Condensed Financial Statements Of Parent Company Condensed Balance Sheets (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Investments
Fixed maturities, at fair value	$ 9,460	$ 9,121
Equity securities, at fair value	4,858	4,375
Other invested assets	68	68
Total investments	14,386	13,564
Cash and cash equivalents	591	433	487	438
Investment income receivable	123	121
Land, building and equipment, net, for company use (accumulated depreciation: 2014—$112; 2013—$106)	194	210
Other assets	75	73
Total assets	18,753	17,662
Liabilities
Deferred federal income tax	840	673
Long-term debt	791	790
Other liabilities	648	611
Total liabilities	12,180	11,592
Shareholders' Equity
Common stock	397	397
Paid-in capital	1,214	1,191
Retained earnings	4,505	4,268
Accumulated other comprehensive income	1,744	1,504
Treasury stock at cost	(1,287)	(1,290)
Total shareholders' equity	6,573	6,070	5,453	5,033
Total liabilities and shareholders' equity	18,753	17,662
Cincinnati Financial Corporation
Investments
Fixed maturities, at fair value	69	75
Equity securities, at fair value	1,643	1,366
Other invested assets	37	32
Total investments	1,749	1,473
Cash and cash equivalents	72	91	90	20
Equity in net assets of subsidiaries	5,627	5,351
Investment income receivable	6	5
Land, building and equipment, net, for company use (accumulated depreciation: 2014—$112; 2013—$106)	144	148
Prepaid income tax	0	2
Other assets	23	24
Due from subsidiaries	107	114
Total assets	7,728	7,208
Liabilities
Dividends declared but unpaid	72	68
Deferred federal income tax	216	185
Long-term debt	791	790
Other liabilities	76	95
Total liabilities	1,155	1,138
Shareholders' Equity
Common stock	397	397
Paid-in capital	1,214	1,191
Retained earnings	4,505	4,268
Accumulated other comprehensive income	1,744	1,504
Treasury stock at cost	(1,287)	(1,290)
Total shareholders' equity	6,573	6,070
Total liabilities and shareholders' equity	$ 7,728	$ 7,208