Fair Value Measurement (Schedule Of Fair Value Assets And Liabilities Measured On Recurring Basis) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value	$ 11,241	$ 10,964
Available for sale, at fair value	3,243,408	2,701,220
Loans held for sale, at fair value	372,073	387,318
Residential mortgage servicing rights, at fair value	142,344	142,973	$ 117,172	$ 131,817
Derivatives, assets	34,029	47,501
Total assets measured at fair value	3,803,095	3,289,976
Junior subordinated debentures, at fair value	263,605	262,209
Derivatives, liabilities	10,438	37,063
Total liabilities measured at fair value	274,043	299,272
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale, at fair value	0	0
Residential mortgage servicing rights, at fair value	0	0
Total assets measured at fair value	11,030	10,302
Junior subordinated debentures, at fair value	0	0
Total liabilities measured at fair value	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale, at fair value	372,073	387,318
Residential mortgage servicing rights, at fair value	0	0
Total assets measured at fair value	3,643,427	3,132,625
Junior subordinated debentures, at fair value	0	0
Total liabilities measured at fair value	10,438	37,063
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale, at fair value	0	0
Residential mortgage servicing rights, at fair value	142,344	142,973
Total assets measured at fair value	148,638	147,049
Junior subordinated debentures, at fair value	263,605	262,209
Total liabilities measured at fair value	263,605	262,209
Foreign Exchange Contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	289	670
Derivatives, liabilities	298	874
Foreign Exchange Contract | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	0	0
Derivatives, liabilities	0	0
Foreign Exchange Contract | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	289	670
Derivatives, liabilities	298	874
Foreign Exchange Contract | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	0	0
Derivatives, liabilities	0	0
Interest Rate Lock Commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	6,294	4,076
Interest Rate Lock Commitments | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	0	0
Interest Rate Lock Commitments | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	0	0
Interest Rate Lock Commitments | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	6,294	4,076
Interest Rate Forward Sales Commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	78	8,054
Derivatives, liabilities	3,807	1,318
Interest Rate Forward Sales Commitments | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	0	0
Derivatives, liabilities	0	0
Interest Rate Forward Sales Commitments | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	78	8,054
Derivatives, liabilities	3,807	1,318
Interest Rate Forward Sales Commitments | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	0	0
Derivatives, liabilities	0	0
Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	27,368	34,701
Derivatives, liabilities	6,333	34,871
Interest Rate Swap | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	0	0
Derivatives, liabilities	0	0
Interest Rate Swap | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	27,368	34,701
Derivatives, liabilities	6,333	34,871
Interest Rate Swap | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	0	0
Derivatives, liabilities	0	0
Obligations Of States And Political Subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value	211	662
Available for sale, at fair value	307,219	307,697
Obligations Of States And Political Subdivisions | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value	0	0
Available for sale, at fair value	0	0
Obligations Of States And Political Subdivisions | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value	211	662
Available for sale, at fair value	307,219	307,697
Obligations Of States And Political Subdivisions | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value	0	0
Available for sale, at fair value	0	0
Equity Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value	11,030	10,302
Equity Securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value	11,030	10,302
Equity Securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value	0	0
Equity Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value	0	0
Residential Mortgage-Backed Securities And Collateralized Mortgage Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	2,934,219	2,391,553
Residential Mortgage-Backed Securities And Collateralized Mortgage Obligations | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	0	0
Residential Mortgage-Backed Securities And Collateralized Mortgage Obligations | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	2,934,219	2,391,553
Residential Mortgage-Backed Securities And Collateralized Mortgage Obligations | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	0	0
Investments In Mutual Funds And Other Equity Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	1,970	1,970
Investments In Mutual Funds And Other Equity Securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	0	0
Investments In Mutual Funds And Other Equity Securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	1,970	1,970
Investments In Mutual Funds And Other Equity Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	$ 0	$ 0