Fair Value Accounting (Carrying And Estimated Fair Values Of Financial Instruments Carried On Balance Sheet) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	$ 469,630	$ 614,630
Interest bearing funds with Federal Reserve Bank	644,528	1,498,390
Interest earning deposits with banks	24,325	23,442
Federal funds sold and securities purchased under resale agreements	80,975	113,517
Trading account assets	6,113	11,102
Mortgage loans held for sale	45,384	212,663
Other loans held for sale	10,685	10,690
Investment securities available for sale	3,199,358	2,981,112
Private equity investments	29,361	31,876
Loans, net	19,750,238	19,168,285
Derivative asset positions	40,004	64,662
Non-interest bearing deposits	5,642,751	5,665,527
Interest bearing deposits	15,234,039	15,391,517
Federal funds purchased and other short-term borrowings	148,132	201,243	313,757
Long-term debt	2,033,141	1,726,455
Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	469,630	614,630
Interest bearing funds with Federal Reserve Bank	644,528	1,498,390
Interest earning deposits with banks	24,325	23,442
Federal funds sold and securities purchased under resale agreements	80,975	113,517
Trading account assets	0	0
Mortgage loans held for sale	0	0
Other loans held for sale	0	0
Investment securities available for sale	26,716	3,205
Private equity investments	0	0
Mutual funds held In Rabbi Trusts	11,246	10,001
Loans, net	0	0
Derivative asset positions	0	0
Trading account liabilities	0	0
Non-interest bearing deposits	0	0
Interest bearing deposits	0	0
Federal funds purchased and other short-term borrowings	0	0
Salary stock units	1,764	1,888
Long-term debt	0	0
Derivative liability positions	0	0
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	0	0
Interest bearing funds with Federal Reserve Bank	0	0
Interest earning deposits with banks	0	0
Federal funds sold and securities purchased under resale agreements	0	0
Trading account assets	6,113	11,102
Mortgage loans held for sale	45,384	212,663
Other loans held for sale	0	0
Investment securities available for sale	3,170,292	2,974,729
Private equity investments	1,615	1,168
Mutual funds held In Rabbi Trusts	0	0
Loans, net	0	0
Derivative asset positions	40,004	64,662
Trading account liabilities	1,763	91
Non-interest bearing deposits	5,642,751	5,665,527
Interest bearing deposits	15,244,020	15,415,160
Federal funds purchased and other short-term borrowings	148,132	201,243
Salary stock units	0	0
Long-term debt	2,095,720	1,784,223
Derivative liability positions	39,436	63,437
Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	0	0
Interest bearing funds with Federal Reserve Bank	0	0
Interest earning deposits with banks	0	0
Federal funds sold and securities purchased under resale agreements	0	0
Trading account assets	0	0
Mortgage loans held for sale	0	0
Other loans held for sale	10,685	10,690
Investment securities available for sale	2,350	3,178
Private equity investments	27,745	30,708
Mutual funds held In Rabbi Trusts	0	0
Loans, net	19,763,708	19,254,199
Derivative asset positions	0	0
Trading account liabilities	0	0
Non-interest bearing deposits	0	0
Interest bearing deposits	0	0
Federal funds purchased and other short-term borrowings	0	0
Salary stock units	0	0
Long-term debt	0	0
Derivative liability positions	2,706	2,956
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	469,630	614,630
Interest bearing funds with Federal Reserve Bank	644,528	1,498,390
Interest earning deposits with banks	24,325	23,442
Federal funds sold and securities purchased under resale agreements	80,975	113,517
Trading account assets	6,113	11,102
Mortgage loans held for sale	45,384	212,663
Other loans held for sale	10,685	10,690
Investment securities available for sale	3,199,358	2,981,112
Private equity investments	29,360	31,876
Mutual funds held In Rabbi Trusts	11,246	10,001
Loans, net	20,057,798	19,541,690
Derivative asset positions	40,004	64,662
Trading account liabilities	1,763	91
Non-interest bearing deposits	5,642,751	5,665,527
Interest bearing deposits	15,234,039	15,391,517
Federal funds purchased and other short-term borrowings	148,132	201,243
Salary stock units	1,764	1,888
Long-term debt	2,033,141	1,726,455
Derivative liability positions	42,142	66,393
Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	469,630	614,630
Interest bearing funds with Federal Reserve Bank	644,528	1,498,390
Interest earning deposits with banks	24,325	23,442
Federal funds sold and securities purchased under resale agreements	80,975	113,517
Trading account assets	6,113	11,102
Mortgage loans held for sale	45,384	212,663
Other loans held for sale	10,685	10,690
Investment securities available for sale	3,199,358	2,981,112
Private equity investments	29,360	31,876
Mutual funds held In Rabbi Trusts	11,246	10,001
Loans, net	19,763,708	19,254,199
Derivative asset positions	40,004	64,662
Trading account liabilities	1,763	91
Non-interest bearing deposits	5,642,751	5,665,527
Interest bearing deposits	15,244,020	15,415,160
Federal funds purchased and other short-term borrowings	148,132	201,243
Salary stock units	1,764	1,888
Long-term debt	2,095,720	1,784,223
Derivative liability positions	42,142	66,393
Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	$ 7,584	$ 3,740