Investment Securities - Securities in Gross Unrealized Loss Position (Details) $ in Millions	Jun. 30, 2022 USD ($) security	Dec. 31, 2021 USD ($) security
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	$ 56,366	$ 41,701
Fair Value - 12 Months or Longer	17,439	9,410
Fair Value - Total	73,805	51,111
Gross Unrealized Loss - Less than 12 Months	(4,402)	(670)
Gross Unrealized Loss - 12 Months or Longer	(2,751)	(326)
Gross Unrealized Loss - Total	$ (7,153)	$ (996)
Number of securities in gross unrealized loss positions \| security	2,500	740
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	$ 4,098
Fair Value - 12 Months or Longer	0
Fair Value - Total	4,098
Gross Unrealized Loss - Less than 12 Months	(44)
Gross Unrealized Loss - 12 Months or Longer	0
Gross Unrealized Loss - Total	(44)
RMBS, Agency
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	45,363	$ 37,492
Fair Value - 12 Months or Longer	16,238	8,606
Fair Value - Total	61,601	46,098
Gross Unrealized Loss - Less than 12 Months	(4,001)	(632)
Gross Unrealized Loss - 12 Months or Longer	(2,602)	(299)
Gross Unrealized Loss - Total	(6,603)	(931)
RMBS, Non-agency
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	19	3
Fair Value - 12 Months or Longer	0	1
Fair Value - Total	19	4
Gross Unrealized Loss - Less than 12 Months	(1)	0
Gross Unrealized Loss - 12 Months or Longer	0	0
Gross Unrealized Loss - Total	(1)	0
RMBS
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	45,382	37,495
Fair Value - 12 Months or Longer	16,238	8,607
Fair Value - Total	61,620	46,102
Gross Unrealized Loss - Less than 12 Months	(4,002)	(632)
Gross Unrealized Loss - 12 Months or Longer	(2,602)	(299)
Gross Unrealized Loss - Total	(6,604)	(931)
CMBS, Agency
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	5,929	2,999
Fair Value - 12 Months or Longer	1,201	803
Fair Value - Total	7,130	3,802
Gross Unrealized Loss - Less than 12 Months	(345)	(36)
Gross Unrealized Loss - 12 Months or Longer	(149)	(27)
Gross Unrealized Loss - Total	(494)	(63)
Other securities
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	957	1,207
Fair Value - 12 Months or Longer	0	0
Fair Value - Total	957	1,207
Gross Unrealized Loss - Less than 12 Months	(11)	(2)
Gross Unrealized Loss - 12 Months or Longer	0	0
Gross Unrealized Loss - Total	$ (11)	$ (2)

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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