$elv 2018 Q2 10-Q

Concept	2018 Q2	2017 Q2
Revenue	$22.94B	$22.41B
YoY Change	2.4%	4.43%
Cost Of Revenue	$0.00	$17.92B
YoY Change	-100.0%	6.62%
Gross Profit	$22.94B	$4.490B
YoY Change	411.02%	-3.47%
Gross Profit Margin	100.0%	20.04%
Selling, General & Admin	$3.428B	$3.054B
YoY Change	12.25%	2.85%
% of Gross Profit	14.94%	68.02%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$286.0M	$219.0M
YoY Change	30.59%	-3.1%
% of Gross Profit	1.25%	4.88%
Operating Expenses	$3.428B	$3.054B
YoY Change	12.25%	2.85%
Operating Profit	$1.559B	$1.227B
YoY Change	27.06%	-18.21%
Interest Expense	$192.0M	$189.9M
YoY Change	1.11%	2.26%
% of Operating Profit	12.32%	15.48%
Other Income/Expense, Net
YoY Change
Pretax Income	$1.504B	$1.205B
YoY Change	24.81%	-16.8%
Income Tax	$450.0M	$350.4M
% Of Pretax Income	29.92%	29.08%
Net Earnings	$1.054B	$855.0M
YoY Change	23.27%	9.53%
Net Earnings / Revenue	4.59%	3.82%
Basic Earnings Per Share	$4.07	$3.23
Diluted Earnings Per Share	$3.98	$3.16
COMMON SHARES
Basic Shares Outstanding	258.7M shares	264.6M shares
Diluted Shares Outstanding	264.5M shares	270.8M shares

Concept	2018 Q2	2017 Q2
SHORT-TERM ASSETS
Cash & Short-Term Investments	$21.76B	$23.51B
YoY Change	-7.43%	16.7%
Cash & Equivalents	$4.682B	$4.561B
Short-Term Investments	$17.08B	$18.95B
Other Short-Term Assets	$3.106B	$1.775B
YoY Change	75.03%	-14.82%
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets	$37.37B	$37.13B
YoY Change	0.65%	12.66%
LONG-TERM ASSETS
Property, Plant & Equipment	$2.392B	$1.976B
YoY Change	21.08%	-0.71%
Goodwill	$20.41B	$17.56B
YoY Change	16.25%	-0.01%
Intangibles	$9.224B	$7.882B
YoY Change	17.02%	-2.2%
Long-Term Investments	$23.56B	$23.70B
YoY Change	-0.61%	3.73%
Other Assets	$950.4M	$778.4M
YoY Change	22.1%	-9.72%
Total Long-Term Assets	$37.00B	$31.11B
YoY Change	18.94%	0.01%
TOTAL ASSETS
Total Short-Term Assets	$37.37B	$37.13B
Total Long-Term Assets	$37.00B	$31.11B
Total Assets	$74.37B	$68.24B
YoY Change	8.98%	6.52%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$5.931B	$3.816B
YoY Change	55.42%	-10.67%
Accrued Expenses
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$1.120B	$580.0M
YoY Change	93.1%	31.82%
Long-Term Debt Due	$650.2M	$624.4M
YoY Change	4.13%	-32.71%
Total Short-Term Liabilities	$24.51B	$22.57B
YoY Change	8.59%	8.41%
LONG-TERM LIABILITIES
Long-Term Debt	$17.52B	$15.09B
YoY Change	16.09%	6.24%
Other Long-Term Liabilities	$1.074B	$898.3M
YoY Change	19.6%	-39.3%
Total Long-Term Liabilities	$18.59B	$15.99B
YoY Change	16.29%	1.94%
TOTAL LIABILITIES
Total Short-Term Liabilities	$24.51B	$22.57B
Total Long-Term Liabilities	$18.59B	$15.99B
Total Liabilities	$45.64B	$41.81B
YoY Change	9.18%	4.96%
SHAREHOLDERS EQUITY
Retained Earnings	$19.76B	$17.67B
YoY Change	11.83%	10.98%
Common Stock	$2.600M	$2.600M
YoY Change	0.0%	0.0%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$28.73B	$26.43B
YoY Change
Total Liabilities & Shareholders Equity	$74.37B	$68.24B
YoY Change	8.98%	6.52%

Concept	2018 Q2	2017 Q2
OPERATING ACTIVITIES
Net Income	$1.054B	$855.0M
YoY Change	23.27%	9.53%
Depreciation, Depletion And Amortization	$286.0M	$219.0M
YoY Change	30.59%	-3.1%
Cash From Operating Activities	$542.0M	$393.0M
YoY Change	37.91%	-41.26%
INVESTING ACTIVITIES
Capital Expenditures	-$315.0M	-$170.0M
YoY Change	85.29%	27.82%
Acquisitions
YoY Change
Other Investing Activities	-$464.0M	-$872.0M
YoY Change	-46.79%	376.5%
Cash From Investing Activities	-$778.0M	-$1.042B
YoY Change	-25.34%	228.71%
FINANCING ACTIVITIES
Cash Dividend Paid	$196.0M	$172.0M
YoY Change	13.95%	0.64%
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	289.0M	-1.564B
YoY Change	-118.48%	252.25%
NET CHANGE
Cash From Operating Activities	542.0M	393.0M
Cash From Investing Activities	-778.0M	-1.042B
Cash From Financing Activities	289.0M	-1.564B
Net Change In Cash	53.00M	-2.213B
YoY Change	-102.39%	2305.43%
FREE CASH FLOW
Cash From Operating Activities	$542.0M	$393.0M
Capital Expenditures	-$315.0M	-$170.0M
Free Cash Flow	$857.0M	$563.0M
YoY Change	52.22%	-29.8%

