Condensed Financial Statements Of Parent Company Condensed Statements Of Income (Details) (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
Investment income, net of expenses									$ 549	$ 529	$ 531
Realized investment gains, net									133	83	42
Other revenues									8	9	10
Total revenues	1,262	1,280	1,214	1,189	1,172	1,152	1,104	1,103	4,945	4,531	4,111
Expenses
Interest expense									53	54	54
Other expenses									14	15	14
Total expenses									4,224	3,817	3,545
Income (Loss) Before Income Taxes and Earnings of Subsidiaries	236	259	107	119	167	182	148	217	721	714	566
Benefit for income taxes									196	197	145
Net Income	167	183	84	91	122	131	110	154	525	517	421
Cincinnati Financial Corporation
Revenues
Investment income, net of expenses									46	41	42
Realized investment gains, net									34	21	34
Other revenues									16	15	15
Total revenues									96	77	91
Expenses
Interest expense									52	53	53
Other expenses									28	29	27
Total expenses									80	82	80
Income (Loss) Before Income Taxes and Earnings of Subsidiaries									16	(5)	11
Benefit for income taxes									(5)	(11)	(4)
Net Income Before Earnings of Subsidiaries									21	6	15
Increase in equity of subsidiaries									504	511	406
Net Income									$ 525	$ 517	$ 421