Consolidated Statements Of Cash Flows - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
OPERATING ACTIVITIES:
Net income		$ 120,026	$ 133,229
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses		(9,858)	(6,232)
Provision for depreciation and amortization		11,811	11,379
Amortization of investment security premiums, net		4,932	22,079
Investment securities gains, net (A)	[1]	(7,163)	(9,853)
Net gains on sales of loans held for sale		(1,302)	(7,381)
Originations of loans held for sale		(57,580)	(172,435)
Proceeds from sales of loans held for sale		57,789	184,155
Net decrease in trading debt securities, excluding unsettled transactions		9,798	4,872
Stock-based compensation		4,218	3,933
(Increase) decrease in interest receivable		(7,972)	444
Increase (decrease) in interest payable		273	(1,804)
Increase in income taxes payable		28,657	28,105
Other changes, net		(29,115)	11,178
Net cash provided by operating activities		124,514	201,669
INVESTING ACTIVITIES:
Distributions received from equity-method investment		400	0
Proceeds from sales of investment securities (A)	[1]	1,745	9,292
Proceeds from maturities/pay downs of investment securities (A)	[1]	805,355	938,527
Purchases of investment securities (A)	[1]	(1,812,434)	(1,194,891)
Net increase in loans		(287,328)	(72,497)
Securities purchased under agreements to resell		(200,000)	0
Purchases of premises and equipment		(15,597)	(10,730)
Sales of premises and equipment		175	2,568
Net cash used in investing activities		(1,507,684)	(327,731)
FINANCING ACTIVITIES:
Net increase (decrease) in non-interest bearing, savings, interest checking and money market deposits		(208,358)	585,579
Net decrease in certificates of deposit		(303,277)	(73,000)
Net decrease in federal funds purchased and securities sold under agreements to repurchase		(705,506)	(160,273)
Net increase (decrease) in other borrowings		(3,503)	2,989
Purchases of treasury stock		(55,855)	(25,923)
Issuance of stock under equity compensation plans		448	(15)
Cash dividends paid on common stock		(32,143)	(30,799)
Net cash provided by (used in) financing activities		(1,308,194)	298,558
Increase (decrease) in cash, cash equivalents and restricted cash		(2,691,364)	172,496
Cash, cash equivalents and restricted cash at beginning of year		4,296,954	2,208,328
Cash, cash equivalents and restricted cash at March 31		1,605,590	2,380,824
Supplemental Cash Flow Information:
Income tax payments, net		1,640	2,510
Interest paid on deposits and borrowings		2,723	5,753
Loans transferred to foreclosed real estate		$ 25	$ 115

[1] Available for sale debt securities, equity securities, and other securities.