INVESTMENTS - Investment Exposures Individually Exceeded 10% of Shareholders' Equity (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023
Investments [Abstract]
Credit Rating	[1]	A+	A+
Amortized Cost	[1]	$ 33,822	$ 39,151
Fair Value	[1]	$ 32,844	$ 40,222
Investment, Type [Extensible Enumeration]		Japan National Government [Member]	Japan National Government [Member]

[1] Japan Government Bonds (JGBs) or JGB-backed securities