Additional Information	12 Months Ended
Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Additional Information	Additional Information Allowance for Uncollectible Reinsurance AFG’s aggregate allowance for uncollectible reinsurance recoverables was $18 million at December 31, 2018 and $20 million at December 31, 2017. AFG reviews the allowance quarterly and adjusts it as necessary to reflect changes in estimates of uncollectible balances. AFG recorded net expense reductions against the allowance of $2 million in 2018 and less than $1 million in both 2017 and 2016. In 2017, the allowance was reduced by reinsurance recoverable write-offs of $2 million. Operating Leases Total rental expense for various leases of office space and equipment was $70 million in 2018, $69 million in 2017 and $67 million in 2016. Future minimum rentals, related principally to office space, required under operating leases having initial or remaining noncancelable lease terms in excess of one year at December 31, 2018, were as follows: 2019 – $65 million; 2020 – $57 million; 2021 – $50 million; 2022 – $40 million; 2023 – $35 million; and $79 million thereafter. Financial Instruments — Unfunded Commitments On occasion, AFG and its subsidiaries have entered into financial instrument transactions that may present off-balance-sheet risks of both a credit and market risk nature. These transactions include commitments to fund loans, loan guarantees and commitments to purchase and sell securities or loans. At December 31, 2018, AFG and its subsidiaries had commitments to fund credit facilities and contribute capital to limited partnerships and limited liability corporations of approximately $949 million. Benefit Plans AFG expensed approximately $37 million in 2018, $45 million in 2017 and $43 million in 2016 for its retirement and employee savings plans.

Additional Information

Allowance for Uncollectible Reinsurance AFG’s aggregate allowance for uncollectible reinsurance recoverables was $18 million at December 31, 2018 and $20 million at December 31, 2017. AFG reviews the allowance quarterly and adjusts it as necessary to reflect changes in estimates of uncollectible balances. AFG recorded net expense reductions against the allowance of $2 million in 2018 and less than $1 million in both 2017 and 2016. In 2017, the allowance was reduced by reinsurance recoverable write-offs of $2 million.

Operating Leases Total rental expense for various leases of office space and equipment was $70 million in 2018, $69 million in 2017 and $67 million in 2016. Future minimum rentals, related principally to office space, required under operating leases having initial or remaining noncancelable lease terms in excess of one year at December 31, 2018, were as follows: 2019 – $65 million; 2020 – $57 million; 2021 – $50 million; 2022 – $40 million; 2023 – $35 million; and $79 million thereafter.

Financial Instruments — Unfunded Commitments On occasion, AFG and its subsidiaries have entered into financial instrument transactions that may present off-balance-sheet risks of both a credit and market risk nature. These transactions include commitments to fund loans, loan guarantees and commitments to purchase and sell securities or loans. At December 31, 2018, AFG and its subsidiaries had commitments to fund credit facilities and contribute capital to limited partnerships and limited liability corporations of approximately $949 million.

Benefit Plans AFG expensed approximately $37 million in 2018, $45 million in 2017 and $43 million in 2016 for its retirement and employee savings plans.