Fair Value Accounting (Carrying And Estimated Fair Values Of Financial Instruments Carried On Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financial assets
Mortgage loans held for sale	$ 37,129	$ 48,024
Investment securities available for sale	3,991,632
Private equity investments	11,028	15,771
Loans, net	25,696,018	24,538,196
Derivative assets	19,332	11,722
Financial Liabilities
Non-interest-bearing deposits	7,650,967	7,686,339
Time deposits	5,003,396
Total deposits	26,720,322	26,147,900
Federal funds purchased and securities sold under repurchase agreements	237,692	161,190
Other short-term borrowings	650,000	100,000
Long-term debt	1,657,157	1,606,138
Level 1
Financial assets
Total cash, cash equivalents, restricted cash, and restricted cash equivalents	1,143,564	932,933
Trading account assets	1,128	522
Mortgage loans held for sale	0	0
Other loans held for sale	0	0
Investment securities available for sale	122,077	85,836
Private equity investments	0	0
Mutual funds	3,168
Mutual funds held in rabbi trusts	12,844	14,140
Loans, net	0	0
GGL/SBA loans servicing asset	0	0
Derivative assets	0	0
Financial Liabilities
Trading account liabilities		0
Non-interest-bearing deposits	0	0
Non-time interest-bearing deposits	0	0
Time deposits	0	0
Total deposits	0	0
Federal funds purchased and securities sold under repurchase agreements	237,692	161,190
Other short-term borrowings	0	0
Long-term debt	0	0
Earnout liability	0	0
Derivative liabilities	0	0
Level 2
Financial assets
Total cash, cash equivalents, restricted cash, and restricted cash equivalents	0	0
Trading account assets	2,002	3,298
Mortgage loans held for sale	37,129	48,024
Other loans held for sale	0	0
Investment securities available for sale	3,867,770	3,899,298
Private equity investments	0	0
Mutual funds	0
Mutual funds held in rabbi trusts	0	0
Loans, net	0	0
GGL/SBA loans servicing asset	0	0
Derivative assets	19,332	11,722
Financial Liabilities
Trading account liabilities		1,000
Non-interest-bearing deposits	7,650,967	7,686,339
Non-time interest-bearing deposits	14,065,959	13,941,814
Time deposits	4,989,570	4,523,661
Total deposits	26,706,496	26,151,814
Federal funds purchased and securities sold under repurchase agreements	0	0
Other short-term borrowings	650,000	100,000
Long-term debt	1,649,642	1,621,814
Earnout liability	0	0
Derivative liabilities	16,535	12,767
Level 3
Financial assets
Total cash, cash equivalents, restricted cash, and restricted cash equivalents	0	0
Trading account assets	0	0
Mortgage loans held for sale	0	0
Other loans held for sale	1,506	11,356
Investment securities available for sale	1,785	1,935
Private equity investments	11,028	15,771
Mutual funds	0
Mutual funds held in rabbi trusts	0	0
Loans, net	25,438,890	24,507,141
GGL/SBA loans servicing asset	3,729	4,101
Derivative assets	0	0
Financial Liabilities
Trading account liabilities		0
Non-interest-bearing deposits	0	0
Non-time interest-bearing deposits	0	0
Time deposits	0	0
Total deposits	0	0
Federal funds purchased and securities sold under repurchase agreements	0	0
Other short-term borrowings	0	0
Long-term debt	0	0
Earnout liability	14,353	11,348
Derivative liabilities	1,673	4,330
Carrying Value
Financial assets
Total cash, cash equivalents, restricted cash, and restricted cash equivalents	1,143,564	932,933
Trading account assets	3,130	3,820
Mortgage loans held for sale	37,129	48,024
Other loans held for sale	1,506	11,356
Investment securities available for sale	3,991,632	3,987,069
Private equity investments	11,028	15,771
Mutual funds	3,168
Mutual funds held in rabbi trusts	12,844	14,140
Loans, net	25,696,018	24,538,196
GGL/SBA loans servicing asset	3,729	4,101
Derivative assets	19,332	11,722
Financial Liabilities
Trading account liabilities		1,000
Non-interest-bearing deposits	7,650,967	7,686,339
Non-time interest-bearing deposits	14,065,959	13,941,814
Time deposits	5,003,396	4,519,747
Total deposits	26,720,322	26,147,900
Federal funds purchased and securities sold under repurchase agreements	237,692	161,190
Other short-term borrowings	650,000	100,000
Long-term debt	1,657,157	1,606,138
Earnout liability	14,353	11,348
Derivative liabilities	18,208	17,097
Estimated Fair Value
Financial assets
Total cash, cash equivalents, restricted cash, and restricted cash equivalents	1,143,564	932,933
Trading account assets	3,130	3,820
Mortgage loans held for sale	37,129	48,024
Other loans held for sale	1,506	11,356
Investment securities available for sale	3,991,632	3,987,069
Private equity investments	11,028	15,771
Mutual funds	3,168
Mutual funds held in rabbi trusts	12,844	14,140
Loans, net	25,438,890	24,507,141
GGL/SBA loans servicing asset	3,729	4,101
Derivative assets	19,332	11,722
Financial Liabilities
Trading account liabilities		1,000
Non-interest-bearing deposits	7,650,967	7,686,339
Non-time interest-bearing deposits	14,065,959	13,941,814
Time deposits	4,989,570	4,523,661
Total deposits	26,706,496	26,151,814
Federal funds purchased and securities sold under repurchase agreements	237,692	161,190
Other short-term borrowings	650,000	100,000
Long-term debt	1,649,642	1,621,814
Earnout liability	14,353	11,348
Derivative liabilities	$ 18,208	$ 17,097

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