$elv 2017 Q4 10-Q

Concept	2017 Q4	2017 Q3	2016 Q3
Revenue	$22.68B	$22.43B	$21.40B
YoY Change	4.46%	4.78%	7.55%
Cost Of Revenue		$18.10B	$16.92B
YoY Change		6.98%	9.4%
Gross Profit		$4.322B	$4.481B
YoY Change		-3.56%	1.1%
Gross Profit Margin		19.27%	20.94%
Selling, General & Admin	$3.393B	$3.011B	$3.125B
YoY Change	3.95%	-3.64%	1.43%
% of Gross Profit		69.67%	69.72%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$227.0M	$223.0M	$228.0M
YoY Change	-2.58%	-2.19%	-886.21%
% of Gross Profit		5.16%	5.09%
Operating Expenses	$22.11B	$3.011B	$3.125B
YoY Change	5.9%	-3.64%	1.43%
Operating Profit		$982.0M	$1.078B
YoY Change		-8.91%	-11.77%
Interest Expense	-$164.0M	$150.0M	$172.9M
YoY Change	-7.34%	-13.24%	4.92%
% of Operating Profit		15.27%	16.04%
Other Income/Expense, Net
YoY Change
Pretax Income	$126.0M	$1.119B	$1.137B
YoY Change	-80.87%	-1.54%	0.61%
Income Tax	$2.000M	$372.0M	$518.7M
% Of Pretax Income	1.59%	33.24%	45.64%
Net Earnings	$1.232B	$747.0M	$617.8M
YoY Change	234.42%	20.91%	-5.65%
Net Earnings / Revenue	5.43%	3.33%	2.89%
Basic Earnings Per Share	$4.80	$2.87	$2.35
Diluted Earnings Per Share	$4.67	$2.80	$2.30
COMMON SHARES
Basic Shares Outstanding	256.8M shares	260.5M shares	263.2M shares
Diluted Shares Outstanding		267.0M shares	268.1M shares

Concept	2017 Q4	2017 Q3	2016 Q3
SHORT-TERM ASSETS
Cash & Short-Term Investments	$20.99B	$24.79B	$20.76B
YoY Change	-1.19%	19.41%	6.78%
Cash & Equivalents	$3.609B	$6.097B	$2.546B
Short-Term Investments	$17.38B	$18.70B	$18.22B
Other Short-Term Assets	$2.249B	$1.822B	$1.907B
YoY Change	26.22%	-4.45%	1.53%
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets	$36.26B	$36.97B	$32.92B
YoY Change	5.68%	12.3%	4.39%
LONG-TERM ASSETS
Property, Plant & Equipment	$2.175B	$2.049B	$2.007B
YoY Change	9.97%	2.12%	3.93%
Goodwill	$19.23B	$17.59B	$17.56B
YoY Change	9.51%	0.15%	0.07%
Intangibles	$8.368B	$7.841B	$8.012B
YoY Change	5.06%	-2.14%	-2.47%
Long-Term Investments	$24.93B	$23.18B	$22.44B
YoY Change	16.26%	3.28%	2.61%
Other Assets	$565.0M	$850.9M	$1.169B
YoY Change	20.75%	-27.18%	76.7%
Total Long-Term Assets	$34.28B	$31.34B	$31.48B
YoY Change	11.4%	-0.44%	2.21%
TOTAL ASSETS
Total Short-Term Assets	$36.26B	$36.97B	$32.92B
Total Long-Term Assets	$34.28B	$31.34B	$31.48B
Total Assets	$70.54B	$68.31B	$64.40B
YoY Change	8.38%	6.07%	3.31%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$5.024B	$4.454B	$3.717B
YoY Change	25.13%	19.83%	12.88%
Accrued Expenses
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$1.275B	$1.180B	$440.0M
YoY Change	189.77%	168.18%	-18.52%
Long-Term Debt Due	$1.275B	$1.273B	$927.9M
YoY Change	37.33%	37.23%
Total Short-Term Liabilities	$23.36B	$24.41B	$21.04B
YoY Change	9.68%	16.05%	14.54%
LONG-TERM LIABILITIES
Long-Term Debt	$17.38B	$13.78B	$14.24B
YoY Change	21.06%	-3.26%	-9.4%
Other Long-Term Liabilities	$925.0M	$944.0M	$1.041B
YoY Change	4.66%	-9.29%	-15.3%
Total Long-Term Liabilities	$18.31B	$14.72B	$15.28B
YoY Change	20.11%	-3.68%	-9.83%
TOTAL LIABILITIES
Total Short-Term Liabilities	$23.36B	$24.41B	$21.04B
Total Long-Term Liabilities	$18.31B	$14.72B	$15.28B
Total Liabilities	$44.04B	$42.36B	$39.66B
YoY Change	10.14%	6.82%	1.42%
SHAREHOLDERS EQUITY
Retained Earnings	$18.05B	$17.31B	$16.36B
YoY Change	9.02%	5.76%	10.85%
Common Stock	$3.000M	$2.600M	$2.600M
YoY Change	15.38%	0.0%	0.0%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$26.50B	$25.95B	$24.74B
YoY Change
Total Liabilities & Shareholders Equity	$70.54B	$68.31B	$64.40B
YoY Change	8.38%	6.07%	3.31%

Concept	2017 Q4	2017 Q3	2016 Q3
OPERATING ACTIVITIES
Net Income	$1.232B	$747.0M	$617.8M
YoY Change	234.42%	20.91%	-5.65%
Depreciation, Depletion And Amortization	$227.0M	$223.0M	$228.0M
YoY Change	-2.58%	-2.19%	-886.21%
Cash From Operating Activities	-$1.301B	$2.405B	$964.0M
YoY Change	-713.68%	149.48%	181.05%
INVESTING ACTIVITIES
Capital Expenditures	-$284.0M	-$218.0M	-$165.0M
YoY Change	69.05%	32.12%	-7.3%
Acquisitions
YoY Change
Other Investing Activities	-$3.337B	$1.025B	$688.0M
YoY Change	-497.74%	48.98%	62.65%
Cash From Investing Activities	-$3.620B	$807.0M	$523.0M
YoY Change	-639.49%	54.3%	113.47%
FINANCING ACTIVITIES
Cash Dividend Paid	$180.0M	$181.0M	$171.1M
YoY Change	5.08%	5.79%	4.97%
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	2.433B	-1.676B	-525.0M
YoY Change	277.21%	219.24%	-11.62%
NET CHANGE
Cash From Operating Activities	-1.301B	2.405B	964.0M
Cash From Investing Activities	-3.620B	807.0M	523.0M
Cash From Financing Activities	2.433B	-1.676B	-525.0M
Net Change In Cash	-2.488B	1.536B	962.0M
YoY Change	-262.83%	59.67%	-16133.33%
FREE CASH FLOW
Cash From Operating Activities	-$1.301B	$2.405B	$964.0M
Capital Expenditures	-$284.0M	-$218.0M	-$165.0M
Free Cash Flow	-$1.017B	$2.623B	$1.129B
YoY Change	-367.63%	132.33%	116.7%

