Discontinued Operations (Consolidated Income Statement - Discontinued Operations) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from discontinued operations before taxes		$ 251	$ 5,777	$ 700
Income taxes from discontinued operations		40	1,222	111
Net income from discontinued operations		211	4,555	589
BlackRock, Inc. \| Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noninterest income		251	5,777	700
Total revenue		251	5,777	700
Income from discontinued operations before taxes		251	5,777	700
Income taxes from discontinued operations		40	1,222	111
Net income from discontinued operations	$ 0	$ 211	$ 4,555	$ 589

Amount before tax of income (loss) from a discontinued operation. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

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