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2018Q2	antm	Available For Sale Securities Debt Maturities Amortized Cost Noncurrent AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostNoncurrent	489700000	USD
CY2017Q2	antm	Available For Sale Securities Other Than Temporary Impairments In Accumulated Other Comprehensive Income Deferred Tax Liability Asset AvailableForSaleSecuritiesOtherThanTemporaryImpairmentsInAccumulatedOtherComprehensiveIncomeDeferredTaxLiabilityAsset	100000	USD
CY2018Q2	antm	Available For Sale Securities Other Than Temporary Impairments In Accumulated Other Comprehensive Income Deferred Tax Liability Asset AvailableForSaleSecuritiesOtherThanTemporaryImpairmentsInAccumulatedOtherComprehensiveIncomeDeferredTaxLiabilityAsset	0	USD
CY2017Q2	antm	Cash Flow Hedging Instruments Accumulated Other Comprehensive Income Net Deferred Tax Asset CashFlowHedgingInstrumentsAccumulatedOtherComprehensiveIncomeNetDeferredTaxAsset	124600000	USD
CY2018Q2	antm	Cash Flow Hedging Instruments Accumulated Other Comprehensive Income Net Deferred Tax Asset CashFlowHedgingInstrumentsAccumulatedOtherComprehensiveIncomeNetDeferredTaxAsset	66900000	USD
CY2017Q2	antm	Deferred Net Actuarial Gain Loss Postretirement Benefits DeferredNetActuarialGainLossPostretirementBenefits	-140900000	USD
CY2018Q2	antm	Deferred Net Actuarial Gain Loss Postretirement Benefits DeferredNetActuarialGainLossPostretirementBenefits	-75700000	USD
CY2017Q2	antm	Accumulated Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Before Tax AccumulatedOtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	-3100000	USD
CY2018Q2	antm	Accumulated Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Before Tax AccumulatedOtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	-2100000	USD
CY2017Q2	antm	Available For Sale Securities Accumulated Other Comprehensive Income Net Deferred Tax Liability AvailableForSaleSecuritiesAccumulatedOtherComprehensiveIncomeNetDeferredTaxLiability	-304000000	USD
CY2018Q2	antm	Available For Sale Securities Accumulated Other Comprehensive Income Net Deferred Tax Liability AvailableForSaleSecuritiesAccumulatedOtherComprehensiveIncomeNetDeferredTaxLiability	15400000	USD
CY2017Q4	antm	Available For Sale Securities Debt Maturities Amortized Cost Noncurrent AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostNoncurrent	556000000	USD
CY2017Q2	antm	Deferred Prior Service Cost Credit Postretirement Benefit Plans DeferredPriorServiceCostCreditPostretirementBenefitPlans	52900000	USD
CY2018Q2	antm	Deferred Prior Service Cost Credit Postretirement Benefit Plans DeferredPriorServiceCostCreditPostretirementBenefitPlans	39800000	USD
CY2017Q2	antm	Defined Benefit Plan Accumulated Other Comprehensive Income Adjustments Net Of Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeAdjustmentsNetOfTax	-390300000	USD
CY2018Q2	antm	Defined Benefit Plan Accumulated Other Comprehensive Income Adjustments Net Of Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeAdjustmentsNetOfTax	-445000000	USD
CY2017Q2	antm	Defined Benefit Plan Accumulated Other Comprehensive Income Net Deferred Tax Asset DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetDeferredTaxAsset	-251600000	USD
CY2018Q2	antm	Defined Benefit Plan Accumulated Other Comprehensive Income Net Deferred Tax Asset DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetDeferredTaxAsset	-155500000	USD
CY2017Q4	antm	Equity Securities EquitySecurities	3632000000	USD
CY2018Q2	antm	Equity Securities EquitySecurities	2468200000	USD
CY2017Q4	antm	Equity Securities Current EquitySecuritiesCurrent	3599200000	USD
CY2018Q2	antm	Equity Securities Current EquitySecuritiesCurrent	2435300000	USD
CY2017Q4	antm	Equitysecurities Longterm EquitysecuritiesLongterm	32800000	USD
CY2018Q2	antm	Equitysecurities Longterm EquitysecuritiesLongterm	32900000	USD
CY2018Q2	antm	Gross Premium Tax Rate GrossPremiumTaxRate	0.0235
CY2017Q4	antm	Liability For Future Policy Benefits Current LiabilityForFuturePolicyBenefitsCurrent	69900000	USD
	dei	Document Period End Date DocumentPeriodEndDate	2018-06-30
CY2018Q2	antm	Liability For Future Policy Benefits Current LiabilityForFuturePolicyBenefitsCurrent	72100000	USD
CY2018Q2	antm	Liability For Unpaid Claims And Claims Adjustment Expense Purchase Adjustments LiabilityForUnpaidClaimsAndClaimsAdjustmentExpensePurchaseAdjustments	199200000	USD
	dei	Document Type DocumentType	10-Q
CY2017Q4	antm	Increase In Stock Repurchase Program Authorization IncreaseInStockRepurchaseProgramAuthorization	5000000000	USD
CY2018Q2	antm	Merger Agreement Termination Fee MergerAgreementTerminationFee	1850000000	USD
	antm	Net Adjustment To Additional Paid In Capital For Equity Hedge NetAdjustmentToAdditionalPaidInCapitalForEquityHedge	300000	USD
CY2017Q2	antm	Netrealizedgainslossesonfinancialinstruments Netrealizedgainslossesonfinancialinstruments	16200000	USD
	antm	Netrealizedgainslossesonfinancialinstruments Netrealizedgainslossesonfinancialinstruments	23500000	USD
CY2018Q2	antm	Netrealizedgainslossesonfinancialinstruments Netrealizedgainslossesonfinancialinstruments	4000000	USD
	antm	Netrealizedgainslossesonfinancialinstruments Netrealizedgainslossesonfinancialinstruments	-22100000	USD
CY2018Q2	antm	Number Of Counties In State Of Kansas Company Does Not Serve NumberOfCountiesInStateOfKansasCompanyDoesNotServe	30	county
CY2018Q2	antm	Number Of Medical Members NumberOfMedicalMembers	39500000	medical_member
CY2018Q2	antm	Numberofstatesinwhichcustomersareservedthroughsubsidiaries Numberofstatesinwhichcustomersareservedthroughsubsidiaries	25	states
CY2017Q2	antm	Other Net Change In Unrecognized Periodic Benefit Costs For Defined Benefit Pension And Postretirement Benefit Plans Tax Benefit Expense OtherNetChangeInUnrecognizedPeriodicBenefitCostsForDefinedBenefitPensionAndPostretirementBenefitPlansTaxBenefitExpense	-2900000	USD
	antm	Other Net Change In Unrecognized Periodic Benefit Costs For Defined Benefit Pension And Postretirement Benefit Plans Tax Benefit Expense OtherNetChangeInUnrecognizedPeriodicBenefitCostsForDefinedBenefitPensionAndPostretirementBenefitPlansTaxBenefitExpense	-5200000	USD
CY2018Q2	antm	Other Net Change In Unrecognized Periodic Benefit Costs For Defined Benefit Pension And Postretirement Benefit Plans Tax Benefit Expense OtherNetChangeInUnrecognizedPeriodicBenefitCostsForDefinedBenefitPensionAndPostretirementBenefitPlansTaxBenefitExpense	-2700000	USD
	antm	Other Net Change In Unrecognized Periodic Benefit Costs For Defined Benefit Pension And Postretirement Benefit Plans Tax Benefit Expense OtherNetChangeInUnrecognizedPeriodicBenefitCostsForDefinedBenefitPensionAndPostretirementBenefitPlansTaxBenefitExpense	-5300000	USD
	antm	Payments For Proceeds From Financing Derivatives PaymentsForProceedsFromFinancingDerivatives	128400000	USD
	antm	Payments For Proceeds From Financing Derivatives PaymentsForProceedsFromFinancingDerivatives	-21900000	USD
	antm	Paymentstoacquireequitysecurities Paymentstoacquireequitysecurities	506000000	USD
	antm	Paymentstoacquireequitysecurities Paymentstoacquireequitysecurities	657900000	USD
	antm	Percentageofrevenuessubjecttonewrevenueguidanceunder Asc606 PercentageofrevenuessubjecttonewrevenueguidanceunderASC606	0.060
	antm	Potentially Dilutive Restricted Stock Units Contingent On Operating Results PotentiallyDilutiveRestrictedStockUnitsContingentOnOperatingResults	100000	shares
	antm	Potentially Dilutive Restricted Stock Units Contingent On Operating Results PotentiallyDilutiveRestrictedStockUnitsContingentOnOperatingResults	300000	shares
	antm	Proceedsfromsaleofequitysecurities Proceedsfromsaleofequitysecurities	214700000	USD
	antm	Proceedsfromsaleofequitysecurities Proceedsfromsaleofequitysecurities	1777100000	USD
	antm	Reclassificationofstrandedtaxeffectsresultingfromthe Tax Cutsand Jobs Act ReclassificationofstrandedtaxeffectsresultingfromtheTaxCutsandJobsAct	91300000	USD
CY2017	antm	Securities Lending Transactions Initial Collateral Percentage Value SecuritiesLendingTransactionsInitialCollateralPercentageValue	1.02
	antm	Securities Lending Transactions Initial Collateral Percentage Value SecuritiesLendingTransactionsInitialCollateralPercentageValue	1.02
CY2017	antm	Securities Lending Transactions Ratioof Fair Valueof Collateral Held To Securities On Loan SecuritiesLendingTransactionsRatioofFairValueofCollateralHeldToSecuritiesOnLoan	1.04
	antm	Securities Lending Transactions Ratioof Fair Valueof Collateral Held To Securities On Loan SecuritiesLendingTransactionsRatioofFairValueofCollateralHeldToSecuritiesOnLoan	1.02
CY2017Q4	antm	Self Funded Receivables Net SelfFundedReceivablesNet	2579700000	USD
CY2018Q2	antm	Self Funded Receivables Net SelfFundedReceivablesNet	2650000000	USD
CY2017Q4	antm	Selffunded Receivables Allowance For Doubtful Accounts SelffundedReceivablesAllowanceForDoubtfulAccounts	153200000	USD
CY2018Q2	antm	Selffunded Receivables Allowance For Doubtful Accounts SelffundedReceivablesAllowanceForDoubtfulAccounts	52300000	USD
	antm	Stock Repurchased And Retired During Period Average Price StockRepurchasedAndRetiredDuringPeriodAveragePrice	180.37
	antm	Stock Repurchased And Retired During Period Average Price StockRepurchasedAndRetiredDuringPeriodAveragePrice	231.61
	dei	Amendment Flag AmendmentFlag	false
	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	Q2
	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2018
	dei	Entity Central Index Key EntityCentralIndexKey	0001156039
CY2018Q2	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	260132949	shares
CY2018Q3	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	259953678	shares
	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