Frame	Concept Type	Concept / XBRL Key	Value	Unit
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CY2017Q3	antm	Accumulated Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Before Tax AccumulatedOtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	-2400000	USD
CY2016Q3	antm	Available For Sale Securities Accumulated Other Comprehensive Income Net Deferred Tax Liability AvailableForSaleSecuritiesAccumulatedOtherComprehensiveIncomeNetDeferredTaxLiability	-364000000	USD
CY2017Q3	antm	Available For Sale Securities Accumulated Other Comprehensive Income Net Deferred Tax Liability AvailableForSaleSecuritiesAccumulatedOtherComprehensiveIncomeNetDeferredTaxLiability	-309900000	USD
CY2016Q4	antm	Available For Sale Securities Debt Maturities Amortized Cost Noncurrent AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostNoncurrent	524600000	USD
CY2017Q3	antm	Available For Sale Securities Debt Maturities Amortized Cost Noncurrent AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostNoncurrent	524700000	USD
CY2016Q4	antm	Available For Sale Securities Equity Securities Cost Current AvailableForSaleSecuritiesEquitySecuritiesCostCurrent	1076100000	USD
CY2017Q3	antm	Available For Sale Securities Equity Securities Cost Current AvailableForSaleSecuritiesEquitySecuritiesCostCurrent	1033700000	USD
CY2016Q4	antm	Available For Sale Securities Equity Securities Cost Noncurrent AvailableForSaleSecuritiesEquitySecuritiesCostNoncurrent	27200000	USD
	antm	Securities Lending Transactions Initial Collateral Percentage Value SecuritiesLendingTransactionsInitialCollateralPercentageValue	1.02
CY2016Q3	antm	Available For Sale Securities Other Than Temporary Impairments In Accumulated Other Comprehensive Income Deferred Tax Liability Asset AvailableForSaleSecuritiesOtherThanTemporaryImpairmentsInAccumulatedOtherComprehensiveIncomeDeferredTaxLiabilityAsset	4300000	USD
CY2017Q3	antm	Available For Sale Securities Other Than Temporary Impairments In Accumulated Other Comprehensive Income Deferred Tax Liability Asset AvailableForSaleSecuritiesOtherThanTemporaryImpairmentsInAccumulatedOtherComprehensiveIncomeDeferredTaxLiabilityAsset	100000	USD
CY2017Q3	antm	Available For Sale Securities Equity Securities Cost Noncurrent AvailableForSaleSecuritiesEquitySecuritiesCostNoncurrent	27300000	USD
CY2016Q3	antm	Cash Flow Hedging Instruments Accumulated Other Comprehensive Income Net Deferred Tax Asset CashFlowHedgingInstrumentsAccumulatedOtherComprehensiveIncomeNetDeferredTaxAsset	298200000	USD
CY2017Q3	antm	Cash Flow Hedging Instruments Accumulated Other Comprehensive Income Net Deferred Tax Asset CashFlowHedgingInstrumentsAccumulatedOtherComprehensiveIncomeNetDeferredTaxAsset	127100000	USD
CY2016Q3	antm	Deferred Net Actuarial Gain Loss Postretirement Benefits DeferredNetActuarialGainLossPostretirementBenefits	-153400000	USD
CY2017Q3	antm	Deferred Net Actuarial Gain Loss Postretirement Benefits DeferredNetActuarialGainLossPostretirementBenefits	-138000000	USD
CY2016Q3	antm	Deferred Prior Service Cost Credit Postretirement Benefit Plans DeferredPriorServiceCostCreditPostretirementBenefitPlans	63200000	USD
CY2017Q3	antm	Deferred Prior Service Cost Credit Postretirement Benefit Plans DeferredPriorServiceCostCreditPostretirementBenefitPlans	49500000	USD
CY2016Q3	antm	Defined Benefit Plan Accumulated Other Comprehensive Income Adjustments Net Of Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeAdjustmentsNetOfTax	-373100000	USD
CY2017Q3	antm	Defined Benefit Plan Accumulated Other Comprehensive Income Adjustments Net Of Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeAdjustmentsNetOfTax	-385300000	USD
CY2016Q3	antm	Defined Benefit Plan Accumulated Other Comprehensive Income Net Deferred Tax Asset DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetDeferredTaxAsset	-243000000	USD
CY2017Q3	antm	Defined Benefit Plan Accumulated Other Comprehensive Income Net Deferred Tax Asset DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetDeferredTaxAsset	-248400000	USD
CY2017Q3	antm	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Per Share Amount EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitPerShareAmount	0.01
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CY2017Q3	antm	Gross Premium Tax Rate GrossPremiumTaxRate	0.0235
CY2014Q4	antm	Increase In Stock Repurchase Program Authorization IncreaseInStockRepurchaseProgramAuthorization	5000000000	USD
CY2016Q4	antm	Liability For Future Policy Benefits Current LiabilityForFuturePolicyBenefitsCurrent	71800000	USD
CY2017Q3	antm	Liability For Future Policy Benefits Current LiabilityForFuturePolicyBenefitsCurrent	72100000	USD
CY2017Q3	antm	Merger Agreement Termination Fee MergerAgreementTerminationFee	1850000000	USD
	antm	Net Adjustment To Additional Paid In Capital For Equity Hedge NetAdjustmentToAdditionalPaidInCapitalForEquityHedge	900000	USD
CY2016Q3	antm	Netrealizedgainslossesonfinancialinstruments Netrealizedgainslossesonfinancialinstruments	88800000	USD
	antm	Netrealizedgainslossesonfinancialinstruments Netrealizedgainslossesonfinancialinstruments	-23800000	USD
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	antm	Netrealizedgainslossesonfinancialinstruments Netrealizedgainslossesonfinancialinstruments	138200000	USD
CY2017Q3	antm	Number Of Counties In Geographical Region Served As Independent Licensee NumberOfCountiesInGeographicalRegionServedAsIndependentLicensee	10	county
CY2017Q3	antm	Number Of Counties In State Of Kansas Company Does Not Serve NumberOfCountiesInStateOfKansasCompanyDoesNotServe	30	county
CY2017Q3	antm	Number Of Medical Members NumberOfMedicalMembers	40300000	medical_member
CY2016Q3	antm	Other Net Change In Unrecognized Periodic Benefit Costs For Defined Benefit Pension And Postretirement Benefit Plans Tax Benefit Expense OtherNetChangeInUnrecognizedPeriodicBenefitCostsForDefinedBenefitPensionAndPostretirementBenefitPlansTaxBenefitExpense	-1700000	USD
	antm	Other Net Change In Unrecognized Periodic Benefit Costs For Defined Benefit Pension And Postretirement Benefit Plans Tax Benefit Expense OtherNetChangeInUnrecognizedPeriodicBenefitCostsForDefinedBenefitPensionAndPostretirementBenefitPlansTaxBenefitExpense	-7000000	USD
CY2017Q3	antm	Other Net Change In Unrecognized Periodic Benefit Costs For Defined Benefit Pension And Postretirement Benefit Plans Tax Benefit Expense OtherNetChangeInUnrecognizedPeriodicBenefitCostsForDefinedBenefitPensionAndPostretirementBenefitPlansTaxBenefitExpense	-3000000	USD
	antm	Other Net Change In Unrecognized Periodic Benefit Costs For Defined Benefit Pension And Postretirement Benefit Plans Tax Benefit Expense OtherNetChangeInUnrecognizedPeriodicBenefitCostsForDefinedBenefitPensionAndPostretirementBenefitPlansTaxBenefitExpense	-8200000	USD
	antm	Payments For Proceeds From Financing Derivatives PaymentsForProceedsFromFinancingDerivatives	1034000000	USD
	antm	Payments For Proceeds From Financing Derivatives PaymentsForProceedsFromFinancingDerivatives	175600000	USD
	antm	Percentageofrevenuessubjecttonewrevenueguidanceunder Asc606 PercentageofrevenuessubjecttonewrevenueguidanceunderASC606	0.060
	antm	Potentially Dilutive Restricted Stock Units Contingent On Operating Results PotentiallyDilutiveRestrictedStockUnitsContingentOnOperatingResults	500000	shares
	antm	Potentially Dilutive Restricted Stock Units Contingent On Operating Results PotentiallyDilutiveRestrictedStockUnitsContingentOnOperatingResults	400000	shares
	antm	Present Value Of Contract Liability Debt Issuance Costs Related To Equity Units PresentValueOfContractLiabilityDebtIssuanceCostsRelatedToEquityUnits	300000	USD
CY2016	antm	Securities Lending Transactions Initial Collateral Percentage Value SecuritiesLendingTransactionsInitialCollateralPercentageValue	1.02
CY2016	antm	Securities Lending Transactions Ratioof Fair Valueof Collateral Held To Securities On Loan SecuritiesLendingTransactionsRatioofFairValueofCollateralHeldToSecuritiesOnLoan	1.03
	antm	Securities Lending Transactions Ratioof Fair Valueof Collateral Held To Securities On Loan SecuritiesLendingTransactionsRatioofFairValueofCollateralHeldToSecuritiesOnLoan	1.03
	antm	Stock Repurchased And Retired During Period Average Price StockRepurchasedAndRetiredDuringPeriodAveragePrice	186.80
	dei	Amendment Flag AmendmentFlag	false
	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	Q3
	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2017
	dei	Document Period End Date DocumentPeriodEndDate	2017-09-30
	dei	Document Type DocumentType	10-Q
	dei	Entity Central Index Key EntityCentralIndexKey	0001156039
CY2017Q3	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	257404755	shares
CY2017Q4	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	256760521	shares
	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
	dei	Entity Registrant Name EntityRegistrantName	Anthem, Inc.
	dei	Trading Symbol TradingSymbol	ANTM
CY2016Q4	invest	Derivative Notional Amount DerivativeNotionalAmount	16834900000	USD
CY2017Q3	invest	Derivative Notional Amount DerivativeNotionalAmount	6263100000	USD
CY2016Q4	us-gaap	Accounts Payable And Accrued Liabilities Current AccountsPayableAndAccruedLiabilitiesCurrent	4014900000	USD
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CY2016Q4	us-gaap	Accrued Income Taxes Current AccruedIncomeTaxesCurrent	0	USD
CY2017Q3	us-gaap	Accrued Income Taxes Current AccruedIncomeTaxesCurrent	187500000	USD
CY2016Q4	us-gaap	Accrued Investment Income Receivable AccruedInvestmentIncomeReceivable	164500000	USD
CY2017Q3	us-gaap	Accrued Investment Income Receivable AccruedInvestmentIncomeReceivable	158300000	USD
CY2016Q3	us-gaap	Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	630700000	USD
CY2017Q3	us-gaap	Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	550900000	USD
CY2016Q3	us-gaap	Accumulated Other Comprehensive Income Loss Cumulative Changes In Net Gain Loss From Cash Flow Hedges Effect Net Of Tax AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax	-553800000	USD
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CY2016Q3	us-gaap	Accumulated Other Comprehensive Income Loss Foreign Currency Translation Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax	-5200000	USD
CY2017Q3	us-gaap	Accumulated Other Comprehensive Income Loss Foreign Currency Translation Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax	-1500000	USD
CY2016Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-363900000	USD
CY2016Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-267900000	USD
CY2017Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-126000000	USD
CY2016Q3	us-gaap	Accumulated Other Comprehensive Income Loss Other Than Temporary Impairment Not Credit Loss Net Of Tax Availableforsale Debt Securities AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxAvailableforsaleDebtSecurities	12100000	USD
CY2017Q3	us-gaap	Accumulated Other Comprehensive Income Loss Other Than Temporary Impairment Not Credit Loss Net Of Tax Availableforsale Debt Securities AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxAvailableforsaleDebtSecurities	200000	USD
CY2016Q3	us-gaap	Accumulated Other Comprehensive Income Loss Other Than Temporary Impairment Not Credit Loss Net Of Tax Debt Securities AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities	7800000	USD
