Condensed Financial Statements Of Parent Company Condensed Statements Of Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash Flows From Operating Activities
Net Income	$ 2,946	$ 1,216	$ 1,997
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	93	81	72
Investment gains and losses, net	(2,353)	(851)	(1,640)
Changes in:
Investment income receivable	(8)	(3)	(1)
Current income tax receivable/payable	(25)	44	92
Other assets	(11)	(26)	(22)
Net cash provided by operating activities	1,981	1,491	1,208
Cash Flows From Investing Activities
Sale of fixed maturities	118	179	102
Call or maturity of fixed maturities	1,343	912	1,241
Sale of equity securities	136	515	203
Purchase of fixed maturities	(2,388)	(1,382)	(1,742)
Purchase of equity securities	(313)	(699)	(382)
Investment in buildings and equipment	(15)	(20)	(24)
Change in other invested assets, net	64	(50)	(72)
Net cash (used in) received from investing activities	(1,057)	(560)	(679)
Cash Flows From Financing Activities
Payment of cash dividends to shareholders	(395)	(375)	(355)
Shares acquired - share repurchase authorization	(144)	(261)	(67)
Proceeds from stock options exercised	13	7	11
Other	(98)	(110)	(54)
Net cash used in financing activities	(685)	(798)	(546)
Cash and cash equivalents at beginning of year	900	767	784
Cash and cash equivalents at end of year	1,139	900	767
Cincinnati Financial Corporation
Cash Flows From Operating Activities
Net Income	2,946	1,216	1,997
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	11	12	10
Investment gains and losses, net	(1,034)	(552)	(720)
Dividends from subsidiaries	598	550	625
Changes in:
Increase in equity of subsidiaries	(2,084)	(763)	(1,414)
Investment income receivable	(1)	(1)	(1)
Current federal income taxes	6	(3)	(1)
Current income tax receivable/payable	220	91	146
Other assets	5	0	4
Other liabilities	0	1	4
Intercompany receivable for operations	5	34	20
Net cash provided by operating activities	672	585	670
Cash Flows From Investing Activities
Sale of fixed maturities	4	0	3
Call or maturity of fixed maturities	18	1	21
Sale of equity securities	25	307	122
Purchase of fixed maturities	(19)	(23)	(39)
Purchase of equity securities	(82)	(372)	(237)
Investment in buildings and equipment	(6)	(11)	(13)
Cash paid for acquisition	0	0	63
Change in other invested assets, net	108	(42)	(67)
Net cash (used in) received from investing activities	48	(140)	(273)
Cash Flows From Financing Activities
Payment of cash dividends to shareholders	(395)	(375)	(355)
Shares acquired - share repurchase authorization	(144)	(261)	(67)
Proceeds from stock options exercised	13	7	11
Other	1	3	2
Net cash used in financing activities	(525)	(626)	(409)
Net change in cash and cash equivalents	195	(181)	(12)
Cash and cash equivalents at beginning of year	16	197	209
Cash and cash equivalents at end of year	$ 211	$ 16	$ 197