Critical Accounting Estimates and Judgment in Applying Accounting Policies - Sensitivity Analysis of GPV to Changes in Various Underwriting Risks Explanatory (Detail) - United States [member] - Long term care products [member] - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Sensitivity Analysis Of GPV To Changes In Various Underwriting Risks [Line Items]
5% decrease in the utilization rates	€ (222)	€ (201)
5% increase in the utilization rates	208	195
10% decrease expected mortality	129	122
10% increase expected mortality	€ (123)	€ (114)