Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Taxes Disclosure [Line Items]
Valuation allowances for potential capital losses	$ 8.4
Unrecognized tax benefits income tax penalties and interest expense recognized	18.1	$ 8.9	$ 1.7
Recognized liability for interest and penalties	134.5	116.2	107.4
Decrease in unrecognized tax benefits within the next twelve months	400.0
Increase in unrecognized tax benefits within the next twelve months	20.0
Amount of potential additional income tax expense related to an IRS notice of proposed adjustment subject to interest and penalties.	370.0
Tax benefit related to Swiss Agreement	$ 112.3	$ 53.5	$ (96.0)
State examination period after notification	up to one year
Minimum
Income Taxes Disclosure [Line Items]
State jurisdictions statutes of limitation period	3 years
Maximum [Member]
Income Taxes Disclosure [Line Items]
State jurisdictions statutes of limitation period	5 years
Tax Reform and AHV Financing [Member]
Income Taxes Disclosure [Line Items]
Tax benefit related to Swiss Agreement	$ (59.0)
Tax benefit associated with closing certain tax years	$ (22.0)