Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Income Tax Contingency
Tax at statutory rate, percentage	21.00%	21.00%	21.00%	21.00%
Deferred tax assets valuation allowance	$ 0		$ 0		$ 0
Cincinnati Global
Income Tax Contingency
Decrease in deferred tax assets	7		4
Decrease in deferred tax valuation allowance	7		4
Net deferred tax assets	49		49
Deferred tax assets valuation allowance	49		49
Cincinnati Global | United States
Income Tax Contingency
Operating loss carryforwards	6		6		8
Cincinnati Global | United Kingdom
Income Tax Contingency
Operating loss carryforwards	$ 123		$ 123		$ 130