Reinsurance - Schedule of Short-Duration Insurance Premiums Written and Earned (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Premiums earned:
Direct	$ 31,463	$ 31,208	$ 30,781
Assumed	3,747	3,947	7,050
Ceded	(11,459)	(11,618)	(12,267)
Net	23,751	23,537	25,564
Short-Duration Insurance
Premiums written:
Direct	31,808	31,743	31,445
Assumed	3,796	3,950	7,951
Ceded	(11,931)	(11,791)	(12,190)
Net	23,673	23,902	27,206
Premiums earned:
Direct	31,463	31,208	30,781
Assumed	3,747	3,947	7,050
Ceded	(11,459)	(11,618)	(12,267)
Net	$ 23,751	$ 23,537	$ 25,564
Percent of amount assumed to net	15.80%	16.80%	27.60%