Equity - Other comprehensive income reclassification adjustments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Other Comprehensive Income (Loss) Reclassification Adjustments
Other comprehensive income (loss)	$ (12,767)	$ 3,742	$ (26,415)	$ (3,303)
Noncontrolling interests
Other Comprehensive Income (Loss) Reclassification Adjustments
Unrealized change arising during period	(15,251)	4,938	(31,556)	(3,628)
Less: Reclassification adjustments included in net income	(611)	124	(758)	501
Total other comprehensive income (loss), before income tax expense (benefit)	(14,640)	4,814	(30,798)	(4,129)
Less: Income tax expense (benefit)	(1,873)	1,072	(4,383)	(826)
Unrealized Appreciation (Depreciation) of Fixed Maturity Securities on Which Allowance for Credit Losses Was Taken
Other Comprehensive Income (Loss) Reclassification Adjustments
Unrealized change arising during period	41	4	(16)	41
Less: Reclassification adjustments included in net income	(8)	(4)	(8)	(6)
Total other comprehensive income (loss), before income tax expense (benefit)	49	8	(8)	47
Less: Income tax expense (benefit)	9	4	(3)	10
Other comprehensive income (loss)	40	4	(5)	37
Unrealized Appreciation (Depreciation) of All Other Investments
Other Comprehensive Income (Loss) Reclassification Adjustments
Unrealized change arising during period	(15,086)	4,906	(31,337)	(3,855)
Less: Reclassification adjustments included in net income	(596)	139	(735)	530
Total other comprehensive income (loss), before income tax expense (benefit)	(14,490)	4,767	(30,602)	(4,385)
Less: Income tax expense (benefit)	(1,952)	1,057	(4,457)	(896)
Other comprehensive income (loss)	(12,538)	3,710	(26,145)	(3,489)
Foreign Currency Translation Adjustments
Other Comprehensive Income (Loss) Reclassification Adjustments
Unrealized change arising during period	(204)	25	(205)	195
Less: Reclassification adjustments included in net income	0	0	0	0
Total other comprehensive income (loss), before income tax expense (benefit)	(204)	25	(205)	195
Less: Income tax expense (benefit)	77	11	81	56
Other comprehensive income (loss)	(281)	14	(286)	139
Retirement Plan Liabilities Adjustment
Other Comprehensive Income (Loss) Reclassification Adjustments
Unrealized change arising during period	2	3	6	(8)
Less: Reclassification adjustments included in net income	(7)	(11)	(15)	(23)
Total other comprehensive income (loss), before income tax expense (benefit)	9	14	21	15
Less: Income tax expense (benefit)	(7)	0	(4)	4
Other comprehensive income (loss)	16	14	25	11
Fair Value of Liabilities Under Fair Value Option Attributable to Changes in Own Credit Risk
Other Comprehensive Income (Loss) Reclassification Adjustments
Unrealized change arising during period	(4)	0	(4)	(1)
Less: Reclassification adjustments included in net income	0	0	0	0
Total other comprehensive income (loss), before income tax expense (benefit)	(4)	0	(4)	(1)
Less: Income tax expense (benefit)	0	0	0	0
Other comprehensive income (loss)	$ (4)	$ 0	$ (4)	$ (1)