Goodwill and Other Intangibles	9 Months Ended
Goodwill and Other Intangibles	Sep. 30, 2011
Goodwill and Other Intangibles [Abstract]
Goodwill and Other Intangibles	I. Goodwill and Other Intangibles There were no changes in the goodwill balance of $186 million during the nine months ended September 30, 2011. In the third quarter of 2010, management reached a decision to de-emphasize the sale of supplemental health insurance products through career agents, including the sale of a marketing subsidiary. As a result of this decision, AFG performed an interim impairment test of the goodwill associated with the reporting unit using an income valuation method based on discounted cash flows. Based on the results of this test, AFG recorded a goodwill impairment charge of $22 million (included in realized gains (losses) on subsidiaries) to write off all of the goodwill related to this reporting unit. Included in other assets in AFG’s Balance Sheet is $40 million at September 30, 2011 and $49 million at December 31, 2010, in amortizable intangible assets related to property and casualty insurance acquisitions. These amounts are net of accumulated amortization of $44 million and $35 million, respectively. Amortization of these intangibles was $3 million in the third quarter and $9 million during the first nine months of both 2011 and 2010. Other assets also include $8 million in non-amortizable intangible assets related to insurance licenses acquired in the acquisition of Vanliner in 2010.

The entire disclosure for the aggregate amount of goodwill and a description of intangible assets, which may include (a) for amortizable intangible assets (also referred to as finite-lived intangible assets), the carrying amount, the amount of any significant residual value, and the weighted-average amortization period, (b) for intangible assets not subject to amortization (also referred to as indefinite-lived intangible assets), the carrying amount, and (c) the amount of research and development assets acquired and written off in the period, including the line item in the income statement in which the amounts written off are aggregated, if not readily apparent from the income statement. Also discloses (a) for amortizable intangibles assets in total and by major class, the gross carrying amount and accumulated amortization, the total amortization expense for the period, and the estimated aggregate amortization expense for each of the five succeeding fiscal years, (b) for intangible assets not subject to amortization the carrying amount in total and by major class, and (c) for goodwill, in total and for each reportable segment, the changes in the carrying amount of goodwill during the period (including the aggregate amount of goodwill acquired, the aggregate amount of impairment losses recognized, and the amount of goodwill included in the gain (loss) on disposal of a reporting unit). If any part of goodwill has not been allocated to a reportable segment, discloses the unallocated amount and the reasons for not allocating. For each impairment loss recognized related to an intangible asset (excluding goodwill), discloses: (a) a description of the impaired intangible asset and the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method for determining fair value, (c) the caption in the income statement or the statement of activities in which the impairment loss is aggregated, and (d) the segment in which the impaired intangible asset is reported. For each goodwill impairment loss recognized, discloses: (a) a description of the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method of determining the fair value of the associated reporting unit, and (c) if a recognized impairment loss is an estimate not finalized and the reasons why the estimate is not final. May also disclose the nature and amount of any significant adjustments made to a previous estimate of an impairment loss.