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v3.26.1

Shareholders' equity - Issued and Outstanding Preferred Stock (Detail) - USD ($) $ / shares in Units, $ in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2026 | Jun. 30, 2025 | Jun. 30, 2026 | Jun. 30, 2025 | Dec. 31, 2025
Class of Stock [Line Items] |  |  |  |  |
Preferred stock, shares issued (in shares) | 10,220,000 |  | 10,220,000 |  | 10,260,000
Preferred stock, shares outstanding (in shares) | 10,220,000 |  | 10,220,000 |  | 10,260,000
Carrying Amount | $ 2,434 |  | $ 2,434 |  | $ 2,834
Preferred Series F |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |
Preferred stock, shares issued (in shares) | 50,000 |  | 50,000 |  | 50,000
Preferred stock, shares outstanding (in shares) | 50,000 |  | 50,000 |  | 50,000
Preferred stock, liquidation preference per share (in USD per share) | $ 10,000 |  | $ 10,000 |  |
Preferred stock dividend rate (as a percent) |  |  | 5.125% |  |
Carrying Amount | $ 500 |  | $ 500 |  | $ 500
Preferred stock per share dividend amount (in USD per share) | $ 128.13 | $ 128.13 | $ 256.25 | $ 256.25 |
Preferred stock. dividend rate spread (as a percent) |  |  | 3.78% |  |
Preferred Series G |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |
Preferred stock, shares issued (in shares) | 0 |  | 0 |  | 40,000
Preferred stock, shares outstanding (in shares) | 0 |  | 0 |  | 40,000
Preferred stock, liquidation preference per share (in USD per share) | $ 10,000 |  | $ 10,000 |  |
Preferred stock dividend rate (as a percent) |  |  | 0.00% |  |
Carrying Amount | $ 0 |  | $ 0 |  | $ 400
Preferred stock per share dividend amount (in USD per share) | $ 0 | 182.60 | $ 182.60 | 365.20 |
Preferred Series H |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |
Preferred stock, shares issued (in shares) | 10,000,000 |  | 10,000,000 |  | 10,000,000
Preferred stock, shares outstanding (in shares) | 10,000,000 |  | 10,000,000 |  | 10,000,000
Preferred stock, liquidation preference per share (in USD per share) | $ 25 |  | $ 25 |  |
Preferred stock dividend rate (as a percent) |  |  | 5.625% |  |
Carrying Amount | $ 261 |  | $ 261 |  | $ 261
Preferred stock per share dividend amount (in USD per share) | $ 0.35 | 0.35 | $ 0.70 | 0.70 |
Preferred stock. dividend rate spread (as a percent) |  |  | 4.28% |  |
Preferred Series I |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |
Preferred stock, shares issued (in shares) | 50,000 |  | 50,000 |  | 50,000
Preferred stock, shares outstanding (in shares) | 50,000 |  | 50,000 |  | 50,000
Preferred stock, liquidation preference per share (in USD per share) | $ 10,000 |  | $ 10,000 |  |
Preferred stock dividend rate (as a percent) |  |  | 3.50% |  |
Carrying Amount | $ 500 |  | $ 500 |  | $ 500
Preferred stock per share dividend amount (in USD per share) | $ 87.50 | 87.50 | $ 175.00 | 175.00 |
Preferred stock. dividend rate spread (as a percent) |  |  | 2.679% |  |
Preferred Series J |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |
Preferred stock, shares issued (in shares) | 75,000 |  | 75,000 |  | 75,000
Preferred stock, shares outstanding (in shares) | 75,000 |  | 75,000 |  | 75,000
Preferred stock, liquidation preference per share (in USD per share) | $ 10,000 |  | $ 10,000 |  |
Preferred stock dividend rate (as a percent) |  |  | 7.50% |  |
Carrying Amount | $ 733 |  | $ 733 |  | $ 733
Preferred stock per share dividend amount (in USD per share) | $ 187.50 | 187.50 | $ 375.00 | 375.00 |
Preferred Series K |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |
Preferred stock, shares issued (in shares) | 45,000 |  | 45,000 |  | 45,000
Preferred stock, shares outstanding (in shares) | 45,000 |  | 45,000 |  | 45,000
Preferred stock, liquidation preference per share (in USD per share) | $ 10,000 |  | $ 10,000 |  |
Preferred stock dividend rate (as a percent) |  |  | 6.35% |  |
Carrying Amount | $ 440 |  | $ 440 |  | $ 440
Preferred stock per share dividend amount (in USD per share) | $ 158.75 | $ 0 | $ 317.50 | $ 0 |

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