XML 72 R57.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Investments - Available for sale fixed maturities (Details) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | ---
Debt Securities, Available-for-sale [Line Items] |  |
Fixed maturities, Available for sale, Amortized Cost | $ 41,837 | $ 37,038
Available for sale (AFS) fixed maturities | 41,997 | 38,379
Total fixed maturities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fixed maturities, Available for sale, Amortized Cost | 41,837 | 37,038
Fixed maturities, Available for sale, Gross Unrealized, Gains | 763 | 1,423
Fixed maturities, Available for sale, Gross Unrealized, Losses | (603) | (82)
Fixed maturities, Available for sale, Net Unrealized, Gains (Losses) | 160 | 1,341
Available for sale (AFS) fixed maturities | 41,997 | 38,379
U.S. Government and government agencies |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fixed maturities, Available for sale, Amortized Cost | 235 | 244
Fixed maturities, Available for sale, Gross Unrealized, Gains | 1 | 1
Fixed maturities, Available for sale, Gross Unrealized, Losses | (3) | (3)
Fixed maturities, Available for sale, Net Unrealized, Gains (Losses) | (2) | (2)
Available for sale (AFS) fixed maturities | 233 | 242
States, municipalities and political subdivisions |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fixed maturities, Available for sale, Amortized Cost | 6,825 | 6,887
Fixed maturities, Available for sale, Gross Unrealized, Gains | 169 | 254
Fixed maturities, Available for sale, Gross Unrealized, Losses | (55) | (18)
Fixed maturities, Available for sale, Net Unrealized, Gains (Losses) | 114 | 236
Available for sale (AFS) fixed maturities | 6,939 | 7,123
Foreign government |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fixed maturities, Available for sale, Amortized Cost | 140 | 124
Fixed maturities, Available for sale, Gross Unrealized, Gains | 2 | 3
Fixed maturities, Available for sale, Gross Unrealized, Losses | 0 | 0
Fixed maturities, Available for sale, Net Unrealized, Gains (Losses) | 2 | 3
Available for sale (AFS) fixed maturities | 142 | 127
Residential MBS |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fixed maturities, Available for sale, Amortized Cost | 2,476 | 2,884
Fixed maturities, Available for sale, Gross Unrealized, Gains | 277 | 349
Fixed maturities, Available for sale, Gross Unrealized, Losses | (9) | (6)
Fixed maturities, Available for sale, Net Unrealized, Gains (Losses) | 268 | 343
Available for sale (AFS) fixed maturities | 2,744 | 3,227
Commercial MBS |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fixed maturities, Available for sale, Amortized Cost | 905 | 927
Fixed maturities, Available for sale, Gross Unrealized, Gains | 17 | 36
Fixed maturities, Available for sale, Gross Unrealized, Losses | (2) | (1)
Fixed maturities, Available for sale, Net Unrealized, Gains (Losses) | 15 | 35
Available for sale (AFS) fixed maturities | 920 | 962
Asset-backed securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fixed maturities, Available for sale, Amortized Cost | 9,781 | 7,836
Fixed maturities, Available for sale, Gross Unrealized, Gains | 130 | 142
Fixed maturities, Available for sale, Gross Unrealized, Losses | (100) | (16)
Fixed maturities, Available for sale, Net Unrealized, Gains (Losses) | 30 | 126
Available for sale (AFS) fixed maturities | 9,811 | 7,962
Corporate and other |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fixed maturities, Available for sale, Amortized Cost | 21,475 | 18,136
Fixed maturities, Available for sale, Gross Unrealized, Gains | 167 | 638
Fixed maturities, Available for sale, Gross Unrealized, Losses | (434) | (38)
Fixed maturities, Available for sale, Net Unrealized, Gains (Losses) | (267) | 600
Available for sale (AFS) fixed maturities | $ 21,208 | $ 18,736

X
- Definition Amount before tax of net unrealized gain (loss) in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale. + References No definition available. + Details
Name: | afg_AvailableforsaleDebtSecuritiesAccumulatedNetUnrealizedGainLossbeforeTax
Namespace Prefix: | afg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109979856&loc=d3e26610-111562 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_FixedMaturitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USTreasuryAndGovernmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_ForeignGovernmentDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |