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Share Repurchase Program (Details) - USD ($) $ / shares in Units, $ in Millions | 1 Months Ended | 3 Months Ended | 10 Months Ended | 171 Months Ended |
--- | --- | --- | --- | --- | ---
Apr. 21, 2021 | Mar. 31, 2021 | Sep. 30, 2020 | Mar. 31, 2020 | Dec. 31, 2020 | Mar. 31, 2021 | Apr. 01, 2019
Shares Repurchased [Line Items] |  |  |  |  |  |  |  |
BOD authorized |  |  |  |  |  |  |  | 150,000,000
Stock repurchase program expiration date |  |  | Mar. 31, 2022 |  |  |  |  |
Aggregate cost |  |  | $ 1,402 |  | $ 2,956 |  | $ 42,300 |
Shares repurchased | [1] |  | 6,691,421 |  | 14,305,793 |  |  |
Average purchase price | [1],[2] |  | $ 209.50 |  | $ 178.66 |  |  |
Remaining number of shares that may be repurchased under current authority |  |  | 104,331,549 |  |  |  | 104,331,549 |
Treasury stock, value |  |  | $ 41,826 |  |  | $ 40,420 | $ 41,826 |
Accelerated Share Repurchase Agreement [Member] |  |  |  |  |  |  |  |
Shares Repurchased [Line Items] |  |  |  |  |  |  |  |
Aggregate cost |  |  |  |  |  | $ 2,000 |  |
Shares repurchased |  |  |  | 4,045,575 | 8,786,380 | 8,786,380 |  |
Average purchase price |  |  |  |  | $ 155.86 |  |  |
Subsequent Event [Member] |  |  |  |  |  |  |  |
Shares Repurchased [Line Items] |  |  |  |  |  |  |  |
Aggregate cost |  | $ 237 |  |  |  |  |  |
Shares repurchased |  | 1,100,000 |  |  |  |  |  |
[1] | Includes 8,786,380 shares repurchased in February 2020 under accelerated share repurchase programs.
[2] | In the period of the final settlement, the average price paid under the accelerated share repurchase programs is calculated based on the total program value less the value assigned to the initial delivery of shares. The average price of the completed 2020 accelerated share repurchase programs was $155.86.

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