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Restructuring - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2021
Restructuring Cost and Reserve [Line Items]
Expected restructuring and related cost	$ 3,000		$ 3,000
Estimate of cumulative pre tax costs that will result in cash outlays			70.00%
Estimate of cumulative pre tax costs that will be noncash			30.00%
Total pretax restructuring costs	168	$ 185	$ 630	$ 500
Cumulative costs since program inception	$ 2,400		$ 2,400
Forecast
Restructuring Cost and Reserve [Line Items]
Expected restructuring and related cost					$ 700

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Estimate of cumulative pre tax costs that will result in cash outlays (primarily from employee separation expense).

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Amount of costs incurred to date for the specified restructuring cost.

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Amount expected to be recognized in earnings for the specified restructuring cost.

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