Reserve for Unpaid Losses and Loss Adjustment Expenses - P&C Liabilities for Unpaid Losses and Loss Adjustment Expense (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	Dec. 31, 2020
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Beginning liabilities for unpaid losses and loss adjustment expenses, gross	$ 39,659
Less: payments
Ending liabilities for unpaid losses and loss adjustment expenses, gross	40,032
Property, Liability and Casualty Insurance Product Line
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Beginning liabilities for unpaid losses and loss adjustment expenses, gross	31,449	$ 29,622
Reinsurance and other recoverables	6,212	5,905	$ 6,081	$ 5,725
Beginning liabilities for unpaid losses and loss adjustment expenses, net	25,723	24,677	$ 25,368	$ 23,897
Provision for unpaid losses and loss adjustment expense
Current accident year	3,998	3,838
Prior accident year development [1]	(94)	80
Total provision for unpaid losses and loss adjustment expenses	3,904	3,918
Less: payments
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Current Year	(840)	(864)
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Prior Years	(2,680)	(2,222)
Total payments	(3,520)	(3,086)
Foreign currency adjustment	(29)	(7)
Ending liabilities for unpaid losses and loss adjustment expenses, net	25,723	24,677
Ending liabilities for unpaid losses and loss adjustment expenses, gross	31,935	30,582
Property, Liability and Casualty Insurance Product Line | Reinsurance Contract [Axis]: Adverse Development Cover Navigators Group
Provision for unpaid losses and loss adjustment expense
Deferred Revenue	$ 0	$ 45