Shareholders' Equity - Summary of Preferred Dividends Declared on Preferred Stock Issued (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
Class of Stock [Line Items]
Total preferred stock dividends declared	$ 228	$ 250	$ 452	$ 405
Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 290.72	$ 335.50	$ 602.28	$ 680.99
Total preferred stock dividends declared	$ 9	$ 11	$ 18	$ 21
Series C Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 290.72	$ 335.50	$ 602.28	$ 680.99
Total preferred stock dividends declared	$ 3	$ 3	$ 5	$ 6
Series D Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 285.72	$ 330.44	$ 592.17	$ 670.93
Total preferred stock dividends declared	$ 15	$ 18	$ 32	$ 36
Series E Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 1,187.17	$ 1,351.76	$ 2,405.93	$ 2,749.24
Total preferred stock dividends declared	$ 10	$ 10	$ 19	$ 21
Series F Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 1,187.8	$ 1,352.39	$ 2,407.19	$ 2,750.5
Total preferred stock dividends declared	$ 2	$ 2	$ 4	$ 4
Series O Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 662.50	$ 662.50	$ 662.50	$ 662.50
Total preferred stock dividends declared	$ 17	$ 17	$ 17	$ 17
Series T Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 475.00	$ 475.00	$ 475.00	$ 475.00
Total preferred stock dividends declared	$ 12	$ 13	$ 12	$ 13
Series Q Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)			$ 922.38	$ 922.38
Total preferred stock dividends declared			$ 17	$ 18
Series R Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)			$ 945.00	$ 618.75
Total preferred stock dividends declared			$ 21	$ 15
Series S Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)			$ 898.25	$ 550.00
Total preferred stock dividends declared			$ 12	$ 8
Series U Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)			$ 456.25	$ 456.25
Total preferred stock dividends declared			$ 14	$ 14
Series V Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 515.63	$ 515.63	$ 515.63	$ 515.63
Total preferred stock dividends declared	$ 15	$ 15	$ 15	$ 15
Series W Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)			$ 937.50	$ 937.50
Total preferred stock dividends declared			$ 56	$ 56
Series X Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 937.50	$ 937.50	$ 937.50	$ 937.50
Total preferred stock dividends declared	$ 84	$ 84	$ 84	$ 84
Series Y Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 765.63	$ 952.78	$ 765.63	$ 952.78
Total preferred stock dividends declared	$ 61	$ 77	$ 61	$ 77
Series Z Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)			$ 856.25	$ 0
Total preferred stock dividends declared			$ 65	$ 0