Fair Value Measurement (Schedule Of Carrying Value And Fair Value Of Financial Instruments Not Recorded At Fair Value) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Financial assets:
Equity and other investment securities	$ 81,575		$ 83,077
Investment securities available for sale	3,723,171		2,932,558
Investment securities held to maturity	2,795		3,034
Loans held for sale	352,466		688,079
Loans and leases, net	21,712,380		21,450,966
Restricted equity securities	10,946		41,666
Residential mortgage servicing rights	105,834	$ 102,699	92,907	$ 93,248	$ 96,356	$ 115,010
Bank owned life insurance	325,646		323,470
Derivatives	210,688		342,510
Financial liabilities:
Deposits	26,908,397		24,622,201
Securities sold under agreements to repurchase	467,760		375,384
Borrowings	6,367		771,482
Junior subordinated debentures, at fair value	299,508		255,217
Junior subordinated debentures, at amortized cost	88,098		88,268
Derivatives	9,661		8,782
Carrying Value
Financial assets:
Cash and cash equivalents	3,744,589		2,573,181
Equity and other investment securities	81,575		83,077
Investment securities available for sale	3,723,171		2,932,558
Investment securities held to maturity	2,795		3,034
Loans held for sale	352,466		766,225
Loans and leases, net	21,712,380		21,450,966
Restricted equity securities	10,946		41,666
Residential mortgage servicing rights	105,834		92,907
Bank owned life insurance	325,646		323,470
Derivatives	210,688		342,510
Financial liabilities:
Deposits	26,908,397		24,622,201
Securities sold under agreements to repurchase	467,760		375,384
Borrowings	6,367		771,482
Junior subordinated debentures, at fair value	299,508		255,217
Junior subordinated debentures, at amortized cost	88,098		88,268
Derivatives	9,661		8,782
Fair Value
Financial assets:
Cash and cash equivalents	3,744,589		2,573,181
Equity and other investment securities	81,575		83,077
Investment securities available for sale	3,723,171		2,932,558
Investment securities held to maturity	3,581		3,883
Loans held for sale	352,466		766,225
Loans and leases, net	21,853,775		21,904,189
Restricted equity securities	10,946		41,666
Residential mortgage servicing rights	105,834		92,907
Bank owned life insurance	325,646		323,470
Derivatives	210,688		342,510
Financial liabilities:
Deposits	26,911,910		24,641,876
Securities sold under agreements to repurchase	467,760		375,384
Borrowings	7,160		774,586
Junior subordinated debentures, at fair value	299,508		255,217
Junior subordinated debentures, at amortized cost	76,686		67,425
Derivatives	$ 9,661		$ 8,782