Earnings Per Common Share - Computations of Diluted 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
Earnings Per Share [Abstract]
Net income available to common equity	$ 1,785,831	$ 1,284,924	$ 1,859,708
Less: Income attributable to unvested stock-based compensation awards	(8,844)	(5,856)	(10,197)
Net income available to common shareholders	$ 1,776,987	$ 1,279,068	$ 1,849,511
Adjusted weighted-average shares outstanding:
Common and unvested stock-based compensation awards	129,539	129,404	135,169
Less: Unvested stock-based compensation awards	(890)	(766)	(741)
Plus: Incremental shares from assumed conversion of stock-based compensation awards and warrants to purchase common stock	163	66	34
Adjusted weighted-average shares outstanding	128,812	128,704	134,462
Diluted earnings per common share	$ 13.80	$ 9.94	$ 13.75