Derivative Financial Instruments - Notional Amount of Interest Rate Swap Agreements Outstanding Maturity (Detail) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Total	$ 36,184	$ 26,977
Interest rate swap agreements
Derivative Instruments And Hedging Activities Disclosures [Line Items]
2025	10,384
2026	10,450
2027	6,000
2028	6,500
2029	0
Later years	2,850
Total	$ 36,184

Nominal or face amount used to calculate payment on derivative.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1B

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A

Name:	us-gaap_DerivativeNotionalAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant