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Capital Stock - Summary of Normal Course Issuer Bids (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021
Schedule Of Share Repurchase Programs [Line Items] |  |
Shares purchased | 12,561,487 | 5,992,323
Cash amount | $ 780 | $ 517
2020 Bid [Member] |  |
Schedule Of Share Repurchase Programs [Line Items] |  |
Shares purchased | 0 | 3,318,523
Cash amount | $ 0 | $ 301
2021 Bid [Member] |  |
Schedule Of Share Repurchase Programs [Line Items] |  |
Shares purchased | 0 | 2,673,800
Cash amount | $ 0 | $ 216
2022 Bid [Member] |  |
Schedule Of Share Repurchase Programs [Line Items] |  |
Shares purchased | 12,561,487 | 0
Cash amount | $ 780 | $ 0

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