Income Taxes - Rollforward of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Rollforward of Unrecognized Tax Benefits
Balance at beginning of period	$ 755	$ 755	$ 1,080
Increase based on tax positions related to the current period	201	139	57
Increase based on tax positions related to prior periods	74	178	61
Increase based on the acquisition of E*TRADE	0	26	0
Decrease based on tax positions related to prior periods	(37)	(297)	(419)
Decreases related to settlements with taxing authorities	(10)	(36)	(17)
Decreases related to lapse of statute of limitations	(12)	(10)	(7)
Balance at end of period	971	755	755
Net unrecognized tax benefits	$ 860	$ 665	$ 549

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of unrecognized tax benefits.

+ References

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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Amount of increase in unrecognized tax benefits resulting from acquisitions.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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