatingLeaseImpairmentLoss	12700000	USD

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2021 Q3 Form 10-Q Financial Statement

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2021 Q3 Form 10-Q Financial Statement

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