INVESTMENTS - Fair Value of AFS Debt Securities by Contractual Maturity Date (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Available for Sale Securities, Debt Maturities, Amortized Cost
Total amortized cost	$ 229,075
Available for Sale Securities, Debt Maturities, Fair Value
Total fair value	$ 226,876	$ 256,936
Available for Sale Securities, Debt Maturities, Weighted Average Yield
Total	4.22%
Unallocated portfolio layer cumulative basis adjustments	$ (72)
Mortgage-backed securities
Available for Sale Securities, Debt Maturities, Amortized Cost
Due within 1 year, amortized cost	19
After 1 but within 5 years, amortized cost	880
After 5 but within 10 years, amortized cost	556
After 10 years, amortized cost	29,573
Total amortized cost	31,028
Available for Sale Securities, Debt Maturities, Fair Value
Due within 1 year, fair value	19
After 1 but within 5 years, fair value	869
After 5 but within 10 years, fair value	526
After 10 Years, fair value	28,517
Total fair value	$ 29,931	30,139
Available for Sale Securities, Debt Maturities, Weighted Average Yield
Due within 1 year, weighted average yield	2.60%
After 1 but within 5 years, weighted average yield	4.05%
After 5 but within 10 years, weighted average yield	3.95%
After 10 Years, weighted average yield	4.58%
Total	4.55%
U.S. Treasury and federal agency securities
Available for Sale Securities, Debt Maturities, Amortized Cost
Due within 1 year, amortized cost	$ 30,956
After 1 but within 5 years, amortized cost	21,474
After 5 but within 10 years, amortized cost	200
After 10 years, amortized cost	0
Total amortized cost	52,630
Available for Sale Securities, Debt Maturities, Fair Value
Due within 1 year, fair value	30,924
After 1 but within 5 years, fair value	21,280
After 5 but within 10 years, fair value	175
After 10 Years, fair value	0
Total fair value	$ 52,379	80,361
Available for Sale Securities, Debt Maturities, Weighted Average Yield
Due within 1 year, weighted average yield	1.91%
After 1 but within 5 years, weighted average yield	3.14%
After 5 but within 10 years, weighted average yield	3.63%
After 10 Years, weighted average yield	0.00%
Total	2.42%
State and municipal
Available for Sale Securities, Debt Maturities, Amortized Cost
Due within 1 year, amortized cost	$ 12
After 1 but within 5 years, amortized cost	131
After 5 but within 10 years, amortized cost	399
After 10 years, amortized cost	1,207
Total amortized cost	1,749
Available for Sale Securities, Debt Maturities, Fair Value
Due within 1 year, fair value	12
After 1 but within 5 years, fair value	126
After 5 but within 10 years, fair value	387
After 10 Years, fair value	1,133
Total fair value	$ 1,658	2,131
Available for Sale Securities, Debt Maturities, Weighted Average Yield
Due within 1 year, weighted average yield	1.75%
After 1 but within 5 years, weighted average yield	3.68%
After 5 but within 10 years, weighted average yield	3.70%
After 10 Years, weighted average yield	3.99%
Total	3.89%
Foreign government
Available for Sale Securities, Debt Maturities, Amortized Cost
Due within 1 year, amortized cost	$ 58,930
After 1 but within 5 years, amortized cost	69,775
After 5 but within 10 years, amortized cost	4,770
After 10 years, amortized cost	527
Total amortized cost	134,002
Available for Sale Securities, Debt Maturities, Fair Value
Due within 1 year, fair value	58,958
After 1 but within 5 years, fair value	69,297
After 5 but within 10 years, fair value	4,670
After 10 Years, fair value	434
Total fair value	$ 133,359	131,198
Available for Sale Securities, Debt Maturities, Weighted Average Yield
Due within 1 year, weighted average yield	4.73%
After 1 but within 5 years, weighted average yield	5.17%
After 5 but within 10 years, weighted average yield	4.50%
After 10 Years, weighted average yield	4.85%
Total	4.95%
All other
Available for Sale Securities, Debt Maturities, Amortized Cost
Due within 1 year, amortized cost	$ 5,122
After 1 but within 5 years, amortized cost	3,731
After 5 but within 10 years, amortized cost	741
After 10 years, amortized cost	72
Total amortized cost	9,666
Available for Sale Securities, Debt Maturities, Fair Value
Due within 1 year, fair value	5,110
After 1 but within 5 years, fair value	3,657
After 5 but within 10 years, fair value	743
After 10 Years, fair value	39
Total fair value	$ 9,549
Available for Sale Securities, Debt Maturities, Weighted Average Yield
Due within 1 year, weighted average yield	2.55%
After 1 but within 5 years, weighted average yield	3.31%
After 5 but within 10 years, weighted average yield	2.18%
After 10 Years, weighted average yield	1.84%
Total	2.81%
Debt securities
Available for Sale Securities, Debt Maturities, Fair Value
Total fair value	$ 226,876	$ 256,936
Available for Sale Securities, Debt Maturities, Weighted Average Yield
Unallocated portfolio layer cumulative basis adjustments	$ (200)

Debt Securities, Available for sale, Amortized Cost, after Allowance for Credit Loss, Maturity

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Debt Securities, Available for Sale, Amortized Cost, Excluding Accrued Interest, Before Allowance for Credit Loss, Excluding Unallocated Portfolio Layer Adjustments

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Weighted average yield of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk, in portfolio layer hedging relationship.

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