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Commitments, Contingencies and Off-Balance Sheet Arrangements - Off-Balance Sheet Commitments (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2026 USD ($)
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Amount of Commitment Expiration by Period - 2026	$ 0
Amount of Commitment Expiration by Period - 2027	0
Amount of Commitment Expiration by Period - 2028	0
Amount of Commitment Expiration by Period - 2029	0
Amount of Commitment Expiration by Period - 2030	0
Amount of Commitment Expiration by Period - Thereafter	63
Total Amounts Committed	63
Financial guarantees
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Amount of Commitment Expiration by Period - 2026	0
Amount of Commitment Expiration by Period - 2027	0
Amount of Commitment Expiration by Period - 2028	0
Amount of Commitment Expiration by Period - 2029	0
Amount of Commitment Expiration by Period - 2030	0
Amount of Commitment Expiration by Period - Thereafter	49
Total Amounts Committed	49
Letters of credit
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Amount of Commitment Expiration by Period - 2026	0
Amount of Commitment Expiration by Period - 2027	0
Amount of Commitment Expiration by Period - 2028	0
Amount of Commitment Expiration by Period - 2029	0
Amount of Commitment Expiration by Period - 2030	0
Amount of Commitment Expiration by Period - Thereafter	14
Total Amounts Committed	$ 14

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