Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating Activities
Net Income	$ 73,650	$ 115,718
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Provision for Credit Losses	74,000	7,000
Depreciation and Amortization	9,729	8,232
Amortization of Deferred Loan and Lease Fees	(586)	(487)
Amortization and Accretion of Premiums/Discounts on Investment Securities, Net	11,395	9,951
Amortization of Operating Lease Right-of-Use Assets	6,155	6,359
Share-Based Compensation	3,704	4,438
Benefit Plan Contributions	(718)	(887)
Deferred Income Taxes	(18,920)	(2,711)
Gains on Sale of Premises and Equipment	0	(558)
Net Gains on Sales of Loans and Leases	(5,398)	(2,166)
Net Losses (Gains) on Sales of Investment Securities	(12,246)	1,611
Proceeds from Sales of Loans Held for Sale	238,053	162,426
Originations of Loans Held for Sale	(239,735)	(173,117)
Net Tax Benefits from Share-Based Compensation	476	637
Net Change in Other Assets and Other Liabilities	(103,794)	(36,486)
Net Cash Provided by Operating Activities	35,765	99,960
Investment Securities Available-for-Sale:
Proceeds from Sales, Prepayments and Maturities	477,253	1,423,672
Purchases	(509,271)	(1,029,942)
Investment Securities Held-to-Maturity:
Proceeds from Prepayments and Maturities	576,930	367,211
Purchases	(819,130)	(864,955)
Net Change in Loans and Leases	(801,879)	(316,228)
Purchases of Premises and Equipment	19,923	26,146
Proceeds from Sale of Premises and Equipment	0	639
Net Cash Used in Investing Activities	(1,096,020)	(445,749)
Financing Activities
Net Change in Deposits	1,638,673	461,579
Net Change in Short-Term Borrowings	(1,100)	(196)
Proceeds from Long-Term Debt	50,000	0
Repayments of Long-Term Debt	(75,041)	(25,038)
Proceeds from Issuance of Common Stock	6,115	4,214
Repurchase of Common Stock	(17,781)	(78,175)
Cash Dividends Paid	(53,679)	(52,201)
Net Cash Provided by Financing Activities	1,547,187	310,183
Net Change in Cash and Cash Equivalents	486,932	(35,606)
Cash and Cash Equivalents at Beginning of Period	558,658	525,969
Cash and Cash Equivalents at End of Period	1,045,590	490,363
Supplemental Information
Cash Paid for Interest	31,700	44,077
Cash Paid for Income Taxes	6,895	29,868
Non-Cash Investing and Financing Activities:
Initial Recognition of Operating Lease Right-of-Use Assets	97,166	106,514
Initial Recognition of Operating Lease Liabilities	104,741	113,394
Transfer from Investment Securities Held-To-Maturity to Investment Securities Available-For-Sale	0	1,014,859
Transfer from Loans to Foreclosed Real Estate	$ 0	$ 1,869