	dei	Entity Registrant Name EntityRegistrantName	Anthem, Inc.
	dei	Trading Symbol TradingSymbol	ANTM
CY2017Q4	invest	Derivative Notional Amount DerivativeNotionalAmount	2048100000	USD
CY2018Q2	invest	Derivative Notional Amount DerivativeNotionalAmount	1868800000	USD
CY2017Q4	us-gaap	Accounts Payable And Accrued Liabilities Current AccountsPayableAndAccruedLiabilitiesCurrent	5024400000	USD
CY2018Q2	us-gaap	Accounts Payable And Accrued Liabilities Current AccountsPayableAndAccruedLiabilitiesCurrent	5931400000	USD
CY2017Q4	us-gaap	Accrued Investment Income Receivable AccruedInvestmentIncomeReceivable	162500000	USD
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CY2017Q2	us-gaap	Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	542300000	USD
CY2018Q2	us-gaap	Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-57900000	USD
CY2017Q2	us-gaap	Accumulated Other Comprehensive Income Loss Cumulative Changes In Net Gain Loss From Cash Flow Hedges Effect Net Of Tax AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax	-231200000	USD
CY2018Q2	us-gaap	Accumulated Other Comprehensive Income Loss Cumulative Changes In Net Gain Loss From Cash Flow Hedges Effect Net Of Tax AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax	-251600000	USD
CY2017Q2	us-gaap	Accumulated Other Comprehensive Income Loss Defined Benefit Pension And Other Postretirement Plans Net Of Tax AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax	53600000	USD
CY2018Q2	us-gaap	Accumulated Other Comprehensive Income Loss Defined Benefit Pension And Other Postretirement Plans Net Of Tax AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax	26600000	USD
CY2017Q2	us-gaap	Accumulated Other Comprehensive Income Loss Foreign Currency Translation Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax	-2000000	USD
CY2018Q2	us-gaap	Accumulated Other Comprehensive Income Loss Foreign Currency Translation Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax	-1700000	USD
CY2017Q2	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-134900000	USD
CY2017Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-101500000	USD
CY2018Q2	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-782800000	USD
CY2017Q2	us-gaap	Accumulated Other Comprehensive Income Loss Other Than Temporary Impairment Not Credit Loss Net Of Tax Availableforsale Debt Securities AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxAvailableforsaleDebtSecurities	200000	USD
CY2018Q2	us-gaap	Accumulated Other Comprehensive Income Loss Other Than Temporary Impairment Not Credit Loss Net Of Tax Availableforsale Debt Securities AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxAvailableforsaleDebtSecurities	0	USD
CY2017Q2	us-gaap	Accumulated Other Comprehensive Income Loss Other Than Temporary Impairment Not Credit Loss Net Of Tax Debt Securities AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities	100000	USD
CY2018Q2	us-gaap	Accumulated Other Comprehensive Income Loss Other Than Temporary Impairment Not Credit Loss Net Of Tax Debt Securities AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities	0	USD
CY2017Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	8547400000	USD
CY2018Q2	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	9747900000	USD
	us-gaap	Adjustment For Amortization AdjustmentForAmortization	385000000	USD
	us-gaap	Adjustment For Amortization AdjustmentForAmortization	495100000	USD
	us-gaap	Adjustments To Additional Paid In Capital Equity Component Of Convertible Debt Subsequent Adjustments AdjustmentsToAdditionalPaidInCapitalEquityComponentOfConvertibleDebtSubsequentAdjustments	-1100000	USD
	us-gaap	Adjustments To Additional Paid In Capital Equity Component Of Convertible Debt Subsequent Adjustments AdjustmentsToAdditionalPaidInCapitalEquityComponentOfConvertibleDebtSubsequentAdjustments	-30500000	USD
CY2017Q2	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	40600000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	82400000	USD
CY2018Q2	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	93600000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	173100000	USD
CY2017Q2	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	1000000	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	700000	shares
CY2018Q2	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	800000	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	500000	shares
CY2017Q4	us-gaap	Assets Assets	70540000000	USD
CY2018Q2	us-gaap	Assets Assets	74367400000	USD
CY2017Q4	us-gaap	Assets Current AssetsCurrent	36262800000	USD
CY2018Q2	us-gaap	Assets Current AssetsCurrent	37370400000	USD
CY2017Q4	us-gaap	Assets Fair Value Disclosure Recurring AssetsFairValueDisclosureRecurring	24001900000	USD
CY2018Q2	us-gaap	Assets Fair Value Disclosure Recurring AssetsFairValueDisclosureRecurring	23323700000	USD
CY2017Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	17054500000	USD
CY2018Q2	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	17152700000	USD
CY2017Q2	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	941600000	USD
CY2018Q2	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	199700000	USD
CY2017Q2	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Gain Loss Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainLossBeforeTax	846300000	USD
CY2018Q2	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Gain Loss Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainLossBeforeTax	-73300000	USD
CY2017Q2	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	95300000	USD
CY2018Q2	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	273000000	USD
CY2017Q4	us-gaap	Available For Sale Securities Debt Securities Current AvailableForSaleSecuritiesDebtSecuritiesCurrent	17377300000	USD
CY2018Q2	us-gaap	Available For Sale Securities Debt Securities Current AvailableForSaleSecuritiesDebtSecuritiesCurrent	17081600000	USD
CY2017Q4	us-gaap	Available For Sale Securities Debt Securities Noncurrent AvailableForSaleSecuritiesDebtSecuritiesNoncurrent	560800000	USD
CY2018Q2	us-gaap	Available For Sale Securities Debt Securities Noncurrent AvailableForSaleSecuritiesDebtSecuritiesNoncurrent	487500000	USD
CY2017Q2	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	41200000	USD
	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	86700000	USD
CY2018Q2	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	30900000	USD
	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	60600000	USD
CY2017Q2	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	16600000	USD
	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	40300000	USD
CY2018Q2	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	32600000	USD
	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	69000000	USD
CY2017Q2	us-gaap	Available For Sale Securities Income Tax Expense On Change In Unrealized Holding Gain Or Loss AvailableForSaleSecuritiesIncomeTaxExpenseOnChangeInUnrealizedHoldingGainOrLoss	-67000000	USD
	us-gaap	Available For Sale Securities Income Tax Expense On Change In Unrealized Holding Gain Or Loss AvailableForSaleSecuritiesIncomeTaxExpenseOnChangeInUnrealizedHoldingGainOrLoss	-113300000	USD
CY2018Q2	us-gaap	Available For Sale Securities Income Tax Expense On Change In Unrealized Holding Gain Or Loss AvailableForSaleSecuritiesIncomeTaxExpenseOnChangeInUnrealizedHoldingGainOrLoss	21400000	USD
	us-gaap	Available For Sale Securities Income Tax Expense On Change In Unrealized Holding Gain Or Loss AvailableForSaleSecuritiesIncomeTaxExpenseOnChangeInUnrealizedHoldingGainOrLoss	98500000	USD
CY2017Q2	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	21201500000	USD
	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	42212400000	USD
CY2018Q2	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	21440200000	USD
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CY2016Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	4075300000	USD
CY2017Q2	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	4561200000	USD
CY2017Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	3608900000	USD
CY2018Q2	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	4682000000	USD
CY2017Q4	us-gaap	Cash And Cash Equivalents Fair Value Disclosure CashAndCashEquivalentsFairValueDisclosure	1956400000	USD
CY2018Q2	us-gaap	Cash And Cash Equivalents Fair Value Disclosure CashAndCashEquivalentsFairValueDisclosure	2626200000	USD
	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	485900000	USD
	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	1073100000	USD
CY2016Q4	us-gaap	Ceded Premiums Payable CededPremiumsPayable	539100000	USD
CY2017Q2	us-gaap	Ceded Premiums Payable CededPremiumsPayable	491800000	USD
CY2017Q4	us-gaap	Ceded Premiums Payable CededPremiumsPayable	104900000	USD
CY2018Q2	us-gaap	Ceded Premiums Payable CededPremiumsPayable	34800000	USD
CY2017Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2018Q2	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2017Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.65
CY2017Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.65
CY2018Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.75
CY2018Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.75
CY2017Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.65
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.30
CY2018Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.75
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.50
CY2017Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2018Q2	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2017Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	900000000	shares
CY2018Q2	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	900000000	shares
