Consolidated Statements Of Cash Flows - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016
OPERATING ACTIVITIES:
Net income		$ 150,691	$ 135,330
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses		21,886	18,655
Provision for depreciation and amortization		19,890	20,689
Amortization of investment security premiums, net		17,827	16,014
Investment securities gains (losses), net	[1]	(879)	1,739
Net gains on sales of loans held for sale		(3,547)	(2,880)
Origination of loans held for sale		(96,943)	(70,880)
Proceeds from sales and repayments of held for sale		92,423	68,486
Net (increase) decrease in trading securities, excluding unsettled transactions		6,097	81,184
Stock-based compensation		6,195	6,287
(Increase) decrease in interest receivable		(428)	60
Increase (decrease) in interest payable		(692)	57
Increase (decrease) in income taxes payable		1,483	73
Other changes, net		(1,985)	(9,785)
Net cash provided by (used in) operating activities		212,018	265,029
INVESTING ACTIVITIES:
Proceeds from sales of investment securities	[1]	6,552	2,071
Proceeds from maturities/pay downs of investment securities	[1]	910,411	1,109,707
Purchases of investment securities	[1]	(625,931)	(414,154)
Net (increase) decrease in loans		(234,405)	(693,522)
Repayments of long-term securities purchased under agreements to resell		100,000	50,000
Purchases of land, buildings and equipment		(14,117)	(13,649)
Sales of land, buildings and equipment		2,527	5,399
Net cash provided by (used in) investing activities		145,037	45,852
FINANCING ACTIVITIES:
Net increase (decrease) in non-interest bearing, savings, interest checking and money market deposits		77,562	(38,985)
Net increase (decrease) in time open and C.D.'s		(157,367)	267,339
Net increase (decrease) in federal funds purchased and short-term securities sold under agreements to repurchase		(467,461)	(331,280)
Repayment of long-term borrowings		(146)	(840)
Additional long-term borrowings		0	900
Purchases of treasury stock		(10,628)	(37,462)
Issuance of stock under equity compensation plans		(7)	(2)
Cash dividends paid on common stock		(45,816)	(43,522)
Cash dividends paid on preferred stock		(4,500)	(4,500)
Net cash provided by (used in) financing activities		(608,363)	(188,352)
Increase (decrease) in cash and cash equivalents		(251,308)	122,529
Cash and cash equivalents at beginning of year		782,435	502,719
Cash and cash equivalents at end of period		531,127	625,248
Supplemental Cash Flow Information:
Income tax payments, net		54,621	59,886
Interest paid on deposits and borrowings		21,203	16,532
Loans transferred to foreclosed real estate		461	861
Transfer of loans held for investment to held for sale		$ 0	$ 50,360

[1] Available for sale and non-marketable securities