Discontinued Operations (Consolidated Income Statement - Discontinued Operations) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from discontinued operations before taxes	$ 5,596	$ 224	$ 5,777	$ 449
Income taxes from discontinued operations	1,197	35	1,222	71
Net income from discontinued operations	4,399	189	4,555	378
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	5,596	224	5,777	449
Total revenue	5,596	224	5,777	449
Income from discontinued operations before taxes	5,596	224	5,777	449
Income taxes from discontinued operations		35		71
Net income from discontinued operations	$ 4,399	$ 189	$ 4,555	$ 378

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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