CY2017Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	256084913	shares
CY2018Q2	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	260132949	shares
CY2017Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	256084913	shares
CY2018Q2	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	260132949	shares
CY2017Q4	us-gaap	Common Stock Value CommonStockValue	2600000	USD
CY2018Q2	us-gaap	Common Stock Value CommonStockValue	2600000	USD
CY2017Q2	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	882200000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	1998200000	USD
CY2018Q2	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	991200000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	2096100000	USD
CY2018Q1	us-gaap	Cumulative Effect Of New Accounting Principle In Period Of Adoption CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	320200000	USD
	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-209900000	USD
	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	1900000	USD
CY2017Q2	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits	34400000	USD
CY2018Q2	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits	9300000	USD
CY2017Q2	us-gaap	Deferred Tax Assets Unrealized Currency Losses DeferredTaxAssetsUnrealizedCurrencyLosses	1100000	USD
CY2018Q2	us-gaap	Deferred Tax Assets Unrealized Currency Losses DeferredTaxAssetsUnrealizedCurrencyLosses	400000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Noncurrent DeferredTaxLiabilitiesNoncurrent	1726500000	USD
CY2018Q2	us-gaap	Deferred Tax Liabilities Noncurrent DeferredTaxLiabilitiesNoncurrent	1902200000	USD
CY2017Q2	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Net Gains Losses Before Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax	-641200000	USD
CY2018Q2	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Net Gains Losses Before Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax	-599500000	USD
CY2017Q2	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Net Prior Service Cost Credit Before Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax	700000	USD
CY2018Q2	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Net Prior Service Cost Credit Before Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax	1000000	USD
CY2017Q4	us-gaap	Deposits Received For Securities Loaned At Carrying Value DepositsReceivedForSecuritiesLoanedAtCarryingValue	454400000	USD
CY2018Q2	us-gaap	Deposits Received For Securities Loaned At Carrying Value DepositsReceivedForSecuritiesLoanedAtCarryingValue	624300000	USD
	us-gaap	Depreciation Depreciation	54500000	USD
	us-gaap	Depreciation Depreciation	60600000	USD
CY2017Q4	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	1600000	USD
CY2018Q2	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	11800000	USD
CY2017Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	3100000	USD
CY2018Q2	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	11800000	USD
CY2017Q4	us-gaap	Derivative Fair Value Of Derivative Asset Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral	1500000	USD
CY2018Q2	us-gaap	Derivative Fair Value Of Derivative Asset Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral	0	USD
CY2017Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	21500000	USD
CY2018Q2	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	17800000	USD
CY2017Q4	us-gaap	Derivative Fair Value Of Derivative Liability Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral	19900000	USD
CY2018Q2	us-gaap	Derivative Fair Value Of Derivative Liability Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral	6000000	USD
CY2017Q2	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	-14600000	USD
CY2017Q4	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	1600000	USD
CY2018Q2	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	11800000	USD
	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	-24900000	USD
CY2018Q2	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	19400000	USD
	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	19300000	USD
CY2017Q4	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	11500000	USD
CY2018Q2	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	9000000	USD
CY2017Q1	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2017-03-24
CY2017Q2	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2017-06-23
CY2018Q1	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2018-03-23
CY2018Q2	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2018-06-25
	us-gaap	Dividends Common Stock DividendsCommonStock	344800000	USD
	us-gaap	Dividends Common Stock DividendsCommonStock	396100000	USD
CY2017Q1	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2017-02-22
CY2017Q2	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2017-04-27
CY2018Q1	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2018-01-30
CY2018Q2	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2018-04-24
CY2017Q1	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2017-03-10
CY2017Q2	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2017-06-09
CY2018Q1	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2018-03-09
CY2018Q2	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2018-06-08
CY2017Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.23
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	7.05
CY2018Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.07
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	9.20
CY2017Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.16
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	6.89
CY2018Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.98
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	8.97
	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	2900000	USD
	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	-400000	USD
CY2017Q2	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.291
	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.314
CY2018Q2	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.299
	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.280
CY2017Q2	us-gaap	Fair Value Assets Measured On Recurring Basis Change In Unrealized Gain Loss FairValueAssetsMeasuredOnRecurringBasisChangeInUnrealizedGainLoss	-900000	USD
	us-gaap	Fair Value Assets Measured On Recurring Basis Change In Unrealized Gain Loss FairValueAssetsMeasuredOnRecurringBasisChangeInUnrealizedGainLoss	-2600000	USD
CY2018Q2	us-gaap	Fair Value Assets Measured On Recurring Basis Change In Unrealized Gain Loss FairValueAssetsMeasuredOnRecurringBasisChangeInUnrealizedGainLoss	7400000	USD
	us-gaap	Fair Value Assets Measured On Recurring Basis Change In Unrealized Gain Loss FairValueAssetsMeasuredOnRecurringBasisChangeInUnrealizedGainLoss	37600000	USD
CY2017Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	400000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	-600000	USD
CY2018Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	8100000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	-230900000	USD
CY2017Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	600000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	3900000	USD
CY2018Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	-2800000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	-2400000	USD
CY2017Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases	68000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases	149800000	USD
CY2018Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases	53400000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases	329000000	USD
CY2017Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales	12000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales	46500000	USD
CY2018Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales	11600000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales	16100000	USD
CY2017Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements	16800000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements	37000000	USD
CY2018Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements	24000000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements	31100000	USD
CY2017Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	6300000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	15800000	USD
CY2018Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	41800000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	62600000	USD
CY2017Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	15200000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	46400000	USD
CY2018Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	600000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	2000000	USD
CY2016Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	481400000	USD
CY2017Q1	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	489100000	USD
CY2017Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	520400000	USD
CY2017Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	537500000	USD
CY2018Q1	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	582300000	USD
CY2018Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	646600000	USD
	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-400000	USD
	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-500000	USD
CY2017Q2	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	0	USD
	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	0	USD
CY2018Q2	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	900000	USD
	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-18200000	USD
CY2017Q2	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	2708300000	USD
	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	5551000000	USD
