Consolidated Statement of Cash Flows (Statement) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Net Income (Loss) Attributable to Parent	$ 153,945	$ 127,923	$ 102,700
(Recovery of) provision for credit losses	(11,916)	12,054	6,171
Amortization of Deferred Loan Origination Fees, Net	(25,185)	(21,598)	(6,826)
Goodwill, Purchase Accounting Adjustments	(1,519)	(2,403)	(3,373)
Depreciation	13,267	10,814	9,119
Accretion (Amortization) of Discounts and Premiums, Investments	2,174	1,362	1,455
Payment for Debt Extinguishment or Debt Prepayment Cost	0	10,529	612
Deferred Income Tax Expense (Benefit)	(3,131)	(4,525)	(844)
Gain (Loss) on Sale of Investments	0	3,286	(421)
Gain on equity securities, net	5,011	2,182	5,118
Share-based Payment Arrangement, Noncash Expense	8,021	7,272	6,324
Payments for Loan Originations, Loans to be Sold in Secondary Market	569,080	1,026,346	338,437
Proceeds From Loan Sales	609,377	1,031,227	340,637
Gains (Losses) on Sales of Other Real Estate	(4)	1,207	(222)
Bank Owned Life Insurance Income	4,897	4,789	4,557
Amortization Method Qualified Affordable Housing Project Investments, Amortization	7,313	7,046	6,927
Increase (Decrease) in Other Operating Assets and Liabilities, Net [Abstract]
Increase (Decrease) in Other Operating Assets	(12,342)	(9,216)	(12,530)
Increase (Decrease) in Other Operating Liabilities	(7,939)	(6,302)	(3,781)
Net cash provided by operating activities	157,332	111,646	111,626
Net Cash Provided by (Used in) Investing Activities [Abstract]
Payments for (Proceeds from) Federal Home Loan Bank Stock	(8,677)	(7,970)	(14,675)
Proceeds from Sale of Debt Securities	934	312,160	91,110
Proceeds from Sale, Maturity and Collection of Investments [Abstract]
Proceeds from Sale and Maturity of Held-to-maturity Securities	0	0	475
Proceeds from Sale and Maturity of Debt Securities, Available-for-sale	232,197	223,728	195,989
Payments to Acquire Investments [Abstract]
Payments to Acquire Debt Securities, Available-for-sale	953,900	354,299	0
Payments to Acquire Available-for-sale Securities, Equity	0	3,567	100
Payments for (Proceeds from) Federal Reserve Bank Stock	0	0	(6,428)
Increase (Decrease) in Equity Securities, FV-NI	(2,597)	(2,120)	(6,429)
Payments for (Proceeds from) Loans and Leases	(312,187)	620,200	216,353
Proceeds from Sale of Other Loans Held-for-sale	3,718	4,400	0
Proceeds from Sale of Other Real Estate	758	5,654	1,465
Proceeds from Life Insurance Policy	5,598	1,360	1,571
Payment to Acquire Life Insurance Policy, Investing Activities	0	0	(3,000)
Payments for Affordable Housing Programs	10,814	6,596	6,038
Payments to Acquire Property, Plant, and Equipment	14,093	28,632	14,885
Payments to Acquire Businesses, Net of Cash Acquired	0	0	4,831
Net cash used in investing activities	(412,141)	(455,902)	60,079
Net Cash Provided by (Used in) Financing Activities [Abstract]
Increase (Decrease) in Deposits	605,168	1,230,073	159,696
(Increase) decrease in one way sell deposits	(272,952)	(710,101)	0
Proceeds from (Repayments of) Short-term Debt	(103,444)	111,573	(20,072)
Proceeds from Issuance of Long-term Debt	0	0	50,000
Proceeds from Issuance of Subordinated Long-term Debt	0	172,620	0
Repayments of Long-term Debt	32,500	170,529	258,112
Payments Related to Tax Withholding for Share-based Compensation	2,403	1,002	827
Payments for Repurchase of Common Stock	16,048	7,507	40,535
Payments of Ordinary Dividends	74,306	70,353	69,113
Net cash provided by (used in) financing activities	103,515	554,774	(178,963)
Cash and Cash Equivalents, Period Increase (Decrease), Total	(151,294)	210,518	(7,258)
Cash and Cash Equivalents, at Carrying Value, Beginning Balance	370,474	159,956	167,214
Cash and Cash Equivalents, at Carrying Value, Ending Balance	219,180	370,474	159,956
Supplemental Cash Flow Information [Abstract]
Interest Paid, Excluding Capitalized Interest, Operating Activities	16,704	29,157	63,038
Income Taxes Paid	25,505	24,260	15,186
Noncash Investing and Financing Items [Abstract]
Debt Securities, Held-to-maturity, Transfer, Amount	0	0	349,773
Real Estate Owned, Transfer to Real Estate Owned	150	1,790	1,671
Other Significant Noncash Transaction, Value of Consideration Received	1,190	7,821	11,475
Affordable Housing Program Obligation, Period Increase (Decrease)	10,000	10,000	10,000
Transfer to Investments	3,000	0
Mortgages [Member]
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Gain (Loss) on Sale of Loans and Leases	18,018	24,269	7,198
Consumer Portfolio Segment [Member]
Increase (Decrease) in Other Operating Assets and Liabilities, Net [Abstract]
Increase (Decrease) in Prepaid Expense	$ (2,415)	$ (8,890)	$ (5,358)