Consolidated Statement of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	ASU 2016-13 [Member]	Series A And Series C [Member]	Series G Preferred Stock [Member]	Series I Preferred Stock [Member]	Preferred Stock [Member]	Preferred Stock [Member] Series A And Series C [Member]	Preferred Stock [Member] Series G Preferred Stock [Member]	Preferred Stock [Member] Series I Preferred Stock [Member]	Common Stock [Member]	Common Stock Issuable [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Series G Preferred Stock [Member]	Additional Paid-in Capital [Member] Series I Preferred Stock [Member]	Retained Earnings [Member]	Retained Earnings [Member] ASU 2016-13 [Member]	Accumulated Other Comprehensive Income (Loss), Net [Member]	Treasury Stock [Member]
Beginning balance at Dec. 31, 2018	$ 15,460,191					$ 1,231,500				$ 79,883	$ 1,726	$ 6,579,342			$ 11,516,672		$ (420,081)	$ (3,528,851)
Total comprehensive income	2,142,550														1,929,149		213,401
Preferred stock cash dividends	(72,482)														(72,482)
Redemption of Series A and Series C preferred stock			$ (381,500)				$ (381,500)
Issuance of preferred stock				$ 396,000				$ 400,000					$ (4,000)
Purchases of treasury stock	(1,349,785)																	(1,349,785)
Stock-based compensation transactions, net	73,891									(12)	(160)	18,197			(207)			56,073
Common stock cash dividends	(552,216)														(552,216)
Ending balance at Dec. 31, 2019	15,716,649					1,250,000				79,871	1,566	6,593,539			12,820,916		(206,680)	(4,822,563)
Cumulative effect of change in accounting principle — credit losses		$ (91,925)														$ (91,925)
Total comprehensive income	1,496,800														1,353,152		143,648
Preferred stock cash dividends	(68,228)														(68,228)
Purchases of treasury stock	(373,750)																	(373,750)
Stock-based compensation transactions, net	76,813										(222)	23,865			(411)			53,581
Common stock cash dividends	(569,076)														(569,076)
Ending balance at Dec. 31, 2020	16,187,283					1,250,000				79,871	1,344	6,617,404			13,444,428		(63,032)	(5,142,732)
Total comprehensive income	1,794,200														1,858,746		(64,546)
Preferred stock cash dividends	(72,915)														(72,915)
Issuance of preferred stock					$ 495,000				$ 500,000					$ (5,000)
Stock-based compensation transactions, net	82,804										(132)	22,596			(844)			61,184
Common stock cash dividends	(582,967)														(582,967)
Ending balance at Dec. 31, 2021	$ 17,903,405					$ 1,750,000				$ 79,871	$ 1,212	$ 6,635,000			$ 14,646,448		$ (127,578)	$ (5,081,548)