CY2018Q2	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	3104400000	USD
	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	6214700000	USD
CY2017Q4	us-gaap	Goodwill Goodwill	19231200000	USD
CY2018Q2	us-gaap	Goodwill Goodwill	20414500000	USD
CY2017Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	1205700000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	2720700000	USD
CY2018Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	1503500000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	3283800000	USD
CY2017Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	1205700000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	2720700000	USD
CY2018Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	1503500000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	3283800000	USD
CY2017Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	350400000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	855500000	USD
CY2018Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	450100000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	917900000	USD
CY2018Q2	us-gaap	Income Tax Reconciliation Nondeductible Expense IncomeTaxReconciliationNondeductibleExpense	83600000	USD
	us-gaap	Income Tax Reconciliation Nondeductible Expense IncomeTaxReconciliationNondeductibleExpense	166900000	USD
CY2017Q4	us-gaap	Income Taxes Receivable IncomeTaxesReceivable	341900000	USD
CY2018Q2	us-gaap	Income Taxes Receivable IncomeTaxesReceivable	154500000	USD
	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	-53000000	USD
	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	28800000	USD
	us-gaap	Increase Decrease In Collateral Held Under Securities Lending IncreaseDecreaseInCollateralHeldUnderSecuritiesLending	134800000	USD
	us-gaap	Increase Decrease In Collateral Held Under Securities Lending IncreaseDecreaseInCollateralHeldUnderSecuritiesLending	170000000	USD
	us-gaap	Increase Decrease In Income Taxes Payable Net Of Income Taxes Receivable IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable	281700000	USD
	us-gaap	Increase Decrease In Income Taxes Payable Net Of Income Taxes Receivable IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable	187400000	USD
	us-gaap	Increase Decrease In Insurance Liabilities IncreaseDecreaseInInsuranceLiabilities	254000000	USD
	us-gaap	Increase Decrease In Insurance Liabilities IncreaseDecreaseInInsuranceLiabilities	-609900000	USD
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	322400000	USD
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	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	134700000	USD
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	us-gaap	Increase Decrease In Securities Lending Payable IncreaseDecreaseInSecuritiesLendingPayable	134800000	USD
	us-gaap	Increase Decrease In Securities Lending Payable IncreaseDecreaseInSecuritiesLendingPayable	169900000	USD
	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	22400000	USD
	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	11000000	USD
	us-gaap	Increase Decrease In Unearned Premiums IncreaseDecreaseInUnearnedPremiums	865900000	USD
	us-gaap	Increase Decrease In Unearned Premiums IncreaseDecreaseInUnearnedPremiums	1157600000	USD
CY2017Q2	us-gaap	Insurance Services Revenue InsuranceServicesRevenue	22198000000	USD
	us-gaap	Insurance Services Revenue InsuranceServicesRevenue	44517500000	USD
CY2018Q2	us-gaap	Insurance Services Revenue InsuranceServicesRevenue	22714800000	USD
	us-gaap	Insurance Services Revenue InsuranceServicesRevenue	45057100000	USD
CY2017Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	8368400000	USD
CY2018Q2	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	9224300000	USD
CY2017Q2	us-gaap	Interest Expense InterestExpense	189900000	USD
	us-gaap	Interest Expense InterestExpense	424900000	USD
CY2018Q2	us-gaap	Interest Expense InterestExpense	191700000	USD
	us-gaap	Interest Expense InterestExpense	375900000	USD
CY2017Q4	us-gaap	Liabilities Liabilities	44037100000	USD
CY2018Q2	us-gaap	Liabilities Liabilities	45642400000	USD
CY2017Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	70540000000	USD
CY2018Q2	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	74367400000	USD
CY2017Q4	us-gaap	Liabilities Current LiabilitiesCurrent	23356000000	USD
CY2018Q2	us-gaap	Liability For Future Policy Benefits And Unpaid Claims And Claims Adjustment Expense LiabilityForFuturePolicyBenefitsAndUnpaidClaimsAndClaimsAdjustmentExpense	10627200000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	28540400000	USD
CY2018Q2	us-gaap	Liabilities Current LiabilitiesCurrent	24505700000	USD
CY2017Q4	us-gaap	Liabilities Fair Value Disclosure Recurring LiabilitiesFairValueDisclosureRecurring	21500000	USD
CY2018Q2	us-gaap	Liabilities Fair Value Disclosure Recurring LiabilitiesFairValueDisclosureRecurring	17800000	USD
CY2016Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	7892600000	USD
CY2017Q2	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	7969500000	USD
CY2017Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	7991500000	USD
CY2018Q2	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	7545300000	USD
CY2017Q4	us-gaap	Liability For Future Policy Benefits LiabilityForFuturePolicyBenefits	647300000	USD
CY2018Q2	us-gaap	Liability For Future Policy Benefits LiabilityForFuturePolicyBenefits	644700000	USD
CY2017Q4	us-gaap	Liability For Future Policy Benefits And Unpaid Claims And Claims Adjustment Expense LiabilityForFuturePolicyBenefitsAndUnpaidClaimsAndClaimsAdjustmentExpense	11011700000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	28146400000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	6070900000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	6358200000	USD
CY2017Q2	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	17561600000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	34735500000	USD
CY2018Q2	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	17303300000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	33929300000	USD
CY2016Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	7353500000	USD
CY2017Q2	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	7477700000	USD
CY2017Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	7886600000	USD
CY2018Q2	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	7510500000	USD
	us-gaap	Litigation Settlement Amount Awarded To Other Party LitigationSettlementAmountAwardedToOtherParty	115000000	USD
CY2017Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	1274600000	USD
CY2018Q2	us-gaap	Long Term Debt Current LongTermDebtCurrent	650200000	USD
CY2017Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	17382200000	USD
CY2018Q2	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	17515400000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-329500000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-339400000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-2268800000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1344200000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	3081300000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	2757100000	USD
CY2017Q2	us-gaap	Net Income Loss NetIncomeLoss	855300000	USD
	us-gaap	Net Income Loss NetIncomeLoss	1865200000	USD
CY2018Q2	us-gaap	Net Income Loss NetIncomeLoss	1053400000	USD
	us-gaap	Net Income Loss NetIncomeLoss	2365900000	USD
CY2017Q2	us-gaap	Net Investment Income NetInvestmentIncome	200200000	USD
	us-gaap	Net Investment Income NetInvestmentIncome	407400000	USD
CY2018Q2	us-gaap	Net Investment Income NetInvestmentIncome	229300000	USD
	us-gaap	Net Investment Income NetInvestmentIncome	458500000	USD
	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	3	segment
CY2018Q2	us-gaap	Number Of States In Which Entity Operates NumberOfStatesInWhichEntityOperates	50	states
CY2017Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	1227000000	USD
	us-gaap	Operating Income Loss OperatingIncomeLoss	2812400000	USD
CY2018Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	1559000000	USD
	us-gaap	Operating Income Loss OperatingIncomeLoss	3426900000	USD
CY2017Q4	us-gaap	Other Assets Current OtherAssetsCurrent	2249300000	USD
CY2018Q2	us-gaap	Other Assets Current OtherAssetsCurrent	3106100000	USD
CY2017Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	565300000	USD
CY2018Q2	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	950400000	USD
CY2017Q2	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	116200000	USD
	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	210400000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-76800000	USD
	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-333000000	USD
CY2017Q2	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	700000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	2100000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-800000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-400000	USD
CY2017Q2	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	-400000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	-1100000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	-100000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	-400000	USD
CY2017Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	26900000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	133000000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-62200000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-269800000	USD
CY2017Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	26900000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-316700000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-72000000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	133000000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-62200000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-269800000	USD
