Fair Value Measurement (Schedule Of Fair Value Assets And Liabilities Measured On Recurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity and other investment securities	$ 72,277		$ 81,214
Investment securities available for sale	3,136,391		3,870,435
Loans held for sale	148,275		353,105
Loans Receivable, Fair Value Disclosure	284,900		345,634
Residential mortgage servicing rights, at fair value	196,177	$ 179,558	123,615	$ 105,834	$ 102,699	$ 92,907
Derivative Asset	14,829		177,423
Total assets measured at fair value	3,852,849		4,951,426
Junior subordinated debentures, at fair value	325,744		293,081
Derivative Liability	295,222		9,675
Total liabilities measured at fair value	620,966		302,756
Foreign currency derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	586		340
Derivative Liability	481		305
Investments in mutual funds and other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity and other investment securities	61,309		68,692
Equity securities held in rabbi trusts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity and other investment securities	10,968		12,522
U.S. Treasury and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available for sale	830,813		918,053
Obligations of states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available for sale	269,904		330,784
Mortgage-backed securities and collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available for sale	2,035,674		2,621,598
Interest rate lock commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	24		4,641
Derivative Liability	2,290
Interest rate futures
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	10,359
Interest rate forward sales commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	9,740		615
Derivative Liability	5		699
Interest rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	4,479		171,827
Derivative Liability	282,087		8,671
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	0		0
Loans Receivable, Fair Value Disclosure	0		0
Residential mortgage servicing rights, at fair value	0		0
Total assets measured at fair value	180,450		152,915
Junior subordinated debentures, at fair value	0		0
Total liabilities measured at fair value	0		0
Level 1 | Foreign currency derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0		0
Derivative Liability	0		0
Level 1 | Investments in mutual funds and other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity and other investment securities	43,972		51,355
Level 1 | Equity securities held in rabbi trusts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity and other investment securities	10,968		12,522
Level 1 | U.S. Treasury and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available for sale	125,510		89,038
Level 1 | Obligations of states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available for sale	0		0
Level 1 | Mortgage-backed securities and collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available for sale	0		0
Level 1 | Interest rate lock commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0		0
Derivative Liability	0
Level 1 | Interest rate futures
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	0
Level 1 | Interest rate forward sales commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0		0
Derivative Liability	0		0
Level 1 | Interest rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0		0
Derivative Liability	0		0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	148,275		353,105
Loans Receivable, Fair Value Disclosure	284,900		345,634
Residential mortgage servicing rights, at fair value	0		0
Total assets measured at fair value	3,476,198		4,670,255
Junior subordinated debentures, at fair value	0		0
Total liabilities measured at fair value	292,932		9,675
Level 2 | Foreign currency derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	586		340
Derivative Liability	481		305
Level 2 | Investments in mutual funds and other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity and other investment securities	17,337		17,337
Level 2 | Equity securities held in rabbi trusts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity and other investment securities	0		0
Level 2 | U.S. Treasury and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available for sale	705,303		829,015
Level 2 | Obligations of states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available for sale	269,904		330,784
Level 2 | Mortgage-backed securities and collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available for sale	2,035,674		2,621,598
Level 2 | Interest rate lock commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0		0
Derivative Liability	0
Level 2 | Interest rate futures
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	10,359
Level 2 | Interest rate forward sales commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	9,740		615
Derivative Liability	5		699
Level 2 | Interest rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	4,479		171,827
Derivative Liability	282,087		8,671
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	0		0
Loans Receivable, Fair Value Disclosure	0		0
Residential mortgage servicing rights, at fair value	196,177		123,615
Total assets measured at fair value	196,201		128,256
Junior subordinated debentures, at fair value	325,744		293,081
Total liabilities measured at fair value	328,034		293,081
Level 3 | Foreign currency derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0		0
Derivative Liability	0		0
Level 3 | Investments in mutual funds and other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity and other investment securities	0		0
Level 3 | Equity securities held in rabbi trusts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity and other investment securities	0		0
Level 3 | U.S. Treasury and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available for sale	0		0
Level 3 | Obligations of states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available for sale	0		0
Level 3 | Mortgage-backed securities and collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available for sale	0		0
Level 3 | Interest rate lock commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	24		4,641
Derivative Liability	2,290
Level 3 | Interest rate futures
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	0
Level 3 | Interest rate forward sales commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0		0
Derivative Liability	0		0
Level 3 | Interest rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0		0
Derivative Liability	$ 0		$ 0