Condensed Financial Information of Parent Company (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues:
Total revenues	$ 1,529	$ 1,581	$ 1,392	$ 1,211	$ 1,362	$ 1,443	$ 1,139	$ 1,148	$ 5,713	$ 5,092	$ 4,957
Costs and Expenses:
Other expenses									281	326	326
Total costs and expenses									5,087	4,403	4,420
Earnings before income taxes									626	689	537
Provision for income taxes									220	236	135
Net Earnings Attributable to Shareholders	127	116	106	103	158	83	110	120	452	471	488
AFG [Member]
Revenues:
Dividends from subsidiaries									480	606	433
Equity in undistributed earnings of subsidiaries									332	260	325
Investment and other income									5	8	5
Total revenues									817	874	763
Costs and Expenses:
Interest charges on intercompany borrowings									10	10	11
Interest charges on other borrowings									69	67	61
Other expenses									66	90	68
Total costs and expenses									145	167	140
Earnings before income taxes									672	707	623
Provision for income taxes									220	236	135
Net Earnings Attributable to Shareholders									$ 452	$ 471	$ 488