CY2017Q2	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-4200000	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-8100000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-7700000	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-15400000	USD
CY2017Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	15300000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	29300000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	-4800000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	-16300000	USD
CY2017Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	-8300000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	-15800000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	1300000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	4400000	USD
CY2017Q2	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	-25800000	USD
	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	-72400000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	16600000	USD
	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	79800000	USD
CY2017Q2	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-79800000	USD
	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-62800000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	2900000	USD
	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	31700000	USD
CY2017Q2	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	36600000	USD
	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	33900000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	-700000	USD
	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	-8500000	USD
CY2017Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	100900000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	181100000	USD
CY2018Q2	us-gaap	Other Than Temporary Impairment Losses Investments Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsAvailableforsaleSecurities	4400000	USD
	us-gaap	Other Than Temporary Impairment Losses Investments Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsAvailableforsaleSecurities	12300000	USD
CY2017Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	3343000000	USD
CY2018Q2	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	3302800000	USD
CY2017Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	925100000	USD
CY2018Q2	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	1074400000	USD
CY2017Q4	us-gaap	Other Long Term Investments OtherLongTermInvestments	3343800000	USD
CY2018Q2	us-gaap	Other Long Term Investments OtherLongTermInvestments	3495200000	USD
CY2017Q4	us-gaap	Other Policyholder Funds OtherPolicyholderFunds	2950300000	USD
CY2018Q2	us-gaap	Other Policyholder Funds OtherPolicyholderFunds	3009800000	USD
CY2017Q4	us-gaap	Other Receivables OtherReceivables	2266500000	USD
CY2018Q2	us-gaap	Other Receivables OtherReceivables	2182600000	USD
CY2017Q4	us-gaap	Other Short Term Investments OtherShortTermInvestments	17200000	USD
CY2018Q2	us-gaap	Other Short Term Investments OtherShortTermInvestments	23800000	USD
CY2017Q2	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Period Increase Decrease OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsPeriodIncreaseDecrease	-900000	USD
	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Period Increase Decrease OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsPeriodIncreaseDecrease	-4500000	USD
CY2018Q2	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Period Increase Decrease OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsPeriodIncreaseDecrease	0	USD
	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Period Increase Decrease OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsPeriodIncreaseDecrease	-200000	USD
CY2017Q2	us-gaap	Other Than Temporary Impairment Losses Investments Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsAvailableforsaleSecurities	7300000	USD
	us-gaap	Other Than Temporary Impairment Losses Investments Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsAvailableforsaleSecurities	16900000	USD
CY2017Q2	us-gaap	Other Than Temporary Impairment Losses Investments Portion In Other Comprehensive Income Loss Before Tax Including Portion Attributable To Noncontrolling Interest Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionInOtherComprehensiveIncomeLossBeforeTaxIncludingPortionAttributableToNoncontrollingInterestAvailableforsaleSecurities	-100000	USD
	us-gaap	Other Than Temporary Impairment Losses Investments Portion In Other Comprehensive Income Loss Before Tax Including Portion Attributable To Noncontrolling Interest Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionInOtherComprehensiveIncomeLossBeforeTaxIncludingPortionAttributableToNoncontrollingInterestAvailableforsaleSecurities	-1600000	USD
CY2018Q2	us-gaap	Other Than Temporary Impairment Losses Investments Portion In Other Comprehensive Income Loss Before Tax Including Portion Attributable To Noncontrolling Interest Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionInOtherComprehensiveIncomeLossBeforeTaxIncludingPortionAttributableToNoncontrollingInterestAvailableforsaleSecurities	0	USD
	us-gaap	Other Than Temporary Impairment Losses Investments Portion In Other Comprehensive Income Loss Before Tax Including Portion Attributable To Noncontrolling Interest Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionInOtherComprehensiveIncomeLossBeforeTaxIncludingPortionAttributableToNoncontrollingInterestAvailableforsaleSecurities	0	USD
CY2017Q2	us-gaap	Other Than Temporary Impairment Losses Investments Portion In Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionInOtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAvailableforsaleSecurities	-900000	USD
	us-gaap	Other Than Temporary Impairment Losses Investments Portion In Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionInOtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAvailableforsaleSecurities	-4500000	USD
CY2018Q2	us-gaap	Other Than Temporary Impairment Losses Investments Portion In Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionInOtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAvailableforsaleSecurities	0	USD
	us-gaap	Other Than Temporary Impairment Losses Investments Portion In Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionInOtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAvailableforsaleSecurities	-200000	USD
CY2017Q2	us-gaap	Other Than Temporary Impairment Losses Investments Portion In Other Comprehensive Income Loss Tax Including Portion Attributable To Noncontrolling Interest Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionInOtherComprehensiveIncomeLossTaxIncludingPortionAttributableToNoncontrollingInterestAvailableforsaleSecurities	-400000	USD
	us-gaap	Other Than Temporary Impairment Losses Investments Portion In Other Comprehensive Income Loss Tax Including Portion Attributable To Noncontrolling Interest Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionInOtherComprehensiveIncomeLossTaxIncludingPortionAttributableToNoncontrollingInterestAvailableforsaleSecurities	-2500000	USD
CY2018Q2	us-gaap	Other Than Temporary Impairment Losses Investments Portion In Other Comprehensive Income Loss Tax Including Portion Attributable To Noncontrolling Interest Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionInOtherComprehensiveIncomeLossTaxIncludingPortionAttributableToNoncontrollingInterestAvailableforsaleSecurities	0	USD
	us-gaap	Other Than Temporary Impairment Losses Investments Portion In Other Comprehensive Income Loss Tax Including Portion Attributable To Noncontrolling Interest Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionInOtherComprehensiveIncomeLossTaxIncludingPortionAttributableToNoncontrollingInterestAvailableforsaleSecurities	-100000	USD
CY2017Q2	us-gaap	Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet	7200000	USD
	us-gaap	Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet	15300000	USD
CY2018Q2	us-gaap	Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet	4400000	USD
	us-gaap	Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet	12300000	USD
CY2017Q4	us-gaap	Payables To Broker Dealers And Clearing Organizations PayablesToBrokerDealersAndClearingOrganizations	112600000	USD
CY2018Q2	us-gaap	Payables To Broker Dealers And Clearing Organizations PayablesToBrokerDealersAndClearingOrganizations	159900000	USD
	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	34611300000	USD
	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	34504600000	USD
	us-gaap	Payments For Proceeds From Derivative Instrument Investing Activities PaymentsForProceedsFromDerivativeInstrumentInvestingActivities	2100000	USD
	us-gaap	Payments For Proceeds From Derivative Instrument Investing Activities PaymentsForProceedsFromDerivativeInstrumentInvestingActivities	0	USD
	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-11800000	USD
	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-15200000	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	509000000	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	795000000	USD
CY2017Q1	us-gaap	Payments Of Dividends PaymentsOfDividends	172200000	USD
CY2017Q2	us-gaap	Payments Of Dividends PaymentsOfDividends	171800000	USD
	us-gaap	Payments Of Dividends PaymentsOfDividends	344000000	USD
CY2018Q1	us-gaap	Payments Of Dividends PaymentsOfDividends	191900000	USD
CY2018Q2	us-gaap	Payments Of Dividends PaymentsOfDividends	196400000	USD
	us-gaap	Payments Of Dividends PaymentsOfDividends	388300000	USD
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	45600000	USD