CY2017Q3	us-gaap	Accumulated Other Comprehensive Income Loss Other Than Temporary Impairment Not Credit Loss Net Of Tax Debt Securities AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities	100000	USD
CY2016Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	8805100000	USD
CY2017Q3	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	8765100000	USD
	us-gaap	Adjustment For Amortization AdjustmentForAmortization	601700000	USD
	us-gaap	Adjustment For Amortization AdjustmentForAmortization	581200000	USD
	us-gaap	Adjustments To Additional Paid In Capital Equity Component Of Convertible Debt Subsequent Adjustments AdjustmentsToAdditionalPaidInCapitalEquityComponentOfConvertibleDebtSubsequentAdjustments	-1100000	USD
CY2016Q3	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	47400000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	145700000	USD
CY2017Q3	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	41900000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	124300000	USD
CY2016Q3	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	2500000	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	2300000	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	500000	shares
CY2016Q4	us-gaap	Assets Assets	65083100000	USD
CY2017Q3	us-gaap	Assets Assets	68309900000	USD
CY2016Q4	us-gaap	Assets Current AssetsCurrent	34314900000	USD
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	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	9.70
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CY2016Q4	us-gaap	Assets Fair Value Disclosure Recurring AssetsFairValueDisclosureRecurring	22587700000	USD
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CY2016Q3	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	1068900000	USD
CY2017Q3	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	940900000	USD
CY2016Q3	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	74200000	USD
CY2017Q3	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	80100000	USD
CY2016Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	16991800000	USD
CY2017Q3	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	18269000000	USD
CY2016Q4	us-gaap	Available For Sale Securities AvailableForSaleSecurities	19187400000	USD
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CY2016Q3	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Gain Loss Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainLossBeforeTax	994700000	USD
CY2017Q3	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Gain Loss Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainLossBeforeTax	860800000	USD
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CY2016Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	42400000	USD
CY2017Q3	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	32700000	USD
CY2016Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	138500000	USD
CY2017Q3	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	47400000	USD
CY2016Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	6220300000	USD
CY2017Q3	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	3662900000	USD
CY2016Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	816000000	USD
CY2017Q3	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	1127900000	USD
CY2016Q4	us-gaap	Available For Sale Securities Debt Securities Current AvailableForSaleSecuritiesDebtSecuritiesCurrent	17163100000	USD
CY2017Q3	us-gaap	Available For Sale Securities Debt Securities Current AvailableForSaleSecuritiesDebtSecuritiesCurrent	18697300000	USD
CY2016Q4	us-gaap	Available For Sale Securities Debt Securities Noncurrent AvailableForSaleSecuritiesDebtSecuritiesNoncurrent	524400000	USD
CY2017Q3	us-gaap	Available For Sale Securities Debt Securities Noncurrent AvailableForSaleSecuritiesDebtSecuritiesNoncurrent	533300000	USD
CY2016Q4	us-gaap	Available For Sale Securities Equity Securities Current AvailableForSaleSecuritiesEquitySecuritiesCurrent	1468500000	USD
CY2017Q3	us-gaap	Available For Sale Securities Equity Securities Current AvailableForSaleSecuritiesEquitySecuritiesCurrent	1452600000	USD
CY2016Q4	us-gaap	Available For Sale Securities Equity Securities Noncurrent AvailableForSaleSecuritiesEquitySecuritiesNoncurrent	31400000	USD
CY2017Q3	us-gaap	Available For Sale Securities Equity Securities Noncurrent AvailableForSaleSecuritiesEquitySecuritiesNoncurrent	32300000	USD
CY2016Q3	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	113400000	USD
	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	343200000	USD
CY2017Q3	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	144400000	USD
	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	255100000	USD
CY2016Q3	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	13000000	USD
	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	136700000	USD
CY2017Q3	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	17200000	USD
	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	67500000	USD
CY2016Q4	us-gaap	Available For Sale Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions Less Than One Year AvailableForSaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsLessThanOneYear	3330	securities
CY2017Q3	us-gaap	Available For Sale Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions Less Than One Year AvailableForSaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsLessThanOneYear	1968	securities
CY2016Q3	us-gaap	Available For Sale Securities Income Tax Expense On Change In Unrealized Holding Gain Or Loss AvailableForSaleSecuritiesIncomeTaxExpenseOnChangeInUnrealizedHoldingGainOrLoss	-36700000	USD
	us-gaap	Available For Sale Securities Income Tax Expense On Change In Unrealized Holding Gain Or Loss AvailableForSaleSecuritiesIncomeTaxExpenseOnChangeInUnrealizedHoldingGainOrLoss	-275800000	USD
CY2017Q3	us-gaap	Available For Sale Securities Income Tax Expense On Change In Unrealized Holding Gain Or Loss AvailableForSaleSecuritiesIncomeTaxExpenseOnChangeInUnrealizedHoldingGainOrLoss	-48500000	USD
	us-gaap	Available For Sale Securities Income Tax Expense On Change In Unrealized Holding Gain Or Loss AvailableForSaleSecuritiesIncomeTaxExpenseOnChangeInUnrealizedHoldingGainOrLoss	-161200000	USD
CY2016Q4	us-gaap	Availableforsale Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions Greater Than Or Equal To One Year AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsGreaterThanOrEqualToOneYear	425	securities
CY2017Q3	us-gaap	Availableforsale Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions Greater Than Or Equal To One Year AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsGreaterThanOrEqualToOneYear	648	securities
CY2016Q3	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	20267400000	USD
	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	59251800000	USD
CY2017Q3	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	21307100000	USD
	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	63519500000	USD
CY2015Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	2113500000	USD
CY2016Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	2546000000	USD
CY2016Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	4075300000	USD
CY2017Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	6097200000	USD
CY2016Q4	us-gaap	Cash And Cash Equivalents Fair Value Disclosure CashAndCashEquivalentsFairValueDisclosure	1546000000	USD
CY2017Q3	us-gaap	Cash And Cash Equivalents Fair Value Disclosure CashAndCashEquivalentsFairValueDisclosure	4126400000	USD
	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	432500000	USD
	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	2021900000	USD
CY2015Q4	us-gaap	Ceded Premiums Payable CededPremiumsPayable	645600000	USD
CY2016Q3	us-gaap	Ceded Premiums Payable CededPremiumsPayable	397500000	USD
CY2016Q4	us-gaap	Ceded Premiums Payable CededPremiumsPayable	539100000	USD
CY2017Q3	us-gaap	Ceded Premiums Payable CededPremiumsPayable	101400000	USD
CY2016Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2017Q3	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2016Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.65
CY2016Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.65
CY2016Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.65
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
CY2017Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.70
CY2016Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.65
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.95
CY2017Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.70
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	2.00
CY2016Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2017Q3	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2016Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	900000000	shares
CY2017Q3	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	900000000	shares
CY2016Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	263747395	shares
CY2017Q3	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	257404755	shares
CY2016Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	263747395	shares
CY2017Q3	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	257404755	shares
CY2016Q4	us-gaap	Common Stock Value CommonStockValue	2600000	USD
CY2017Q3	us-gaap	Common Stock Value CommonStockValue	2600000	USD
CY2016Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	618800000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	2030100000	USD
CY2017Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	755800000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	2754000000	USD
	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	3900000	USD
	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	81600000	USD
	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-237500000	USD
CY2016Q3	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits	35500000	USD
CY2017Q3	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits	34600000	USD
CY2016Q3	us-gaap	Deferred Tax Assets Unrealized Currency Losses DeferredTaxAssetsUnrealizedCurrencyLosses	2700000	USD
CY2017Q3	us-gaap	Deferred Tax Assets Unrealized Currency Losses DeferredTaxAssetsUnrealizedCurrencyLosses	900000	USD
CY2016Q4	us-gaap	Deferred Tax Liabilities Noncurrent DeferredTaxLiabilitiesNoncurrent	2779900000	USD
CY2017Q3	us-gaap	Deferred Tax Liabilities Noncurrent DeferredTaxLiabilitiesNoncurrent	2609300000	USD
CY2016Q3	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Net Gains Losses Before Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax	-615800000	USD
CY2017Q3	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Net Gains Losses Before Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax	-632900000	USD
CY2016Q3	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Net Prior Service Cost Credit Before Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax	300000	USD
CY2017Q3	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Net Prior Service Cost Credit Before Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax	800000	USD
CY2016Q3	us-gaap	Defined Benefit Plan Contributions By Employer DefinedBenefitPlanContributionsByEmployer	300000	USD
	us-gaap	Defined Benefit Plan Contributions By Employer DefinedBenefitPlanContributionsByEmployer	300000	USD
CY2017Q3	us-gaap	Defined Benefit Plan Contributions By Employer DefinedBenefitPlanContributionsByEmployer	200000	USD
