Fair Value (Schedule Of Assets And Liabilities Measured At Fair Value By Class On A Recurring Basis) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value Level Transfers Among Levels 1, 2, and 3	0	0	0	0
Trading account	$ 38,278		$ 38,278		$ 28,290
Securities sold, not yet purchased	21,183		21,183		26,735
Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	289,880		289,880		322,196
Total assets	299,767		299,767		326,600
Securities sold, not yet purchased	21,183		21,183		26,735
Total liabilities	29,886		29,886		29,894
Level 1 [Member] | Mutual Funds And Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	251,382		251,382		219,214
Level 1 [Member] | Available-for-sale Securities [Member] | U.S. Treasury, Agencies And Corporations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	38,498		38,498		102,982
Level 1 [Member] | Derivatives [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	9,887		9,887		4,404
Other liabilities	8,703		8,703		3,159
Level 1 [Member] | Derivatives [Member] | Foreign Currency Exchange Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	9,887		9,887		4,404
Other liabilities	8,703		8,703		3,159
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	1,988,904		1,988,904		1,765,214
Trading account	38,278		38,278		28,290
Total assets	2,552,061		2,552,061		2,336,784
Securities sold, not yet purchased
Total liabilities	55,971		55,971		84,068
Level 2 [Member] | Mutual Funds And Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	5,649		5,649		8,797
Level 2 [Member] | Bank-owned life insurance [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other noninterest-bearing investments	464,180		464,180		455,719
Level 2 [Member] | Private Equity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other noninterest-bearing investments	4,992		4,992		5,132
Level 2 [Member] | Available-for-sale Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	2,000,000		2,000,000
Level 2 [Member] | Available-for-sale Securities [Member] | U.S. Treasury, Agencies And Corporations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	1,929,039		1,929,039		1,692,637
Level 2 [Member] | Available-for-sale Securities [Member] | Municipal Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	51,649		51,649		59,445
Level 2 [Member] | Asset-Backed Securities [Member] | Trust Preferred - Banks And Insurance [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities					121
Level 2 [Member] | Asset-Backed Securities [Member] | Other (Including ABS CDOs) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities					4,214
Level 2 [Member] | Asset-Backed Securities [Member] | Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	2,567		2,567
Level 2 [Member] | Derivatives [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	55,707		55,707		82,429
Other liabilities	55,971		55,971		84,068
Level 2 [Member] | Derivatives [Member] | Interest Rate Related And Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	1,067		1,067		2,850
Other liabilities	861		861		1,142
Level 2 [Member] | Derivatives [Member] | Interest Rate Swaps For Customers [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	54,640		54,640		79,579
Other liabilities	55,110		55,110		82,926
Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	1,055,105		1,055,105		1,003,900
Total assets	1,132,661		1,132,661		1,068,123
Other liabilities	197		197		124
Total liabilities	4,436		4,436		5,251
Level 3 [Member] | Private Equity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other noninterest-bearing investments	77,556		77,556		64,223
Level 3 [Member] | Available-for-sale Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	1,100,000		1,100,000
Level 3 [Member] | Available-for-sale Securities [Member] | Municipal Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	13,520		13,520		16,551
Level 3 [Member] | Asset-Backed Securities [Member] | Trust Preferred - Banks And Insurance [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	1,001,896		1,001,896		949,271
Level 3 [Member] | Asset-Backed Securities [Member] | Trust Preferred - Real Estate Investment Trusts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	19,517		19,517		16,403
Level 3 [Member] | Asset-Backed Securities [Member] | Auction Rate Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	6,625		6,625		6,515
Level 3 [Member] | Asset-Backed Securities [Member] | Other (Including ABS CDOs) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities					15,160
Level 3 [Member] | Asset-Backed Securities [Member] | Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	13,547		13,547
Level 3 [Member] | Derivatives [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other liabilities	4,239		4,239		5,127
Level 3 [Member] | Derivatives [Member] | Total Return Swap [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other liabilities	4,239		4,239		5,127
Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	3,333,889		3,333,889		3,091,310
Trading account	38,278		38,278		28,290
Total assets	3,984,489		3,984,489		3,731,507
Securities sold, not yet purchased	21,183		21,183		26,735
Other liabilities	197		197		124
Total liabilities	90,293		90,293		119,213
Estimated Fair Value [Member] | Mutual Funds And Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	257,031		257,031		228,011
Estimated Fair Value [Member] | Bank-owned life insurance [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other noninterest-bearing investments	464,180		464,180		455,719
Estimated Fair Value [Member] | Private Equity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other noninterest-bearing investments	82,548		82,548		69,355
Estimated Fair Value [Member] | Available-for-sale Securities [Member] | U.S. Treasury, Agencies And Corporations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	1,967,537		1,967,537		1,795,619
Estimated Fair Value [Member] | Available-for-sale Securities [Member] | Municipal Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	65,169		65,169		75,996
Estimated Fair Value [Member] | Asset-Backed Securities [Member] | Trust Preferred - Banks And Insurance [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	1,001,896		1,001,896		949,392
Estimated Fair Value [Member] | Asset-Backed Securities [Member] | Trust Preferred - Real Estate Investment Trusts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	19,517		19,517		16,403
Estimated Fair Value [Member] | Asset-Backed Securities [Member] | Auction Rate Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	6,625		6,625		6,515
Estimated Fair Value [Member] | Asset-Backed Securities [Member] | Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	16,114		16,114		19,374
Estimated Fair Value [Member] | Derivatives [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	65,594		65,594		86,833
Other liabilities	68,913		68,913		92,354
Estimated Fair Value [Member] | Derivatives [Member] | Interest Rate Related And Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	1,067		1,067		2,850
Other liabilities	861		861		1,142
Estimated Fair Value [Member] | Derivatives [Member] | Interest Rate Swaps For Customers [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	54,640		54,640		79,579
Other liabilities	55,110		55,110		82,926
Estimated Fair Value [Member] | Derivatives [Member] | Foreign Currency Exchange Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	9,887		9,887		4,404
Other liabilities	8,703		8,703		3,159
Estimated Fair Value [Member] | Derivatives [Member] | Total Return Swap [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other liabilities	$ 4,239		$ 4,239		$ 5,127