Equity (Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 45,424	$ 44,929
Total other comprehensive loss, net of tax	(14)	(2)
Ending balance	44,049	45,730
Net Unrealized Gains (Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	14	8
Other comprehensive income before reclassifications	0	0
Amounts reclassified from AOCI	4	2
Total other comprehensive loss, net of tax	4	2
Less other comprehensive income attributable to noncontrolling interests	0	0
Ending balance	18	10
Net Unrealized Gains (Losses) on Available for Sale Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	5	20
Other comprehensive income before reclassifications	(30)	(8)
Amounts reclassified from AOCI	0	(3)
Total other comprehensive loss, net of tax	(30)	(11)
Less other comprehensive income attributable to noncontrolling interests	0	0
Ending balance	(25)	9
Defined Benefit Pension and Other Benefits Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	25	(75)
Other comprehensive income before reclassifications	0	0
Amounts reclassified from AOCI	0	1
Total other comprehensive loss, net of tax	0	1
Less other comprehensive income attributable to noncontrolling interests	0	0
Ending balance	25	(74)
Net Unrealized Gains (Losses) on Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(49)	(49)
Other comprehensive income before reclassifications	12	6
Amounts reclassified from AOCI	0	0
Total other comprehensive loss, net of tax	12	6
Less other comprehensive income attributable to noncontrolling interests	6	(2)
Ending balance	(43)	(45)
Other Comprehensive Income (Loss) Related to Equity Method Investees
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	5	4
Other comprehensive income before reclassifications	0	0
Amounts reclassified from AOCI	0	0
Total other comprehensive loss, net of tax	0	0
Less other comprehensive income attributable to noncontrolling interests	0	0
Ending balance	5	4
Total
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	0	(92)
Other comprehensive income before reclassifications	(18)	(2)
Amounts reclassified from AOCI	4	0
Total other comprehensive loss, net of tax	(14)	(2)
Less other comprehensive income attributable to noncontrolling interests	6	(2)
Ending balance	(20)	(96)
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	12	2
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	$ 12	$ 2