SECURITIES - Schedule of Investments in Continuous Loss Positions (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Fair Value
Less than 12 Months	$ 14,990
12 Months or Longer	1,236
Total	16,226
Gross Unrealized Losses
Less than 12 Months	(322)
12 Months or Longer	(55)
Total	(377)
Total mortgage-backed securities
Fair Value
Less than 12 Months	14,254
12 Months or Longer	1,236
Total	15,490
Gross Unrealized Losses
Less than 12 Months	(321)
12 Months or Longer	(55)
Total	(376)
Federal agencies and U.S. government sponsored entities
Fair Value
Less than 12 Months	14,131	$ 1,991
12 Months or Longer	1,236	0
Total	15,367	1,991
Gross Unrealized Losses
Less than 12 Months	(320)	(19)
12 Months or Longer	(55)	0
Total	(375)	$ (19)
Other/non-agency
Fair Value
Less than 12 Months	123
12 Months or Longer	0
Total	123
Gross Unrealized Losses
Less than 12 Months	(1)
12 Months or Longer	0
Total	(1)
Collateralized loan obligations, at fair value
Fair Value
Less than 12 Months	736
12 Months or Longer	0
Total	736
Gross Unrealized Losses
Less than 12 Months	(1)
12 Months or Longer	0
Total	$ (1)