	us-gaap	Defined Benefit Plan Contributions By Employer DefinedBenefitPlanContributionsByEmployer	200000	USD
CY2016Q4	us-gaap	Deposits Received For Securities Loaned At Carrying Value DepositsReceivedForSecuritiesLoanedAtCarryingValue	1078900000	USD
CY2017Q3	us-gaap	Deposits Received For Securities Loaned At Carrying Value DepositsReceivedForSecuritiesLoanedAtCarryingValue	906400000	USD
	us-gaap	Depreciation Depreciation	77700000	USD
	us-gaap	Depreciation Depreciation	81700000	USD
CY2016Q4	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	92800000	USD
CY2017Q3	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	7200000	USD
CY2016Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	758700000	USD
CY2017Q3	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	7200000	USD
CY2016Q4	us-gaap	Derivative Fair Value Of Derivative Asset Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral	665900000	USD
CY2017Q3	us-gaap	Derivative Fair Value Of Derivative Asset Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral	0	USD
CY2016Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	241900000	USD
CY2017Q3	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	79900000	USD
CY2016Q4	us-gaap	Derivative Fair Value Of Derivative Liability Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral	149100000	USD
CY2017Q3	us-gaap	Derivative Fair Value Of Derivative Liability Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral	0	USD
CY2016Q3	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	-3900000	USD
	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	-222600000	USD
CY2017Q3	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	-12500000	USD
	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	-37400000	USD
CY2016Q4	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	92800000	USD
CY2017Q3	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	79900000	USD
CY2016Q1	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2016-03-25
CY2016Q2	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2016-06-24
CY2016Q3	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2016-09-26
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
CY2017Q3	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2017-09-25
	us-gaap	Dividends Common Stock DividendsCommonStock	515800000	USD
	us-gaap	Dividends Common Stock DividendsCommonStock	526800000	USD
CY2016Q1	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2016-02-18
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	7.84
CY2017Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.80
CY2016Q3	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2016-09-09
CY2016Q2	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2016-04-26
CY2016Q3	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2016-07-26
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
CY2017Q3	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2017-07-25
CY2016Q1	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2016-03-10
CY2016Q2	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2016-06-10
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
CY2017Q3	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2017-09-08
CY2016Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.35
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	8.00
CY2017Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.87
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	9.92
CY2016Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.30
CY2016Q3	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.456
	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.461
CY2017Q3	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.332
	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.320
CY2016Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales	11400000	USD
	us-gaap	Excess Tax Benefit From Share Based Compensation Financing Activities ExcessTaxBenefitFromShareBasedCompensationFinancingActivities	48700000	USD
	us-gaap	Excess Tax Benefit From Share Based Compensation Financing Activities ExcessTaxBenefitFromShareBasedCompensationFinancingActivities	0	USD
	us-gaap	Excess Tax Benefit From Share Based Compensation Operating Activities ExcessTaxBenefitFromShareBasedCompensationOperatingActivities	48700000	USD
	us-gaap	Excess Tax Benefit From Share Based Compensation Operating Activities ExcessTaxBenefitFromShareBasedCompensationOperatingActivities	0	USD
CY2016Q3	us-gaap	Fair Value Assets Measured On Recurring Basis Change In Unrealized Gain Loss FairValueAssetsMeasuredOnRecurringBasisChangeInUnrealizedGainLoss	-100000	USD
	us-gaap	Fair Value Assets Measured On Recurring Basis Change In Unrealized Gain Loss FairValueAssetsMeasuredOnRecurringBasisChangeInUnrealizedGainLoss	-1900000	USD
CY2017Q3	us-gaap	Fair Value Assets Measured On Recurring Basis Change In Unrealized Gain Loss FairValueAssetsMeasuredOnRecurringBasisChangeInUnrealizedGainLoss	-600000	USD
	us-gaap	Fair Value Assets Measured On Recurring Basis Change In Unrealized Gain Loss FairValueAssetsMeasuredOnRecurringBasisChangeInUnrealizedGainLoss	-3200000	USD
CY2016Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	-500000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	100000	USD
CY2017Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	-500000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	-1100000	USD
CY2016Q3	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	-2600000	USD
CY2017Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	4800000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	8700000	USD
CY2016Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases	69700000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases	233900000	USD
CY2017Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases	47900000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases	197700000	USD
CY2017Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	520400000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales	23700000	USD
CY2017Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales	3300000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales	49800000	USD
CY2016Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements	6600000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements	27800000	USD
CY2017Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements	18600000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements	55600000	USD
CY2016Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	13800000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	35500000	USD
CY2017Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	4100000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	19900000	USD
CY2016Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	0	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	59100000	USD
CY2017Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	27800000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	74200000	USD
CY2015Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	315800000	USD
CY2016Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	407700000	USD
CY2016Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	472100000	USD
CY2016Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	481400000	USD
CY2017Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	527000000	USD
	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-3500000	USD
	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-3500000	USD
CY2016Q3	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	2786100000	USD
	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	8254000000	USD
CY2017Q3	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	2663200000	USD
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CY2016Q4	us-gaap	Good Faith And Margin Deposits With Broker Dealers GoodFaithAndMarginDepositsWithBrokerDealers	405300000	USD
CY2017Q3	us-gaap	Good Faith And Margin Deposits With Broker Dealers GoodFaithAndMarginDepositsWithBrokerDealers	201400000	USD
CY2016Q4	us-gaap	Goodwill Goodwill	17561200000	USD
CY2017Q3	us-gaap	Goodwill Goodwill	17587800000	USD
CY2016Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	1136500000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	3896800000	USD
CY2017Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	1118900000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	3839600000	USD
CY2016Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	1136500000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	3896800000	USD
CY2017Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	1118900000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	3839600000	USD
CY2016Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	518700000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	1795400000	USD
CY2017Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	372000000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	1227500000	USD
CY2016Q3	us-gaap	Income Tax Reconciliation Nondeductible Expense IncomeTaxReconciliationNondeductibleExpense	100500000	USD
	us-gaap	Income Tax Reconciliation Nondeductible Expense IncomeTaxReconciliationNondeductibleExpense	308800000	USD
CY2017Q3	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	2100000	USD
	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	27300000	USD
CY2016Q4	us-gaap	Income Taxes Receivable IncomeTaxesReceivable	168700000	USD
CY2017Q3	us-gaap	Income Taxes Receivable IncomeTaxesReceivable	0	USD
	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	86900000	USD
	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	563700000	USD
	us-gaap	Increase Decrease In Collateral Held Under Securities Lending IncreaseDecreaseInCollateralHeldUnderSecuritiesLending	58400000	USD
	us-gaap	Increase Decrease In Collateral Held Under Securities Lending IncreaseDecreaseInCollateralHeldUnderSecuritiesLending	-172500000	USD
	us-gaap	Increase Decrease In Income Taxes Payable Net Of Income Taxes Receivable IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable	410600000	USD
	us-gaap	Increase Decrease In Income Taxes Payable Net Of Income Taxes Receivable IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable	356200000	USD
	us-gaap	Increase Decrease In Insurance Liabilities IncreaseDecreaseInInsuranceLiabilities	-249500000	USD
	us-gaap	Increase Decrease In Insurance Liabilities IncreaseDecreaseInInsuranceLiabilities	274600000	USD
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	925200000	USD
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	517000000	USD
	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	53900000	USD
	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	52100000	USD
	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	381600000	USD
	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	251000000	USD
	us-gaap	Increase Decrease In Outstanding Checks Financing Activities IncreaseDecreaseInOutstandingChecksFinancingActivities	311500000	USD
	us-gaap	Increase Decrease In Outstanding Checks Financing Activities IncreaseDecreaseInOutstandingChecksFinancingActivities	-126500000	USD
	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	176200000	USD
	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	-611600000	USD
	us-gaap	Increase Decrease In Securities Lending Payable IncreaseDecreaseInSecuritiesLendingPayable	58400000	USD
