Fair Value (Fair Value Of Financial Instruments) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and money market instruments	$ 943,275,000	$ 370,474,000
Investment securities	1,115,284,000	1,059,341,000
Loans Held-for-sale, Fair Value Disclosure	17,766,000	31,666,000
Derivative Assets	1,100,000	1,500,000
Impaired Loan Fair Value	7,484,000	6,924,000
Other loans	7,079,812,000	7,072,339,000
Loans receivable, net	7,106,142,000	7,112,474,000
Time deposits	827,039,000	870,804,000
Other	2,776,000	1,379,000
Total deposits	829,815,000	872,183,000
Short-term borrowings	305,385,000	342,230,000
Long-term debt	29,413,000	31,376,000
Subordinated debentures/notes	186,951,000	179,147,000
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	727,000	885,000
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Assets	1,080,000	1,545,000
Impaired Loan Fair Value		6,924,000
Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Swap	2,278,000	3,934,000
Loans [Member] | Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Assets	2,278,000	3,934,000
Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	2,012,000	2,511,000
Swap [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Swap	226,000	226,000
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and money market instruments	943,275,000	370,474,000
Derivative Assets	0	0
Other	2,776,000	1,379,000
Total deposits	2,776,000	1,379,000
Fair Value, Inputs, Level 1 [Member] | Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Assets	0	0
Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	1,522,000	2,026,000
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	1,115,284,000	1,059,341,000
Loans Held-for-sale, Fair Value Disclosure	17,766,000	31,666,000
Derivative Assets	1,080,000	1,545,000
Loans receivable, net	18,846,000	33,211,000
Time deposits	827,039,000	870,804,000
Total deposits	827,039,000	870,804,000
Short-term borrowings	305,385,000	342,230,000
Long-term debt	29,413,000	31,376,000
Subordinated debentures/notes	186,951,000	179,147,000
Fair Value, Inputs, Level 2 [Member] | Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Assets	2,278,000	3,934,000
Swap	2,278,000	3,934,000
Fair Value, Inputs, Level 2 [Member] | Swap [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	727,000	885,000
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Assets	0	0
Impaired Loan Fair Value	7,484,000	6,924,000
Other loans	7,079,812,000	7,072,339,000
Loans receivable, net	7,087,296,000	7,079,263,000
Fair Value, Inputs, Level 3 [Member] | Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Assets	0	0
Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	490,000	485,000
Fair Value, Inputs, Level 3 [Member] | Swap [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Swap	$ 226,000	$ 226,000