Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ (228,105)	$ 167,441
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	15,420	15,169
Provision for credit losses	553,691	26,131
(Gain) loss on other real estate and foreclosed assets	9,790	(1,093)
Gain on sale of securities	(112)
Deferred tax expense (benefit)	(48,786)	24,573
Increase in cash surrender value of life insurance contracts	(4,235)	(6,896)
(Gain) Loss on disposal of other assets	19	(81)
Net (increase) decrease in loans held for sale	(53,176)	(7,998)
Net amortization of securities premium/discount	19,208	14,628
Amortization of intangible assets	10,514	10,185
Stock-based compensation expense	11,086	10,368
Net change in liability from variation margin collateral	(113,616)	(18,918)
Contribution to pension plan		(100,000)
Decrease in interest payable and other liabilities	(4,493)	(1,907)
Increase in other assets	(86,813)	(183)
Other, net	(13,512)	(2,613)
Net cash provided by operating activities	66,880	128,806
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from the sale of available for sale securities	124,122
Proceeds from maturities of securities available for sale	385,125	125,154
Purchases of securities available for sale	(582,655)	(133,992)
Proceeds from maturities of securities held to maturity	124,037	191,553
Purchases of securities held to maturity	(12,359)	(154,498)
Net increase in short-term investments	(649,965)	(39,968)
Proceeds from sales of loans and leases	22,221	100,751
Net increase in loans	(2,029,351)	(278,834)
Purchase of life insurance contracts		(32,788)
Purchases of property and equipment	(19,607)	(22,718)
Proceeds from sale of property and equipment		202
Proceeds from sales of other real estate	7,678	6,134
Final cash settlement for acquisition of business		(1,112)
Other, net	(10,361)	(10,887)
Net cash used in investing activities	(2,641,115)	(251,003)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase in deposits	3,518,693	85,857
Net increase (decrease) in short-term borrowings	(959,997)	52,470
Proceeds from the issuance of long-term debt, net of issuance costs	166,812	11,649
Repayments of long-term debt	(153)	(151)
Dividends paid	(47,817)	(47,174)
Payroll tax remitted on net share settlement of equity awards	(1,585)	(845)
Proceeds from exercise of stock options		368
Proceeds from dividend reinvestment and stock purchase plans	2,018	1,803
Settlement of forward contract portion of accelerated share repurchase	12,110
Repurchase of shares	(12,716)
Net cash provided by financing activities	2,677,365	103,977
NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS	103,130	(18,220)
CASH AND DUE FROM BANKS, BEGINNING	432,104	383,372
CASH AND DUE FROM BANKS, ENDING	535,234	365,152
SUPPLEMENTAL INFORMATION FOR NON-CASH INVESTING AND FINANCING ACTIVITIES
Assets acquired in settlement of loans	$ 5,459	$ 6,070