Equity (Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 57,768	$ 48,326
Net other comprehensive income (loss)	(19)	19
Ending balance	58,936	52,123
Net Unrealized Gains (Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	22	20
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from AOCI	0	1
Net other comprehensive income (loss)	0	1
Less other comprehensive (income) loss attributable to noncontrolling interests	0	0
Ending balance	22	21
Net Unrealized Gains (Losses) on Available for Sale Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(39)	(69)
Other comprehensive income (loss) before reclassifications	(6)	9
Amounts reclassified from AOCI	1	5
Net other comprehensive income (loss)	(5)	14
Less other comprehensive (income) loss attributable to noncontrolling interests	0	0
Ending balance	(44)	(55)
Defined Benefit Pension and Other Benefits Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(79)	(101)
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from AOCI	0	1
Net other comprehensive income (loss)	0	1
Less other comprehensive (income) loss attributable to noncontrolling interests	0	0
Ending balance	(79)	(100)
Net Unrealized Gains (Losses) on Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(64)	(74)
Other comprehensive income (loss) before reclassifications	(14)	3
Amounts reclassified from AOCI	0	0
Net other comprehensive income (loss)	(14)	3
Less other comprehensive (income) loss attributable to noncontrolling interests	5	(1)
Ending balance	(73)	(72)
Other Comprehensive Income Related to Equity Method Investees
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	7	6
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from AOCI	0	0
Net other comprehensive income (loss)	0	0
Less other comprehensive (income) loss attributable to noncontrolling interests	0	0
Ending balance	7	6
Total
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(153)	(218)
Other comprehensive income (loss) before reclassifications	(20)	12
Amounts reclassified from AOCI	1	7
Net other comprehensive income (loss)	(19)	19
Less other comprehensive (income) loss attributable to noncontrolling interests	5	(1)
Ending balance	(167)	(200)
Net unrealized gains (losses) on cash flow hedges. noncontrolling interest
Accumulated Other Comprehensive Income (Loss) [Line Items]
Ending balance	0	0
Net unrealized gains (losses) on available for sale securities, noncontrolling interest
Accumulated Other Comprehensive Income (Loss) [Line Items]
Ending balance	0	0
Defined benefit pension and other benefits plans, noncontrolling interest
Accumulated Other Comprehensive Income (Loss) [Line Items]
Ending balance	0	0
Net unrealized gains (losses) on foreign currency translation, noncontrolling interest
Accumulated Other Comprehensive Income (Loss) [Line Items]
Ending balance	(15)	(13)
Other comprehensive income (loss) related to equity method investees, noncontrolling interest
Accumulated Other Comprehensive Income (Loss) [Line Items]
Ending balance	0	0
Total, noncontrolling interest
Accumulated Other Comprehensive Income (Loss) [Line Items]
Ending balance	$ (15)	$ (13)