Shareholders' Equity - Summary of Preferred Dividends Declared on Preferred Stock Issued (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Class of Stock [Line Items]
Total preferred stock dividends declared	$ 224	$ 155
Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 311.56	$ 345.49
Total preferred stock dividends declared	$ 9	$ 10
Series C Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 311.56	$ 345.49
Total preferred stock dividends declared	$ 2	$ 3
Series D Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 306.45	$ 340.49
Total preferred stock dividends declared	$ 17	$ 18
Series E Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 1,218.76	$ 1,397.48
Total preferred stock dividends declared	$ 9	$ 11
Series F Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 1,219.39	$ 1,398.11
Total preferred stock dividends declared	$ 2	$ 2
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 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 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