Summary of Significant Accounting Policies Derivatives Pretax Amounts Affecting Income and Other Comprehensive Income (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (1)	$ (12)
Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in AOCI	(175)	164
Derivative, Excluded Component, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	(37)	0
Net Investment Hedging Relationships
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in AOCI	(1,793)	1,005
Derivative, Excluded Component, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	59	45
Interest rate \| Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in AOCI	(10)	38
Derivative, Excluded Component, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	2	1
Total Other Currencies \| Net Investment Hedging Relationships
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in AOCI	(1,599)	891
Derivative, Excluded Component, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]
Foreign currency
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(12)	(3)
Foreign currency \| Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in AOCI	(165)	126
Derivative, Excluded Component, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	(39)	(1)
Foreign currency derivatives \| Net Investment Hedging Relationships
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in AOCI	(194)	114
Cross Currency Interest Rate Contract [Member] \| Net Investment Hedging Relationships
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Excluded Component, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	59	45
Equity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 11	$ (9)