	us-gaap	Increase Decrease In Securities Lending Payable IncreaseDecreaseInSecuritiesLendingPayable	-172500000	USD
	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	17700000	USD
	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	26200000	USD
	us-gaap	Increase Decrease In Unearned Premiums IncreaseDecreaseInUnearnedPremiums	467900000	USD
	us-gaap	Increase Decrease In Unearned Premiums IncreaseDecreaseInUnearnedPremiums	969800000	USD
CY2016Q3	us-gaap	Insurance Services Revenue InsuranceServicesRevenue	21125200000	USD
	us-gaap	Insurance Services Revenue InsuranceServicesRevenue	62709100000	USD
CY2017Q3	us-gaap	Insurance Services Revenue InsuranceServicesRevenue	22096700000	USD
	us-gaap	Insurance Services Revenue InsuranceServicesRevenue	66614200000	USD
CY2016Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	7964900000	USD
CY2017Q3	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	7840600000	USD
CY2016Q3	us-gaap	Interest Expense InterestExpense	172900000	USD
	us-gaap	Interest Expense InterestExpense	545700000	USD
CY2017Q3	us-gaap	Interest Expense InterestExpense	150500000	USD
	us-gaap	Interest Expense InterestExpense	575400000	USD
CY2016Q4	us-gaap	Liabilities Liabilities	39982700000	USD
CY2017Q3	us-gaap	Liabilities Liabilities	42361600000	USD
CY2016Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	65083100000	USD
CY2017Q3	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	68309900000	USD
CY2016Q4	us-gaap	Liabilities Current LiabilitiesCurrent	21294400000	USD
CY2017Q3	us-gaap	Liabilities Current LiabilitiesCurrent	24412500000	USD
CY2016Q4	us-gaap	Liabilities Fair Value Disclosure Recurring LiabilitiesFairValueDisclosureRecurring	241900000	USD
CY2017Q3	us-gaap	Liabilities Fair Value Disclosure Recurring LiabilitiesFairValueDisclosureRecurring	79900000	USD
CY2015Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	7569800000	USD
CY2016Q3	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	7472900000	USD
CY2016Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	7892600000	USD
CY2017Q3	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	7963900000	USD
CY2016Q4	us-gaap	Liability For Future Policy Benefits LiabilityForFuturePolicyBenefits	666100000	USD
CY2017Q3	us-gaap	Liability For Future Policy Benefits LiabilityForFuturePolicyBenefits	618500000	USD
CY2016Q4	us-gaap	Liability For Future Policy Benefits And Unpaid Claims And Claims Adjustment Expense LiabilityForFuturePolicyBenefitsAndUnpaidClaimsAndClaimsAdjustmentExpense	10185500000	USD
CY2017Q3	us-gaap	Liability For Future Policy Benefits And Unpaid Claims And Claims Adjustment Expense LiabilityForFuturePolicyBenefitsAndUnpaidClaimsAndClaimsAdjustmentExpense	10507700000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	42331900000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	45998200000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	5835500000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	5932100000	USD
CY2016Q3	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	16592700000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	48318600000	USD
CY2017Q3	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	17703800000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	52439300000	USD
CY2015Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	6924200000	USD
CY2016Q3	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	7075400000	USD
CY2016Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	7353500000	USD
CY2017Q3	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	7862500000	USD
	us-gaap	Litigation Settlement Amount Awarded To Other Party LitigationSettlementAmountAwardedToOtherParty	115000000	USD
CY2016Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	928400000	USD
CY2017Q3	us-gaap	Long Term Debt Current LongTermDebtCurrent	1273400000	USD
CY2016Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	14358500000	USD
CY2017Q3	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	13777300000	USD
	us-gaap	Net Investment Income NetInvestmentIncome	627600000	USD
	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	3	segment
CY2017Q3	us-gaap	Number Of States In Which Entity Operates NumberOfStatesInWhichEntityOperates	50	states
CY2016Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	1078100000	USD
	us-gaap	Operating Income Loss OperatingIncomeLoss	4148700000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-1378000000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-2006300000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1184800000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1461700000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	2993400000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	5486000000	USD
CY2016Q3	us-gaap	Net Income Loss NetIncomeLoss	617800000	USD
	us-gaap	Net Income Loss NetIncomeLoss	2101400000	USD
CY2017Q3	us-gaap	Net Income Loss NetIncomeLoss	746900000	USD
	us-gaap	Net Income Loss NetIncomeLoss	2612100000	USD
CY2016Q3	us-gaap	Net Investment Income NetInvestmentIncome	200900000	USD
	us-gaap	Net Investment Income NetInvestmentIncome	566900000	USD
CY2017Q3	us-gaap	Net Investment Income NetInvestmentIncome	220200000	USD
CY2017Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	982000000	USD
	us-gaap	Operating Income Loss OperatingIncomeLoss	3794400000	USD
CY2016Q4	us-gaap	Other Assets Current OtherAssetsCurrent	1781800000	USD
CY2017Q3	us-gaap	Other Assets Current OtherAssetsCurrent	1822000000	USD
CY2016Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	467900000	USD
CY2017Q3	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	850900000	USD
CY2016Q3	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	63400000	USD
	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	454300000	USD
CY2017Q3	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	87600000	USD
	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	297000000	USD
CY2016Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	400000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	1000000	USD
CY2017Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	500000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	2600000	USD
CY2016Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	-300000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	-500000	USD
CY2017Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	-200000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	-1300000	USD
CY2016Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	1000000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-71300000	USD
CY2017Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	8900000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	141900000	USD
CY2016Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	1000000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-71300000	USD
CY2017Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	8900000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	141900000	USD
CY2016Q3	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-3200000	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-10800000	USD
CY2017Q3	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-4700000	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-12800000	USD
CY2016Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	58100000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	66900000	USD
CY2017Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	79000000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	107300000	USD
CY2016Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	-31300000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	-36000000	USD
CY2017Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	-42600000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	-57800000	USD
CY2016Q3	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	-3100000	USD
	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	6200000	USD
CY2017Q3	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	-6800000	USD
	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	-79200000	USD
CY2016Q3	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-17200000	USD
	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-472700000	USD
CY2017Q3	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-4900000	USD
	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-67700000	USD
CY2016Q3	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	9200000	USD
	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	254500000	USD
CY2017Q3	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	2500000	USD
	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	36400000	USD
CY2016Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	5300000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	387400000	USD
CY2017Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	8600000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	189700000	USD
CY2016Q3	us-gaap	Other Income OtherIncome	9100000	USD
	us-gaap	Other Income OtherIncome	29300000	USD
CY2017Q3	us-gaap	Other Income OtherIncome	10500000	USD
	us-gaap	Other Income OtherIncome	21500000	USD
CY2016Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	3581300000	USD
CY2017Q3	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	3788400000	USD
CY2016Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	883800000	USD
CY2017Q3	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	944000000	USD
CY2016Q4	us-gaap	Other Long Term Investments OtherLongTermInvestments	2240500000	USD
CY2017Q3	us-gaap	Other Long Term Investments OtherLongTermInvestments	2442100000	USD
CY2016Q4	us-gaap	Other Policyholder Funds OtherPolicyholderFunds	2221100000	USD
CY2017Q3	us-gaap	Other Policyholder Funds OtherPolicyholderFunds	2471700000	USD
CY2016Q4	us-gaap	Other Receivables OtherReceivables	2536600000	USD
CY2017Q3	us-gaap	Other Receivables OtherReceivables	2130200000	USD
CY2016Q4	us-gaap	Other Short Term Investments OtherShortTermInvestments	15800000	USD
CY2017Q3	us-gaap	Other Short Term Investments OtherShortTermInvestments	16900000	USD
CY2016Q3	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Period Increase Decrease OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsPeriodIncreaseDecrease	-9300000	USD
	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Period Increase Decrease OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsPeriodIncreaseDecrease	-2200000	USD
CY2017Q3	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	-4500000	USD
CY2016Q3	us-gaap	Other Than Temporary Impairment Losses Investments Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsAvailableforsaleSecurities	15100000	USD
	us-gaap	Other Than Temporary Impairment Losses Investments Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsAvailableforsaleSecurities	134100000	USD
CY2017Q3	us-gaap	Other Than Temporary Impairment Losses Investments Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsAvailableforsaleSecurities	5600000	USD
	us-gaap	Other Than Temporary Impairment Losses Investments Availableforsale Securities OtherThanTemporaryImpairmentLossesInvestmentsAvailableforsaleSecurities	22500000	USD
CY2016Q3	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	-4100000	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	-30500000	USD
CY2017Q3	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	-1600000	USD

