Shareholders' Equity - Summary of Preferred Dividends Declared on Preferred Stock Issued (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Class of Stock [Line Items]
Total preferred stock dividends declared	$ 107	$ 94	$ 356	$ 317
Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 239.58	$ 239.58	$ 710.93	$ 710.93
Total preferred stock dividends declared	$ 7	$ 7	$ 21	$ 21
Series C Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 255.56	$ 255.56	$ 758.34	$ 758.34
Total preferred stock dividends declared	$ 2	$ 2	$ 6	$ 6
Series D Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 255.56	$ 255.56	$ 758.34	$ 758.34
Total preferred stock dividends declared	$ 14	$ 14	$ 41	$ 41
Series E Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 1,022.22	$ 1,022.22	$ 3,044.44	$ 3,044.44
Total preferred stock dividends declared	$ 7	$ 8	$ 23	$ 23
Series F Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 1,022.22	$ 1,022.22	$ 3,044.44	$ 3,044.44
Total preferred stock dividends declared	$ 2	$ 2	$ 5	$ 5
Series J Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 343.75	$ 343.75	$ 1,031.25	$ 1,031.25
Total preferred stock dividends declared	$ 13	$ 14	$ 41	$ 41
Series K Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 398.44	$ 398.44	$ 1,195.32	$ 1,195.32
Total preferred stock dividends declared	$ 11	$ 11	$ 33	$ 33
Series N Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)			$ 0	$ 787.50
Total preferred stock dividends declared			$ 0	$ 19
Series O Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)			$ 662.50	$ 662.50
Total preferred stock dividends declared			$ 17	$ 17
Series P Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)			$ 625.00	$ 625.00
Total preferred stock dividends declared			$ 38	$ 38
Series Q Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 687.50	$ 687.50	$ 1,375	$ 1,375
Total preferred stock dividends declared	$ 14	$ 14	$ 28	$ 28
Series R Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 618.75	$ 618.75	$ 1,237.5	$ 1,237.5
Total preferred stock dividends declared	$ 15	$ 15	$ 30	$ 30
Series S Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 550.00	$ 550.00	$ 1,100	$ 1,100
Total preferred stock dividends declared	$ 8	$ 7	$ 16	$ 15
Series T Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)			$ 475.00	$ 0
Total preferred stock dividends declared			$ 13	$ 0
Series U Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 456.25	$ 0	$ 942.92	$ 0
Total preferred stock dividends declared	$ 14	$ 0	$ 28	$ 0
Series V Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)			$ 547.14	$ 0
Total preferred stock dividends declared			$ 16	$ 0