CY2018Q2

antm

Available For Sale Securities Debt Maturities Amortized Cost Noncurrent

AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostNoncurrent

489700000

USD

CY2017Q2

antm

Available For Sale Securities Other Than Temporary Impairments In Accumulated Other Comprehensive Income Deferred Tax Liability Asset

AvailableForSaleSecuritiesOtherThanTemporaryImpairmentsInAccumulatedOtherComprehensiveIncomeDeferredTaxLiabilityAsset

100000

USD

CY2018Q2

antm

Available For Sale Securities Other Than Temporary Impairments In Accumulated Other Comprehensive Income Deferred Tax Liability Asset

AvailableForSaleSecuritiesOtherThanTemporaryImpairmentsInAccumulatedOtherComprehensiveIncomeDeferredTaxLiabilityAsset

0

USD

CY2017Q2

antm

Cash Flow Hedging Instruments Accumulated Other Comprehensive Income Net Deferred Tax Asset

CashFlowHedgingInstrumentsAccumulatedOtherComprehensiveIncomeNetDeferredTaxAsset

124600000

USD

CY2018Q2

antm

Cash Flow Hedging Instruments Accumulated Other Comprehensive Income Net Deferred Tax Asset

CashFlowHedgingInstrumentsAccumulatedOtherComprehensiveIncomeNetDeferredTaxAsset

66900000

USD

CY2017Q2

antm

Deferred Net Actuarial Gain Loss Postretirement Benefits

DeferredNetActuarialGainLossPostretirementBenefits

-140900000

USD

CY2018Q2

antm

Deferred Net Actuarial Gain Loss Postretirement Benefits

DeferredNetActuarialGainLossPostretirementBenefits

-75700000

USD

CY2017Q2

antm

Accumulated Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Before Tax

AccumulatedOtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax

-3100000

USD

CY2018Q2

antm

Accumulated Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Before Tax

AccumulatedOtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax

-2100000

USD

CY2017Q2

antm

Available For Sale Securities Accumulated Other Comprehensive Income Net Deferred Tax Liability

AvailableForSaleSecuritiesAccumulatedOtherComprehensiveIncomeNetDeferredTaxLiability

-304000000

USD

CY2018Q2

antm

Available For Sale Securities Accumulated Other Comprehensive Income Net Deferred Tax Liability

AvailableForSaleSecuritiesAccumulatedOtherComprehensiveIncomeNetDeferredTaxLiability

15400000

USD

CY2017Q4

antm

Available For Sale Securities Debt Maturities Amortized Cost Noncurrent

AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostNoncurrent

556000000

USD

CY2017Q2

antm

Deferred Prior Service Cost Credit Postretirement Benefit Plans

DeferredPriorServiceCostCreditPostretirementBenefitPlans

52900000

USD

CY2018Q2

antm

Deferred Prior Service Cost Credit Postretirement Benefit Plans

DeferredPriorServiceCostCreditPostretirementBenefitPlans

39800000

USD

CY2017Q2

antm

Defined Benefit Plan Accumulated Other Comprehensive Income Adjustments Net Of Tax

DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeAdjustmentsNetOfTax

-390300000

USD

CY2018Q2

antm

Defined Benefit Plan Accumulated Other Comprehensive Income Adjustments Net Of Tax

DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeAdjustmentsNetOfTax

-445000000

USD

CY2017Q2

antm

Defined Benefit Plan Accumulated Other Comprehensive Income Net Deferred Tax Asset

DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetDeferredTaxAsset

-251600000

USD

CY2018Q2

antm

Defined Benefit Plan Accumulated Other Comprehensive Income Net Deferred Tax Asset

DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetDeferredTaxAsset

-155500000

USD

CY2017Q4

antm

Equity Securities

EquitySecurities

3632000000

USD

CY2018Q2

antm

Equity Securities

EquitySecurities

2468200000

USD

CY2017Q4

antm

Equity Securities Current

EquitySecuritiesCurrent

3599200000

USD

CY2018Q2

antm

Equity Securities Current

EquitySecuritiesCurrent

2435300000

USD

CY2017Q4

antm

Equitysecurities Longterm

EquitysecuritiesLongterm

32800000

USD

CY2018Q2

antm

Equitysecurities Longterm

EquitysecuritiesLongterm

32900000

USD

CY2018Q2

antm

Gross Premium Tax Rate

GrossPremiumTaxRate

0.0235

CY2017Q4

antm

Liability For Future Policy Benefits Current

LiabilityForFuturePolicyBenefitsCurrent

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Document Period End Date

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CY2018Q2

antm

Liability For Future Policy Benefits Current

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CY2018Q2

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Liability For Unpaid Claims And Claims Adjustment Expense Purchase Adjustments

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Document Type

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CY2017Q4

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Increase In Stock Repurchase Program Authorization

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CY2018Q2

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Merger Agreement Termination Fee

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Net Adjustment To Additional Paid In Capital For Equity Hedge

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CY2017Q2

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Netrealizedgainslossesonfinancialinstruments

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CY2018Q2

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Netrealizedgainslossesonfinancialinstruments

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antm

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CY2018Q2

antm

Number Of Counties In State Of Kansas Company Does Not Serve

NumberOfCountiesInStateOfKansasCompanyDoesNotServe

30

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CY2018Q2

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Number Of Medical Members

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CY2018Q2

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Numberofstatesinwhichcustomersareservedthroughsubsidiaries

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CY2017Q2

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Other Net Change In Unrecognized Periodic Benefit Costs For Defined Benefit Pension And Postretirement Benefit Plans Tax Benefit Expense

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antm

Other Net Change In Unrecognized Periodic Benefit Costs For Defined Benefit Pension And Postretirement Benefit Plans Tax Benefit Expense

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-2700000

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Other Net Change In Unrecognized Periodic Benefit Costs For Defined Benefit Pension And Postretirement Benefit Plans Tax Benefit Expense

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-5300000

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Payments For Proceeds From Financing Derivatives

PaymentsForProceedsFromFinancingDerivatives

128400000

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Payments For Proceeds From Financing Derivatives

PaymentsForProceedsFromFinancingDerivatives

-21900000

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Paymentstoacquireequitysecurities

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Percentageofrevenuessubjecttonewrevenueguidanceunder Asc606

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Potentially Dilutive Restricted Stock Units Contingent On Operating Results

PotentiallyDilutiveRestrictedStockUnitsContingentOnOperatingResults

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Potentially Dilutive Restricted Stock Units Contingent On Operating Results

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Proceedsfromsaleofequitysecurities

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Securities Lending Transactions Initial Collateral Percentage Value

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Securities Lending Transactions Ratioof Fair Valueof Collateral Held To Securities On Loan

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Securities Lending Transactions Ratioof Fair Valueof Collateral Held To Securities On Loan

SecuritiesLendingTransactionsRatioofFairValueofCollateralHeldToSecuritiesOnLoan

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SelfFundedReceivablesNet

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Self Funded Receivables Net

SelfFundedReceivablesNet

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Selffunded Receivables Allowance For Doubtful Accounts

SelffundedReceivablesAllowanceForDoubtfulAccounts

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Selffunded Receivables Allowance For Doubtful Accounts

SelffundedReceivablesAllowanceForDoubtfulAccounts

52300000

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Stock Repurchased And Retired During Period Average Price

StockRepurchasedAndRetiredDuringPeriodAveragePrice

180.37

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Stock Repurchased And Retired During Period Average Price

StockRepurchasedAndRetiredDuringPeriodAveragePrice

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Amendment Flag

AmendmentFlag

false

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Current Fiscal Year End Date

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Document Fiscal Period Focus

DocumentFiscalPeriodFocus

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Document Fiscal Year Focus

DocumentFiscalYearFocus

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Entity Central Index Key

EntityCentralIndexKey

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CY2018Q2

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Entity Common Stock Shares Outstanding

EntityCommonStockSharesOutstanding

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CY2018Q3

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Entity Common Stock Shares Outstanding

EntityCommonStockSharesOutstanding

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dei

Entity Filer Category

EntityFilerCategory

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Entity Registrant Name

EntityRegistrantName

Anthem, Inc.

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Trading Symbol

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ANTM

CY2017Q4

invest

Derivative Notional Amount

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CY2018Q2

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Derivative Notional Amount

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CY2017Q4

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CY2018Q2

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CY2017Q2

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Adjustment For Amortization

AdjustmentForAmortization

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Adjustments To Additional Paid In Capital Equity Component Of Convertible Debt Subsequent Adjustments

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Adjustments To Additional Paid In Capital Equity Component Of Convertible Debt Subsequent Adjustments

AdjustmentsToAdditionalPaidInCapitalEquityComponentOfConvertibleDebtSubsequentAdjustments

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AmortizationOfIntangibleAssets

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Amortization Of Intangible Assets

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us-gaap

Amortization Of Intangible Assets

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Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount

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Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount

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Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount

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Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount

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AssetsFairValueDisclosureRecurring

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Available For Sale Debt Securities Amortized Cost Basis

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Available For Sale Securities Accumulated Gross Unrealized Loss Before Tax

AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax

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CY2018Q2

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Available For Sale Securities Accumulated Gross Unrealized Loss Before Tax

AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax

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CY2017Q4

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Available For Sale Securities Debt Securities Current

AvailableForSaleSecuritiesDebtSecuritiesCurrent

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Available For Sale Securities Debt Securities Current

