Consolidated Statements Of Cash Flows - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
OPERATING ACTIVITIES:
Net income		$ 49,603	$ 97,055
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses		57,953	12,463
Provision for depreciation and amortization		10,581	9,966
Amortization of investment security premiums, net		10,362	9,998
Investment securities (gains) losses, net	[1]	13,301	925
Net gains on sales of loans held for sale		(1,793)	(1,929)
Origination of loans held for sale		(33,351)	(46,454)
Proceeds from sales and repayments of held for sale		42,221	48,506
Net (increase) decrease in trading securities		(16,107)	4,632
Stock-based compensation		3,729	3,480
(Increase) decrease in interest receivable		(1,681)	(1,568)
Increase (decrease) in interest payable		(2,161)	2,708
Increase (decrease) in income taxes payable		7,992	20,479
Other changes, net		(60,881)	(18,080)
Net cash provided by (used in) operating activities		79,768	142,181
INVESTING ACTIVITIES:
Proceeds from sales of investment securities (A)	[1]	2	150,756
Proceeds from maturities/pay downs of investment securities (A)	[1]	641,950	252,824
Purchases of investment securities	[1]	(569,079)	(432,645)
Net (increase) decrease in loans		(346,910)	7,758
Purchases of land, buildings and equipment		(7,574)	(11,283)
Sales of land, buildings and equipment		17	1,268
Net cash provided by (used in) investing activities		(281,594)	(31,322)
FINANCING ACTIVITIES:
Net increase (decrease) in non-interest bearing, savings, interest checking and money market deposits		181,625	(620,589)
Net increase (decrease) in certificates of deposit		(233,664)	218,161
Net decrease in federal funds purchased and securities sold under agreements to repurchase		(422,759)	(233,638)
Repayment of long-term borrowings		0	(54)
Net increase (decrease) in short-term borrowings		754,043	(6,736)
Purchases of treasury stock		(53,145)	(39,699)
Issuance of stock under equity compensation plans		(26)	(4)
Cash dividends paid on common stock		(30,292)	(28,858)
Cash dividends paid on preferred stock		(2,250)	(2,250)
Net cash provided by (used in) financing activities		193,532	(713,667)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease)		(8,294)	(602,808)
Cash, cash equivalents and restricted cash at beginning of year		907,808	1,209,240
Cash, cash equivalents and restricted cash at March 31		899,514	606,432
Supplemental Cash Flow Information:
Income tax payments, net		1,170	1,350
Interest paid on deposits and borrowings		22,581	21,668
Loans transferred to foreclosed real estate		$ 57	$ 54

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