Fair Value (Schedule Of Assets And Liabilities Measured At Fair Value By Class On A Recurring Basis) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading account	$ 74,519	$ 70,601
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	4,549,055	3,336,943
Trading account	74,519	70,601
Total assets	5,151,101	3,933,629
Securities sold, not yet purchased	0	0
Total liabilities	45,996	50,966
Level 2 [Member] | Mutual Funds And Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	8,316	30,275
Level 2 [Member] | Bank-owned life insurance [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other noninterest-bearing investments	$ 479,596	$ 476,290
Level 2 [Member] | Private Equity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other noninterest-bearing investments
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]
Investments, Fair Value Disclosure	$ 4,314,267	$ 3,098,208
Level 2 [Member] | Available-for-sale Securities [Member] | Municipal Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	202,657	185,093
Level 2 [Member] | Available-for-sale Securities [Member] | Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	23,815
Level 2 [Member] | Asset-Backed Securities [Member] | Banks, Trust and Insurance, Equities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		22,701
Level 2 [Member] | Asset-Backed Securities [Member] | Other (Including ABS CDOs) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		666
Level 2 [Member] | Derivatives [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	47,931	49,795
Other Liabilities, Fair Value Disclosure	45,996	50,966
Level 2 [Member] | Derivatives [Member] | Interest Rate Related And Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	3,963	1,508
Other Liabilities, Fair Value Disclosure	398	297
Level 2 [Member] | Derivatives [Member] | Interest Rate Swaps [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	43,968	48,287
Other Liabilities, Fair Value Disclosure	45,598	50,669
Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	0	401,957
Total assets	123,617	514,049
Securities sold, not yet purchased	0	0
Other Liabilities, Fair Value Disclosure		13
Total liabilities	0	13
Level 3 [Member] | Private Equity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other noninterest-bearing investments	110,115	99,865
Level 3 [Member] | Interest-Only-Strip [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	13,502	12,227
Level 3 [Member] | Available-for-sale Securities [Member] | U.S. Treasury, Agencies And Corporations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	$ 0	0
Level 3 [Member] | Available-for-sale Securities [Member] | Municipal Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		4,164
Level 3 [Member] | Asset-Backed Securities [Member] | Banks, Trust and Insurance, Equities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		393,007
Level 3 [Member] | Asset-Backed Securities [Member] | Auction Rate Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		4,761
Level 3 [Member] | Asset-Backed Securities [Member] | Other (Including ABS CDOs) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		25
Level 3 [Member] | Derivatives [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	$ 0	0
Other Liabilities, Fair Value Disclosure	0	0
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	4,652,415	3,844,248
Trading account	74,519	70,601
Total assets	5,484,422	4,658,529
Securities sold, not yet purchased	11,397	24,230
Other Liabilities, Fair Value Disclosure		13
Total liabilities	161,371	179,359
Estimate of Fair Value Measurement [Member] | Mutual Funds And Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	111,676	135,623
Estimate of Fair Value Measurement [Member] | Bank-owned life insurance [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other noninterest-bearing investments	479,596	476,290
Estimate of Fair Value Measurement [Member] | Private Equity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other noninterest-bearing investments	110,115	99,865
Estimate of Fair Value Measurement [Member] | Interest-Only-Strip [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	13,502	12,227
Estimate of Fair Value Measurement [Member] | Available-for-sale Securities [Member] | U.S. Treasury, Agencies And Corporations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	4,314,267	3,098,208
Estimate of Fair Value Measurement [Member] | Available-for-sale Securities [Member] | Municipal Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	202,657	189,257
Estimate of Fair Value Measurement [Member] | Available-for-sale Securities [Member] | Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	23,815
Estimate of Fair Value Measurement [Member] | Asset-Backed Securities [Member] | Banks, Trust and Insurance, Equities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		415,708
Estimate of Fair Value Measurement [Member] | Asset-Backed Securities [Member] | Auction Rate Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		4,761
Estimate of Fair Value Measurement [Member] | Asset-Backed Securities [Member] | Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		691
Estimate of Fair Value Measurement [Member] | Derivatives [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	64,546	66,420
Other Liabilities, Fair Value Disclosure	60,245	66,238
Estimate of Fair Value Measurement [Member] | Derivatives [Member] | Interest Rate Related And Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	3,963	1,508
Other Liabilities, Fair Value Disclosure	398	297
Estimate of Fair Value Measurement [Member] | Derivatives [Member] | Interest Rate Swaps [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	43,968	48,287
Other Liabilities, Fair Value Disclosure	45,598	50,669
Estimate of Fair Value Measurement [Member] | Derivatives [Member] | Foreign Currency Exchange Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	16,615	16,625
Other Liabilities, Fair Value Disclosure	14,249	15,272
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	103,360	105,348
Total assets	209,704	210,851
Securities sold, not yet purchased	11,397	24,230
Total liabilities	115,375	128,380
Fair Value, Inputs, Level 1 [Member] | Mutual Funds And Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	103,360	105,348
Fair Value, Inputs, 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]
Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 [Member] | Derivatives [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	16,615	16,625
Other Liabilities, Fair Value Disclosure	14,249	15,272
Fair Value, Inputs, Level 1 [Member] | Derivatives [Member] | Foreign Currency Exchange Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	16,615	16,625
Other Liabilities, Fair Value Disclosure	$ 14,249	$ 15,272