Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosures
Income tax refund received	$ 0	$ 0	$ 0
Net deferred tax assets, valuation allowance	31	53
Release of unrecognized tax benefits during the year	34	0	0
United States
Income Tax Disclosures
Operating Loss Carryforwards	0	0
Cincinnati Global
Income Tax Disclosures
Net deferred tax assets	31
Net deferred tax assets, valuation allowance	31	53	56	$ 41
Decrease of deferred tax asset valuation allowance	(22)	(3)	$ 15
Cincinnati Global
Income Tax Disclosures
Decrease of deferred tax assets	22
Decrease of deferred tax asset valuation allowance	22
Cincinnati Global | United States
Income Tax Disclosures
Operating Loss Carryforwards	5	8
Cincinnati Global | United Kingdom
Income Tax Disclosures
Operating Loss Carryforwards	$ 109	$ 130