Fair Value Measurement (Schedule Of Fair Value Assets And Liabilities Measured On Recurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value	$ 9,509		$ 9,999
Available for sale, at fair value	2,482,478		2,298,555
Loans held for sale, at fair value	395,421		286,802
Residential mortgage servicing rights, at fair value	124,814	$ 127,206	117,259	$ 118,725	$ 114,192	$ 47,765
Derivatives, assets	50,608		29,775
Total assets measured at fair value	3,062,830		2,742,390
Junior subordinated debentures, at fair value	253,665		249,294
Derivatives, liabilities	52,796		30,888
Total liabilities measured at fair value	306,461		280,182
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Residential mortgage servicing rights, at fair value	0		0
Total assets measured at fair value	9,268		5,283
Junior subordinated debentures, at fair value	0		0
Total liabilities measured at fair value	0		0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale, at fair value	395,421		286,802
Residential mortgage servicing rights, at fair value	0		0
Total assets measured at fair value	2,923,282		2,616,981
Junior subordinated debentures, at fair value	0		0
Total liabilities measured at fair value	52,796		30,888
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Residential mortgage servicing rights, at fair value	124,814		117,259
Total assets measured at fair value	130,280		120,126
Junior subordinated debentures, at fair value	253,665		249,294
Total liabilities measured at fair value	253,665		249,294
Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	6		565
Derivatives, liabilities	5		103
Foreign Exchange Contract [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	0		0
Derivatives, liabilities	0		0
Foreign Exchange Contract [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	6		565
Derivatives, liabilities	5		103
Foreign Exchange Contract [Member] | Level 3 [Member]
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 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	5,466		2,867
Interest Rate Lock Commitments [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	0		0
Interest Rate Lock Commitments [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	0		0
Interest Rate Lock Commitments [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	5,466		2,867
Interest Rate Forward Sales Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	2		16
Derivatives, liabilities	5,271		2,627
Interest Rate Forward Sales Commitments [Member] | Level 1 [Member]
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 [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	2		16
Derivatives, liabilities	5,271		2,627
Interest Rate Forward Sales Commitments [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	0		0
Derivatives, liabilities	0		0
Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	45,134		26,327
Derivatives, liabilities	47,520		28,158
Interest Rate Swap [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	0		0
Derivatives, liabilities	0		0
Interest Rate Swap [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, assets	45,134		26,327
Derivatives, liabilities	47,520		28,158
Interest Rate Swap [Member] | Level 3 [Member]
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 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value	241		124
Available for sale, at fair value	326,464		338,404
Obligations Of States And Political Subdivisions [Member] | Level 1 [Member]
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 [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value	241		124
Available for sale, at fair value	326,464		338,404
Obligations Of States And Political Subdivisions [Member] | Level 3 [Member]
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 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value	9,268		5,283
Equity Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value	9,268		5,283
Equity Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value	0		0
Equity Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value	0		0
Other Investment Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value			4,592
Other Investment Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value			0
Other Investment Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value			4,592
Other Investment Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading, at fair value			0
U.S. Treasury And Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value			229
U.S. Treasury And Agencies [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value			0
U.S. Treasury And Agencies [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value			229
U.S. Treasury And Agencies [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value			0
Residential Mortgage-Backed Securities And Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	2,153,933		1,957,852
Residential Mortgage-Backed Securities And Collateralized Mortgage Obligations [Member] | Level 1 [Member]
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 [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	2,153,933		1,957,852
Residential Mortgage-Backed Securities And Collateralized Mortgage Obligations [Member] | Level 3 [Member]
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 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	2,081		2,070
Investments In Mutual Funds And Other Equity Securities [Member] | Level 1 [Member]
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 [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	2,081		2,070
Investments In Mutual Funds And Other Equity Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	$ 0		$ 0