Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Operating Activities
Net Income	$ 189,535	$ 111,490
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Provision for Credit Losses	(40,800)	102,600
Depreciation and Amortization	15,751	14,929
Amortization of Deferred Loan and Lease (Fees) Costs, Net	(13,431)	(1,640)
Amortization and Accretion of Premiums/Discounts on Investment Securities, Net	27,147	19,043
Amortization of Operating Lease Right-of-Use Assets	8,562	9,192
Share-Based Compensation	9,658	5,347
Benefit Plan Contributions	(1,274)	(1,071)
Deferred Income Taxes	5,308	(31,725)
Gains on Sale of Premises and Equipment	(9,893)	(1,850)
Net Gains on Sales of Loans and Leases	(12,639)	(9,779)
Net Losses (Gains) on Sales of Investment Securities	39	(11,125)
Proceeds from Sales of Loans Held for Sale	412,153	333,770
Originations of Loans Held for Sale	(319,274)	(316,203)
Net Tax Benefits from Share-Based Compensation	1,349	469
Net Change in Other Assets and Other Liabilities	68,084	(135,753)
Net Cash Provided by Operating Activities	340,275	87,694
Investment Securities Available-for-Sale:
Proceeds from Sales, Prepayments and Maturities	1,138,809	733,619
Purchases	(1,789,229)	(1,238,926)
Investment Securities Held-to-Maturity:
Proceeds from Prepayments and Maturities	914,953	1,000,743
Purchases	(2,569,229)	(1,170,928)
Net Change in Loans and Leases	(149,765)	(782,613)
Purchases of Premises and Equipment	(14,314)	(25,693)
Proceeds from Sale of Premises and Equipment	9,008	1,981
Net Cash Used in Investing Activities	(2,459,767)	(1,481,817)
Financing Activities
Net Change in Deposits	2,282,057	1,954,401
Net Change in Short-Term Borrowings	(150,100)	(2,200)
Proceeds from Long-Term Debt		50,000
Repayments of Long-Term Debt	(50,067)	(75,063)
Net Proceeds from Issuance of Preferred Stock	175,487
Proceeds from Issuance of Common Stock	10,836	7,684
Repurchase of Common Stock	(23,412)	(17,897)
Cash Dividends Paid on Common Stock	(82,429)	(80,536)
Cash Dividends Paid on Preferred Stock	(1,006)
Net Cash Provided by Financing Activities	2,161,366	1,836,389
Net Change in Cash and Cash Equivalents	41,874	442,266
Cash and Cash Equivalents at Beginning of Period	614,088	558,658
Cash and Cash Equivalents at End of Period	655,962	1,000,924
Supplemental Information
Cash Paid for Interest	25,207	42,712
Cash Paid for Income Taxes	41,193	$ 46,949
Non-Cash Investing and Financing Activities:
Transfer from Loans to Loans Held for Sale	$ 23,888