Fair Value Accounting (Carrying And Estimated Fair Values Of Financial Instruments Carried On Balance Sheet) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Financial assets
Total investment securities available for sale	$ 7,962,438		$ 6,778,670
Mortgage loans held for sale	760,123		115,173
Private equity investments	1,021		19,389
Mutual funds and mutual funds held in rabbi trusts	37,650		32,348
Loans, net		$ 36,881,048
Derivative assets	401,295		140,016
Financial Liabilities
Non-interest-bearing deposits	13,477,854		9,439,485
Time deposits	5,948,196
Total deposits	46,691,571		38,405,504
Securities sold under repurchase agreements	227,922		165,690
Other short-term borrowings	7,717		1,753,560
Long-term debt	1,202,494		2,153,897
Level 1
Financial assets
Total cash, cash equivalents, and restricted cash	4,252,917		1,186,918
Trading securities	0		0
Total investment securities available for sale	20,257		19,855
Mortgage loans held for sale	0		0
Private equity investments	0		15,502
Mutual funds and mutual funds held in rabbi trusts	37,650		32,348
Loans, net	0		0
GGL/SBA loans servicing asset	0		0
Derivative assets	0		0
Financial Liabilities
Non-interest-bearing deposits	0		0
Non-time interest-bearing deposits	0		0
Time deposits	0		0
Total deposits	0		0
Securities sold under repurchase agreements	227,922		165,690
Trading liability for short positions	0		1,560
Other short-term borrowings			0
Long-term debt	0		0
Earnout liability	0		0
Derivative liabilities	0		0
Level 2
Financial assets
Total cash, cash equivalents, and restricted cash	0		0
Trading securities	10,880		7,212
Total investment securities available for sale	7,940,160		6,756,710
Mortgage loans held for sale	216,647		115,173
Private equity investments	0		0
Mutual funds and mutual funds held in rabbi trusts	0		0
Loans, net	0		0
GGL/SBA loans servicing asset	0		0
Derivative assets	401,295		140,016
Financial Liabilities
Non-interest-bearing deposits	13,477,854		9,439,485
Non-time interest-bearing deposits	27,265,521		19,891,711
Time deposits	5,970,146		9,112,459
Total deposits	46,713,521		38,443,655
Securities sold under repurchase agreements	0		0
Trading liability for short positions	7,717		0
Other short-term borrowings			1,752,000
Long-term debt	1,266,825		2,185,717
Earnout liability	0		0
Derivative liabilities	155,119		34,732
Level 3
Financial assets
Total cash, cash equivalents, and restricted cash	0		0
Trading securities	0		0
Total investment securities available for sale	2,021		2,105
Mortgage loans held for sale	544,292		0
Private equity investments	1,021		3,887
Mutual funds and mutual funds held in rabbi trusts	0		0
Loans, net	37,605,881		36,931,256
GGL/SBA loans servicing asset	3,258		3,040
Derivative assets	0		0
Financial Liabilities
Non-interest-bearing deposits	0		0
Non-time interest-bearing deposits	0		0
Time deposits	0		0
Total deposits	0		0
Securities sold under repurchase agreements	0		0
Trading liability for short positions	0		0
Other short-term borrowings			0
Long-term debt	0		0
Earnout liability	5,677		11,016
Derivative liabilities	$ 2,048		2,339
Level 3 | Weighted Average [Member] | Other Assets Held for Sale [Member] | Fair Value, Measurements, Nonrecurring | Third-party appraised value less estimated selling costs or BOV [Member]
Financial Liabilities
Fair Value Inputs, Estimated selling costs	7.00%
Carrying Value
Financial assets
Total cash, cash equivalents, and restricted cash	$ 4,252,917		1,186,918
Trading securities	10,880		7,212
Total investment securities available for sale	7,962,438		6,778,670
Mortgage loans held for sale	760,123		115,173
Private equity investments	1,021		19,389
Mutual funds and mutual funds held in rabbi trusts	37,650		32,348
Loans, net	37,647,248		36,881,048
GGL/SBA loans servicing asset	3,258		3,040
Derivative assets	401,295		140,016
Financial Liabilities
Non-interest-bearing deposits	13,477,854		9,439,485
Non-time interest-bearing deposits	27,265,521		19,891,711
Time deposits	5,948,196		9,074,308
Total deposits	46,691,571		38,405,504
Securities sold under repurchase agreements	227,922		165,690
Trading liability for short positions	7,717		1,560
Other short-term borrowings			1,752,000
Long-term debt	1,202,494		2,153,897
Earnout liability	5,677		11,016
Derivative liabilities	157,167		37,071
Estimated Fair Value
Financial assets
Total cash, cash equivalents, and restricted cash	4,252,917		1,186,918
Trading securities	10,880		7,212
Total investment securities available for sale	7,962,438		6,778,670
Mortgage loans held for sale	760,939		115,173
Private equity investments	1,021		19,389
Mutual funds and mutual funds held in rabbi trusts	37,650		32,348
Loans, net	37,605,881		36,931,256
GGL/SBA loans servicing asset	3,258		3,040
Derivative assets	401,295		140,016
Financial Liabilities
Non-interest-bearing deposits	13,477,854		9,439,485
Non-time interest-bearing deposits	27,265,521		19,891,711
Time deposits	5,970,146		9,112,459
Total deposits	46,713,521		38,443,655
Securities sold under repurchase agreements	227,922		165,690
Trading liability for short positions	7,717		1,560
Other short-term borrowings			1,752,000
Long-term debt	1,266,825		2,185,717
Earnout liability	5,677		11,016
Derivative liabilities	$ 157,167		$ 37,071