CY2016Q3

antm

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

AccumulatedOtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax

-7900000

USD

CY2017Q3

antm

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

AccumulatedOtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax

-2400000

USD

CY2016Q3

antm

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

AvailableForSaleSecuritiesAccumulatedOtherComprehensiveIncomeNetDeferredTaxLiability

-364000000

USD

CY2017Q3

antm

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

AvailableForSaleSecuritiesAccumulatedOtherComprehensiveIncomeNetDeferredTaxLiability

-309900000

USD

CY2016Q4

antm

Available For Sale Securities Debt Maturities Amortized Cost Noncurrent

AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostNoncurrent

524600000

USD

CY2017Q3

antm

Available For Sale Securities Debt Maturities Amortized Cost Noncurrent

AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostNoncurrent

524700000

USD

CY2016Q4

antm

Available For Sale Securities Equity Securities Cost Current

AvailableForSaleSecuritiesEquitySecuritiesCostCurrent

1076100000

USD

CY2017Q3

antm

Available For Sale Securities Equity Securities Cost Current

AvailableForSaleSecuritiesEquitySecuritiesCostCurrent

1033700000

USD

CY2016Q4

antm

Available For Sale Securities Equity Securities Cost Noncurrent

AvailableForSaleSecuritiesEquitySecuritiesCostNoncurrent

27200000

USD

antm

Securities Lending Transactions Initial Collateral Percentage Value

SecuritiesLendingTransactionsInitialCollateralPercentageValue

1.02

CY2016Q3

antm

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

AvailableForSaleSecuritiesOtherThanTemporaryImpairmentsInAccumulatedOtherComprehensiveIncomeDeferredTaxLiabilityAsset

4300000

USD

CY2017Q3

antm

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

AvailableForSaleSecuritiesOtherThanTemporaryImpairmentsInAccumulatedOtherComprehensiveIncomeDeferredTaxLiabilityAsset

100000

USD

CY2017Q3

antm

Available For Sale Securities Equity Securities Cost Noncurrent

AvailableForSaleSecuritiesEquitySecuritiesCostNoncurrent

27300000

USD

CY2016Q3

antm

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

CashFlowHedgingInstrumentsAccumulatedOtherComprehensiveIncomeNetDeferredTaxAsset

298200000

USD

CY2017Q3

antm

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

CashFlowHedgingInstrumentsAccumulatedOtherComprehensiveIncomeNetDeferredTaxAsset

127100000

USD

CY2016Q3

antm

Deferred Net Actuarial Gain Loss Postretirement Benefits

DeferredNetActuarialGainLossPostretirementBenefits

-153400000

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CY2017Q3

antm

Deferred Net Actuarial Gain Loss Postretirement Benefits

DeferredNetActuarialGainLossPostretirementBenefits

-138000000

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CY2016Q3

antm

Deferred Prior Service Cost Credit Postretirement Benefit Plans

DeferredPriorServiceCostCreditPostretirementBenefitPlans

63200000

USD

CY2017Q3

antm

Deferred Prior Service Cost Credit Postretirement Benefit Plans

DeferredPriorServiceCostCreditPostretirementBenefitPlans

49500000

USD

CY2016Q3

antm

Defined Benefit Plan Accumulated Other Comprehensive Income Adjustments Net Of Tax

DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeAdjustmentsNetOfTax

-373100000

USD

CY2017Q3

antm

Defined Benefit Plan Accumulated Other Comprehensive Income Adjustments Net Of Tax

DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeAdjustmentsNetOfTax

-385300000

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CY2016Q3

antm

Defined Benefit Plan Accumulated Other Comprehensive Income Net Deferred Tax Asset

DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetDeferredTaxAsset

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CY2017Q3

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Defined Benefit Plan Accumulated Other Comprehensive Income Net Deferred Tax Asset

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CY2017Q3

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Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Per Share Amount

EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitPerShareAmount

0.01

antm

Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Per Share Amount

EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitPerShareAmount

0.10

CY2017Q3

antm

Gross Premium Tax Rate

GrossPremiumTaxRate

0.0235

CY2014Q4

antm

Increase In Stock Repurchase Program Authorization

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CY2016Q4

antm

Liability For Future Policy Benefits Current

LiabilityForFuturePolicyBenefitsCurrent

71800000

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CY2017Q3

antm

Liability For Future Policy Benefits Current

LiabilityForFuturePolicyBenefitsCurrent

72100000

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CY2017Q3

antm

Merger Agreement Termination Fee

MergerAgreementTerminationFee

1850000000

USD

antm

Net Adjustment To Additional Paid In Capital For Equity Hedge

NetAdjustmentToAdditionalPaidInCapitalForEquityHedge

900000

USD

CY2016Q3

antm

Netrealizedgainslossesonfinancialinstruments

88800000

USD

antm

Netrealizedgainslossesonfinancialinstruments

-23800000

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CY2017Q3

antm

Netrealizedgainslossesonfinancialinstruments

114700000

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antm

Netrealizedgainslossesonfinancialinstruments

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CY2017Q3

antm

Number Of Counties In Geographical Region Served As Independent Licensee

NumberOfCountiesInGeographicalRegionServedAsIndependentLicensee

10

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CY2017Q3

antm

Number Of Counties In State Of Kansas Company Does Not Serve

NumberOfCountiesInStateOfKansasCompanyDoesNotServe

30

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CY2017Q3

antm

Number Of Medical Members

NumberOfMedicalMembers

40300000

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CY2016Q3

antm

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

OtherNetChangeInUnrecognizedPeriodicBenefitCostsForDefinedBenefitPensionAndPostretirementBenefitPlansTaxBenefitExpense

-1700000

USD

antm

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

OtherNetChangeInUnrecognizedPeriodicBenefitCostsForDefinedBenefitPensionAndPostretirementBenefitPlansTaxBenefitExpense

-7000000

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CY2017Q3

antm

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

OtherNetChangeInUnrecognizedPeriodicBenefitCostsForDefinedBenefitPensionAndPostretirementBenefitPlansTaxBenefitExpense

-3000000

USD

antm

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

OtherNetChangeInUnrecognizedPeriodicBenefitCostsForDefinedBenefitPensionAndPostretirementBenefitPlansTaxBenefitExpense

-8200000

USD

antm

Payments For Proceeds From Financing Derivatives

PaymentsForProceedsFromFinancingDerivatives

1034000000

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antm

Payments For Proceeds From Financing Derivatives

PaymentsForProceedsFromFinancingDerivatives

175600000

USD

antm

Percentageofrevenuessubjecttonewrevenueguidanceunder Asc606

PercentageofrevenuessubjecttonewrevenueguidanceunderASC606

0.060

antm

Potentially Dilutive Restricted Stock Units Contingent On Operating Results

PotentiallyDilutiveRestrictedStockUnitsContingentOnOperatingResults

500000

shares

antm

Potentially Dilutive Restricted Stock Units Contingent On Operating Results

PotentiallyDilutiveRestrictedStockUnitsContingentOnOperatingResults

400000

shares

antm

Present Value Of Contract Liability Debt Issuance Costs Related To Equity Units

PresentValueOfContractLiabilityDebtIssuanceCostsRelatedToEquityUnits

300000

USD

CY2016

antm

Securities Lending Transactions Initial Collateral Percentage Value

SecuritiesLendingTransactionsInitialCollateralPercentageValue

1.02

CY2016

antm

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

SecuritiesLendingTransactionsRatioofFairValueofCollateralHeldToSecuritiesOnLoan

1.03

antm

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

SecuritiesLendingTransactionsRatioofFairValueofCollateralHeldToSecuritiesOnLoan

1.03

antm

Stock Repurchased And Retired During Period Average Price

StockRepurchasedAndRetiredDuringPeriodAveragePrice

186.80

dei

Amendment Flag

AmendmentFlag

false

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Current Fiscal Year End Date

CurrentFiscalYearEndDate

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Document Fiscal Period Focus

DocumentFiscalPeriodFocus

Q3

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Document Fiscal Year Focus

DocumentFiscalYearFocus

2017

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Document Period End Date

DocumentPeriodEndDate

2017-09-30

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Document Type

DocumentType

10-Q

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Entity Central Index Key

EntityCentralIndexKey

0001156039

CY2017Q3

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Entity Common Stock Shares Outstanding

EntityCommonStockSharesOutstanding

257404755

shares

CY2017Q4

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Entity Common Stock Shares Outstanding

EntityCommonStockSharesOutstanding

256760521

shares

dei

Entity Filer Category

EntityFilerCategory

Large Accelerated Filer

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Entity Registrant Name

EntityRegistrantName

Anthem, Inc.

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Trading Symbol

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ANTM

CY2016Q4

invest

Derivative Notional Amount

DerivativeNotionalAmount

16834900000

USD

CY2017Q3

invest

Derivative Notional Amount

DerivativeNotionalAmount

6263100000

USD

CY2016Q4

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Accounts Payable And Accrued Liabilities Current

AccountsPayableAndAccruedLiabilitiesCurrent

4014900000

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CY2017Q3

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Accounts Payable And Accrued Liabilities Current

AccountsPayableAndAccruedLiabilitiesCurrent

4454200000

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CY2016Q4

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Accrued Income Taxes Current

AccruedIncomeTaxesCurrent

0

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CY2017Q3

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Accrued Income Taxes Current

AccruedIncomeTaxesCurrent

187500000

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CY2016Q4

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Accrued Investment Income Receivable

AccruedInvestmentIncomeReceivable

164500000

USD

CY2017Q3

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Accrued Investment Income Receivable

AccruedInvestmentIncomeReceivable

158300000

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CY2016Q3

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Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax

AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax

630700000

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CY2017Q3

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Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax

AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax

550900000

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CY2016Q3

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CY2017Q3

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-236100000

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CY2016Q3

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Accumulated Other Comprehensive Income Loss Defined Benefit Pension And Other Postretirement Plans Net Of Tax

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54700000

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53900000

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CY2016Q3

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Accumulated Other Comprehensive Income Loss Foreign Currency Translation Adjustment Net Of Tax

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-5200000

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CY2017Q3

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Accumulated Other Comprehensive Income Loss Foreign Currency Translation Adjustment Net Of Tax

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CY2016Q3

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CY2016Q4

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CY2017Q3

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AccumulatedOtherComprehensiveIncomeLossNetOfTax

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CY2016Q3

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Accumulated Other Comprehensive Income Loss Other Than Temporary Impairment Not Credit Loss Net Of Tax Availableforsale Debt Securities

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12100000

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CY2017Q3

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AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxAvailableforsaleDebtSecurities

200000

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CY2016Q3

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Accumulated Other Comprehensive Income Loss Other Than Temporary Impairment Not Credit Loss Net Of Tax Debt Securities

AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities

7800000

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CY2017Q3

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Accumulated Other Comprehensive Income Loss Other Than Temporary Impairment Not Credit Loss Net Of Tax Debt Securities

AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities

100000

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CY2016Q4

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Additional Paid In Capital

AdditionalPaidInCapital

8805100000

USD

CY2017Q3

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Additional Paid In Capital

AdditionalPaidInCapital

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USD

us-gaap

Adjustment For Amortization

AdjustmentForAmortization

601700000

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us-gaap

Adjustment For Amortization

AdjustmentForAmortization

581200000

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us-gaap

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

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-1100000

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CY2016Q3

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Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

47400000

USD

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

145700000

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CY2017Q3

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

41900000

USD

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

124300000

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CY2016Q3

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Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount

AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

2500000

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us-gaap

Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount

AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

2300000

shares

us-gaap

Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount

AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

500000

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CY2016Q4

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Assets

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CY2017Q3

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Assets

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CY2016Q4

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Assets Current

AssetsCurrent

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CY2017Q3

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Assets Current

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36973700000

USD

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

9.70

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Effect Of Exchange Rate On Cash And Cash Equivalents

EffectOfExchangeRateOnCashAndCashEquivalents

1900000

USD

CY2016Q4

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Assets Fair Value Disclosure Recurring

AssetsFairValueDisclosureRecurring

22587700000

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CY2017Q3

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Assets Fair Value Disclosure Recurring

AssetsFairValueDisclosureRecurring

25773200000

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CY2016Q3

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Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax

AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax

1068900000

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CY2017Q3

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Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax

AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax

940900000

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CY2016Q3

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Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax

AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax

74200000

USD

CY2017Q3

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Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax

AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax

80100000

USD

CY2016Q4

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Available For Sale Debt Securities Amortized Cost Basis

AvailableForSaleDebtSecuritiesAmortizedCostBasis

16991800000

USD

CY2017Q3

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Available For Sale Debt Securities Amortized Cost Basis

AvailableForSaleDebtSecuritiesAmortizedCostBasis

18269000000

USD

CY2016Q4

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Available For Sale Securities

AvailableForSaleSecurities

19187400000

USD

CY2017Q3

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Available For Sale Securities

AvailableForSaleSecurities

20715500000

USD

CY2016Q4

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Available For Sale Securities Accumulated Gross Unrealized Gain Before Tax

AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax

748600000

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CY2017Q3

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Available For Sale Securities Accumulated Gross Unrealized Gain Before Tax

AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax

940900000

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CY2016Q3

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Available For Sale Securities Accumulated Gross Unrealized Gain Loss Before Tax

AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainLossBeforeTax

994700000

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CY2017Q3

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Available For Sale Securities Accumulated Gross Unrealized Gain Loss Before Tax

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860800000

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CY2016Q4

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Available For Sale Securities Amortized Cost

AvailableForSaleSecuritiesAmortizedCost

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CY2017Q3

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Available For Sale Securities Amortized Cost

AvailableForSaleSecuritiesAmortizedCost

19854700000

USD

CY2016Q4

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Available For Sale Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss

AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss

42400000

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CY2017Q3

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss

AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss

32700000

USD

CY2016Q4

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss

AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss

138500000

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CY2017Q3

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss

AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss

47400000

USD

CY2016Q4

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value

AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue

6220300000

USD

CY2017Q3

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value

AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue

3662900000

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CY2016Q4

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value

AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue

816000000

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CY2017Q3

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value

AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue

1127900000

USD

CY2016Q4

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Available For Sale Securities Debt Securities Current

AvailableForSaleSecuritiesDebtSecuritiesCurrent

17163100000

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CY2017Q3

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Available For Sale Securities Debt Securities Current

AvailableForSaleSecuritiesDebtSecuritiesCurrent

18697300000

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CY2016Q4

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Available For Sale Securities Debt Securities Noncurrent

AvailableForSaleSecuritiesDebtSecuritiesNoncurrent

524400000

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CY2017Q3

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Available For Sale Securities Debt Securities Noncurrent

AvailableForSaleSecuritiesDebtSecuritiesNoncurrent

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CY2016Q4

us-gaap

Available For Sale Securities Equity Securities Current

AvailableForSaleSecuritiesEquitySecuritiesCurrent

1468500000

USD

CY2017Q3

us-gaap

Available For Sale Securities Equity Securities Current

AvailableForSaleSecuritiesEquitySecuritiesCurrent

1452600000

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CY2016Q4

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Available For Sale Securities Equity Securities Noncurrent

AvailableForSaleSecuritiesEquitySecuritiesNoncurrent

31400000

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CY2017Q3

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Available For Sale Securities Equity Securities Noncurrent

AvailableForSaleSecuritiesEquitySecuritiesNoncurrent

32300000

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CY2016Q3

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Available For Sale Securities Gross Realized Gains

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us-gaap

Available For Sale Securities Gross Realized Gains

AvailableForSaleSecuritiesGrossRealizedGains

343200000

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CY2017Q3

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Available For Sale Securities Gross Realized Gains

AvailableForSaleSecuritiesGrossRealizedGains

144400000

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us-gaap

Available For Sale Securities Gross Realized Gains

AvailableForSaleSecuritiesGrossRealizedGains

255100000

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CY2016Q3

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us-gaap

Available For Sale Securities Gross Realized Losses

AvailableForSaleSecuritiesGrossRealizedLosses

136700000

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CY2017Q3

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Available For Sale Securities Gross Realized Losses

AvailableForSaleSecuritiesGrossRealizedLosses

17200000

USD

us-gaap

Available For Sale Securities Gross Realized Losses

AvailableForSaleSecuritiesGrossRealizedLosses

67500000

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CY2016Q4

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Available For Sale Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions Less Than One Year

AvailableForSaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsLessThanOneYear

3330

securities

CY2017Q3

us-gaap

Available For Sale Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions Less Than One Year

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1968

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CY2016Q3

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

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-36700000

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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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CY2017Q3

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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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CY2016Q4

us-gaap

Availableforsale Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions Greater Than Or Equal To One Year

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425

securities

CY2017Q3

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Availableforsale Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions Greater Than Or Equal To One Year

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648

securities

CY2016Q3

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Benefits Losses And Expenses

BenefitsLossesAndExpenses

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us-gaap

Benefits Losses And Expenses

BenefitsLossesAndExpenses

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CY2017Q3

us-gaap

Benefits Losses And Expenses

BenefitsLossesAndExpenses

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USD

us-gaap

Benefits Losses And Expenses

BenefitsLossesAndExpenses

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CY2015Q4

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Cash And Cash Equivalents At Carrying Value

CashAndCashEquivalentsAtCarryingValue

2113500000

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CY2016Q3

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Cash And Cash Equivalents At Carrying Value

CashAndCashEquivalentsAtCarryingValue

2546000000

USD

CY2016Q4

us-gaap

Cash And Cash Equivalents At Carrying Value

CashAndCashEquivalentsAtCarryingValue

4075300000

USD

CY2017Q3

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Cash And Cash Equivalents At Carrying Value

CashAndCashEquivalentsAtCarryingValue

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CY2016Q4

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Cash And Cash Equivalents Fair Value Disclosure

CashAndCashEquivalentsFairValueDisclosure

1546000000

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CY2017Q3

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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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432500000

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Cash And Cash Equivalents Period Increase Decrease

CashAndCashEquivalentsPeriodIncreaseDecrease

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Ceded Premiums Payable

CededPremiumsPayable

645600000

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CY2016Q3

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Ceded Premiums Payable

CededPremiumsPayable

397500000

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CY2016Q4

us-gaap

Ceded Premiums Payable

CededPremiumsPayable

539100000

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CY2017Q3

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Ceded Premiums Payable

CededPremiumsPayable

101400000

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CY2016Q4

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Commitments And Contingencies

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Commitments And Contingencies

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CY2016Q1

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Common Stock Dividends Per Share Cash Paid