AvailableForSaleSecuritiesDebtSecuritiesCurrent

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Available For Sale Securities Debt Securities Noncurrent

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CY2017Q2

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Available For Sale Securities Gross Realized Gains

AvailableForSaleSecuritiesGrossRealizedGains

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Available For Sale Securities Gross Realized Gains

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Available For Sale Securities Gross Realized Gains

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Available For Sale Securities Gross Realized Losses

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AvailableForSaleSecuritiesGrossRealizedLosses

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Available For Sale Securities Gross Realized Losses

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Available For Sale Securities Income Tax Expense On Change In Unrealized Holding Gain Or Loss

AvailableForSaleSecuritiesIncomeTaxExpenseOnChangeInUnrealizedHoldingGainOrLoss

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Available For Sale Securities Income Tax Expense On Change In Unrealized Holding Gain Or Loss

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Available For Sale Securities Income Tax Expense On Change In Unrealized Holding Gain Or Loss

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us-gaap

Available For Sale Securities Income Tax Expense On Change In Unrealized Holding Gain Or Loss

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Benefits Losses And Expenses

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Benefits Losses And Expenses

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Cash And Cash Equivalents At Carrying Value

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Cash And Cash Equivalents Fair Value Disclosure

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Cash And Cash Equivalents Fair Value Disclosure

CashAndCashEquivalentsFairValueDisclosure

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Cash And Cash Equivalents Period Increase Decrease

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Cash And Cash Equivalents Period Increase Decrease

CashAndCashEquivalentsPeriodIncreaseDecrease

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Ceded Premiums Payable

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Comprehensive Income Net Of Tax

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Comprehensive Income Net Of Tax

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Defined Benefit Plan Accumulated Other Comprehensive Income Net Prior Service Cost Credit Before Tax

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Deposits Received For Securities Loaned At Carrying Value

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Derivative Asset Fair Value Gross Liability

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CY2018Q2

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Derivative Gain Loss On Derivative Net

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USD

us-gaap

Derivative Gain Loss On Derivative Net

DerivativeGainLossOnDerivativeNet

19300000

USD

CY2017Q4

us-gaap

Derivative Liability Collateral Right To Reclaim Cash Offset

DerivativeLiabilityCollateralRightToReclaimCashOffset

11500000

USD

CY2018Q2

us-gaap

Derivative Liability Collateral Right To Reclaim Cash Offset

DerivativeLiabilityCollateralRightToReclaimCashOffset

9000000

USD

CY2017Q1

us-gaap

Dividend Payable Date To Be Paid Day Month And Year

DividendPayableDateToBePaidDayMonthAndYear

2017-03-24

CY2017Q2

us-gaap

Dividend Payable Date To Be Paid Day Month And Year

DividendPayableDateToBePaidDayMonthAndYear

2017-06-23

CY2018Q1

us-gaap

Dividend Payable Date To Be Paid Day Month And Year

DividendPayableDateToBePaidDayMonthAndYear

2018-03-23

CY2018Q2

us-gaap

Dividend Payable Date To Be Paid Day Month And Year

DividendPayableDateToBePaidDayMonthAndYear

2018-06-25

us-gaap

Dividends Common Stock

DividendsCommonStock

344800000

USD

us-gaap

Dividends Common Stock

DividendsCommonStock

396100000

USD

CY2017Q1

us-gaap

Dividends Payable Date Declared Day Month And Year

DividendsPayableDateDeclaredDayMonthAndYear

2017-02-22

CY2017Q2

us-gaap

Dividends Payable Date Declared Day Month And Year

DividendsPayableDateDeclaredDayMonthAndYear

2017-04-27

CY2018Q1

us-gaap

Dividends Payable Date Declared Day Month And Year

DividendsPayableDateDeclaredDayMonthAndYear

2018-01-30

CY2018Q2

us-gaap

Dividends Payable Date Declared Day Month And Year

DividendsPayableDateDeclaredDayMonthAndYear

2018-04-24

CY2017Q1

us-gaap

Dividends Payable Date Of Record Day Month And Year

DividendsPayableDateOfRecordDayMonthAndYear

2017-03-10

CY2017Q2

us-gaap

Dividends Payable Date Of Record Day Month And Year

DividendsPayableDateOfRecordDayMonthAndYear

2017-06-09

CY2018Q1

us-gaap

Dividends Payable Date Of Record Day Month And Year

DividendsPayableDateOfRecordDayMonthAndYear

2018-03-09

CY2018Q2

us-gaap

Dividends Payable Date Of Record Day Month And Year

DividendsPayableDateOfRecordDayMonthAndYear

2018-06-08

CY2017Q2

us-gaap

Earnings Per Share Basic

EarningsPerShareBasic

3.23

us-gaap

Earnings Per Share Basic

EarningsPerShareBasic

7.05

CY2018Q2

us-gaap

Earnings Per Share Basic

EarningsPerShareBasic

4.07

us-gaap

Earnings Per Share Basic

EarningsPerShareBasic

9.20

CY2017Q2

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

3.16

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

6.89

CY2018Q2

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

3.98

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

8.97

us-gaap

Effect Of Exchange Rate On Cash And Cash Equivalents

EffectOfExchangeRateOnCashAndCashEquivalents

2900000

USD

us-gaap

Effect Of Exchange Rate On Cash And Cash Equivalents

EffectOfExchangeRateOnCashAndCashEquivalents

-400000

USD

CY2017Q2

us-gaap

Effective Income Tax Rate Continuing Operations

EffectiveIncomeTaxRateContinuingOperations

0.291

us-gaap

Effective Income Tax Rate Continuing Operations

EffectiveIncomeTaxRateContinuingOperations

0.314

CY2018Q2

us-gaap

Effective Income Tax Rate Continuing Operations

EffectiveIncomeTaxRateContinuingOperations

0.299

us-gaap

Effective Income Tax Rate Continuing Operations

EffectiveIncomeTaxRateContinuingOperations

0.280

CY2017Q2

us-gaap

Fair Value Assets Measured On Recurring Basis Change In Unrealized Gain Loss

FairValueAssetsMeasuredOnRecurringBasisChangeInUnrealizedGainLoss

-900000

USD

us-gaap

Fair Value Assets Measured On Recurring Basis Change In Unrealized Gain Loss

FairValueAssetsMeasuredOnRecurringBasisChangeInUnrealizedGainLoss

-2600000

USD

CY2018Q2

us-gaap

Fair Value Assets Measured On Recurring Basis Change In Unrealized Gain Loss

FairValueAssetsMeasuredOnRecurringBasisChangeInUnrealizedGainLoss

7400000

USD

us-gaap

Fair Value Assets Measured On Recurring Basis Change In Unrealized Gain Loss

FairValueAssetsMeasuredOnRecurringBasisChangeInUnrealizedGainLoss

37600000

USD

CY2017Q2

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1

400000

USD

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1

-600000

USD

CY2018Q2

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1

8100000

USD

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1

-230900000

USD

CY2017Q2

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss

600000

USD

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss

3900000

USD

CY2018Q2

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss

-2800000

USD

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss

-2400000

USD

CY2017Q2

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases

68000000

USD

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases

149800000

USD

CY2018Q2

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases

53400000

USD

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases

329000000

USD

CY2017Q2

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales

12000000

USD

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales

46500000

USD

CY2018Q2

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales

11600000

USD

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales

16100000

USD

CY2017Q2

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Settlements

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements

16800000

USD

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Settlements

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements

37000000

USD

CY2018Q2

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Settlements

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements

24000000

USD

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Settlements

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements

31100000

USD

CY2017Q2

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3

6300000

USD

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3

15800000

USD

CY2018Q2

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3

41800000

USD

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3

62600000

USD

CY2017Q2

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3

15200000

USD

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3

46400000

USD

CY2018Q2

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3

600000

USD

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3

FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3

2000000

USD

CY2016Q4

us-gaap

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value