Consolidated Statements Of Cash Flows - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
OPERATING ACTIVITIES:
Net income		$ 102,061	$ 71,702
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses		10,396	11,128
Provision for depreciation and amortization		9,620	10,019
Amortization of investment security premiums, net		7,233	9,231
Investment securities gains (losses), net	[1]	(5,410)	772
Net gains on sales of loans held for sale		(1,147)	(866)
Origination of loans held for sale		(44,066)	(34,716)
Proceeds from sales and repayments of held for sale		49,255	34,446
Net (increase) decrease in trading securities, excluding unsettled transactions		(18,543)	7,763
Stock-based compensation		3,290	3,135
(Increase) decrease in interest receivable		744	(686)
Increase (decrease) in interest payable		(732)	39
Increase (decrease) in income taxes payable		22,076	21,156
Other changes, net		9,212	5,152
Net cash provided by (used in) operating activities		143,989	138,275
INVESTING ACTIVITIES:
Proceeds from sales of investment securities	[1]	148,652	98
Proceeds from maturities/pay downs of investment securities	[1]	358,690	483,090
Purchases of investment securities	[1]	(298,554)	(482,642)
Net (increase) decrease in loans		78,838	(169,185)
Purchases of land, buildings and equipment		(4,982)	(5,456)
Sales of land, buildings and equipment		718	717
Net cash provided by (used in) investing activities		283,362	(173,378)
FINANCING ACTIVITIES:
Net increase (decrease) in non-interest bearing, savings, interest checking and money market deposits		54,986	49,469
Net increase (decrease) in time open and C.D.'s		(9,961)	174,052
Net increase (decrease) in federal funds purchased and short-term securities sold under agreements to repurchase		(374,809)	(402,756)
Repayment of long-term borrowings		(74)	(74)
Proceeds from Short-term Debt		7,530	0
Purchases of treasury stock		(17,067)	(7,284)
Issuance of stock under equity compensation plans		(6)	(6)
Cash dividends paid on common stock		(25,106)	(22,913)
Cash dividends paid on preferred stock		(2,250)	(2,250)
Net cash provided by (used in) financing activities		(366,757)	(211,762)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect		60,594	(246,865)
Cash, cash equivalents and restricted cash at beginning of year		524,352	801,641
Cash, cash equivalents and restricted cash at March 31		584,946	554,776
Supplemental Cash Flow Information:
Income tax payments, net		147	2,850
Interest paid on deposits and borrowings		13,835	9,685
Loans transferred to foreclosed real estate		$ 1,028	$ 134

[1] Available for sale and non-marketable securities