Earnings Per Common Share - Computations of Basic Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income available to common shareholders:
Net income	$ 1,858,746	$ 1,353,152	$ 1,929,149
Less: Preferred stock dividends	(72,915)	(68,228)	(69,441)
Net income available to common equity	1,785,831	1,284,924	1,859,708
Less: Income attributable to unvested stock-based compensation awards	(8,854)	(5,858)	(10,199)
Net income available to common shareholders	$ 1,776,977	$ 1,279,066	$ 1,849,509
Weighted-average shares outstanding:
Common shares outstanding (including common stock issuable) and unvested stock-based compensation awards	129,539	129,404	135,169
Less: Unvested stock-based compensation awards	(890)	(766)	(741)
Weighted-average shares outstanding	128,649	128,638	134,428
Basic earnings per common share	$ 13.81	$ 9.94	$ 13.76