Fair Value Measurements, Financial Instruments (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	$ 1,956,923,000	$ 462,676,000
Investment securities	355,187,000	461,793,000
Available for sale securities	8,857,120,000	8,321,578,000
Fair value option securities	283,235,000	755,054,000
Residential mortgage loans held for sale	149,221,000	221,378,000
Loans	21,656,730,000	17,153,424,000
Allowance for loan losses	(207,457,000)	(230,682,000)	$ (246,159,000)	$ (225,524,000)
Loans, net of allowance	21,449,273,000	16,922,742,000
Mortgage servicing rights	259,254,000	252,867,000	247,073,000	218,605,000
Derivative contracts, net of cash margin, Assets, Fair Value	320,929,000	220,502,000
Time deposits	2,113,380,000	2,098,416,000
Subordinated debentures	275,913,000	144,677,000
Derivative contracts, net of cash margin, Liabilities, Fair Value	362,306,000	171,963,000
Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	13,636,078,000	10,733,975,000
Allowance for loan losses	(102,226,000)	(124,269,000)	(140,213,000)	(130,334,000)
Commercial Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	4,764,813,000	3,479,987,000
Allowance for loan losses	(60,026,000)	(56,621,000)	(50,749,000)	(41,391,000)
Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,230,033,000	1,973,686,000
Allowance for loan losses	(17,964,000)	(18,451,000)	(18,224,000)	(19,509,000)
Personal [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	1,025,806,000	965,776,000
Allowance for loan losses	(9,473,000)	(9,124,000)	$ (8,773,000)	$ (4,164,000)
U.S. government agency debentures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	63,765,000	21,196,000
U.S. government agency residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	1,791,584,000	392,673,000
Investment securities	12,612,000	15,891,000
Available for sale securities	5,804,708,000	5,309,152,000
Fair value option securities	283,235,000	755,054,000
Municipal and other tax-exempt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	34,507,000	13,559,000
Investment securities	137,296,000	228,186,000
Available for sale securities	2,864,000	27,080,000
Other trading securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	24,411,000	11,363,000
U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	493,000	1,000,000
Privately issued residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	59,736,000	93,221,000
Commercial mortgage-backed securities guaranteed by U.S. government agencies [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	2,953,889,000	2,834,961,000
Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	205,279,000	217,716,000
Available for sale securities	35,430,000	25,481,000
Perpetual preferred stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities		15,767,000
Equity securities and mutual funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities		14,916,000
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	741,749,000	602,510,000
Interest-bearing cash and cash equivalents	401,675,000	1,714,544,000
Trading securities	1,956,923,000	462,676,000
Investment securities	355,187,000	461,793,000
Available for sale securities	8,857,120,000	8,321,578,000
Residential mortgage loans held for sale	149,221,000	221,378,000
Loans	21,656,730,000	17,153,424,000
Allowance for loan losses	(207,457,000)	(230,682,000)
Loans, net of allowance	21,449,273,000	16,922,742,000
Mortgage servicing rights	259,254,000	252,867,000
Derivative contracts, net of cash margin, Assets, Fair Value	320,929,000	220,502,000
Deposits with no stated maturity	23,150,383,000	19,962,889,000
Time deposits	2,113,380,000	2,098,416,000
Other borrowed funds	7,142,801,000	5,709,860,000
Subordinated debentures	275,913,000	144,677,000
Derivative contracts, net of cash margin, Liabilities, Fair Value	362,306,000	171,963,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	13,636,078,000	10,733,975,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	4,764,813,000	3,479,987,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,230,033,000	1,973,686,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Personal [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	1,025,806,000	965,776,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | U.S. government agency debentures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	63,765,000	21,196,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | U.S. government agency residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	1,791,584,000	392,673,000
Investment securities	12,612,000	15,891,000
Available for sale securities	5,804,708,000	5,309,152,000
Fair value option securities	283,235,000	755,054,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	34,507,000	13,559,000
Investment securities	137,296,000	228,186,000
Available for sale securities	2,864,000	27,080,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Asset-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	42,656,000	23,885,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Other trading securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	24,411,000	11,363,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	493,000	1,000,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Privately issued residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	59,736,000	93,221,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	2,953,889,000	2,834,961,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	205,279,000	217,716,000
Available for sale securities	35,430,000	25,481,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Perpetual preferred stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities		15,767,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Equity securities and mutual funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities		14,916,000
Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	741,749,000	602,510,000
Interest-bearing cash and cash equivalents	401,675,000	1,714,544,000
Trading securities	1,956,923,000	438,791,000
Investment securities	367,298,000	480,035,000
Available for sale securities	8,857,120,000	8,321,578,000
Residential mortgage loans held for sale	149,221,000	221,378,000
Loans	21,478,228,000	16,887,787,000
Allowance for loan losses	0	0
Loans, net of allowance	21,478,228,000	16,887,787,000
Mortgage servicing rights	259,254,000	252,867,000
Derivative contracts, net of cash margin, Assets, Fair Value	320,929,000	220,502,000
Deposits with no stated maturity	23,150,383,000	19,962,889,000
Time deposits	2,073,538,000	2,064,558,000
Other borrowed funds	6,771,953,000	5,703,121,000
Subordinated debentures	261,977,000	148,207,000
Derivative contracts, net of cash margin, Liabilities, Fair Value	362,306,000	171,963,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	13,526,162,000	10,524,627,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	4,713,747,000	3,428,733,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,213,951,000	1,977,721,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Personal [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	1,024,368,000	956,706,000
Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency debentures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	63,765,000	21,196,000
Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	1,791,584,000	392,673,000
Investment securities	12,770,000	16,242,000
Available for sale securities	5,804,708,000	5,309,152,000
Fair value option securities	283,235,000	755,054,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	34,507,000	13,559,000
Investment securities	138,562,000	230,349,000
Available for sale securities	2,864,000	27,080,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Asset-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	42,656,000	23,885,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Other trading securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	24,411,000	11,363,000
Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	493,000	1,000,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Privately issued residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	59,736,000	93,221,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	2,953,889,000	2,834,961,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	215,966,000	233,444,000
Available for sale securities	35,430,000	25,481,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Perpetual preferred stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities		15,767,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Equity securities and mutual funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities		14,916,000
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	741,749,000	602,510,000
Interest-bearing cash and cash equivalents	401,675,000	1,714,544,000
Trading securities	0	0
Investment securities	0	0
Available for sale securities	493,000	1,000,000
Residential mortgage loans held for sale	0	0
Loans	0	0
Allowance for loan losses	0	0
Loans, net of allowance	0	0
Mortgage servicing rights	0	0
Derivative contracts, net of cash margin, Assets, Fair Value	44,074,000	8,179,000
Deposits with no stated maturity	0	0
Time deposits	0	0
Other borrowed funds	0	0
Subordinated debentures	0	0
Derivative contracts, net of cash margin, Liabilities, Fair Value	0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Personal [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency debentures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Investment securities	0	0
Available for sale securities	0	0
Fair value option securities	0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Investment securities	0	0
Available for sale securities	0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Asset-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other trading securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	493,000	1,000,000
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Privately issued residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	0	0
Available for sale securities	0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Perpetual preferred stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities		0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Equity securities and mutual funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities		0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	0	0
Interest-bearing cash and cash equivalents	0	0
Trading securities	1,956,923,000	438,791,000
Investment securities	159,237,000	480,035,000
Available for sale securities	8,856,155,000	8,315,304,000
Residential mortgage loans held for sale	134,014,000	208,946,000
Loans	0	0
Allowance for loan losses	0	0
Loans, net of allowance	0	0
Mortgage servicing rights	0	0
Derivative contracts, net of cash margin, Assets, Fair Value	276,855,000	212,323,000
Deposits with no stated maturity	0	0
Time deposits	0	0
Other borrowed funds	0	0
Subordinated debentures	261,977,000	148,207,000
Derivative contracts, net of cash margin, Liabilities, Fair Value	362,306,000	171,963,000
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0	0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0	0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0	0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Personal [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0	0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency debentures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	63,765,000	21,196,000
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	1,791,584,000	392,673,000
Investment securities	12,770,000	16,242,000
Available for sale securities	5,804,708,000	5,309,152,000
Fair value option securities	283,235,000	755,054,000
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	34,507,000	13,559,000
Investment securities	138,562,000	230,349,000
Available for sale securities	2,864,000	22,278,000
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Asset-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	42,656,000	23,885,000
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other trading securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	24,411,000	11,363,000
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0	0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Privately issued residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	59,736,000	93,221,000
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	2,953,889,000	2,834,961,000
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	7,905,000	233,444,000
Available for sale securities	34,958,000	25,009,000
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Perpetual preferred stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities		15,767,000
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Equity securities and mutual funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities		14,916,000
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	0	0
Interest-bearing cash and cash equivalents	0	0
Trading securities	0	0
Investment securities	208,061,000	0
Available for sale securities	472,000	5,274,000
Residential mortgage loans held for sale	15,207,000	12,432,000
Loans	21,478,228,000	16,887,787,000
Allowance for loan losses	0	0
Loans, net of allowance	21,478,228,000	16,887,787,000
Mortgage servicing rights	259,254,000	252,867,000
Derivative contracts, net of cash margin, Assets, Fair Value	0	0
Deposits with no stated maturity	23,150,383,000	19,962,889,000
Time deposits	2,073,538,000	2,064,558,000
Other borrowed funds	6,771,953,000	5,703,121,000
Subordinated debentures	0	0
Derivative contracts, net of cash margin, Liabilities, Fair Value	0	0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	13,526,162,000	10,524,627,000
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	4,713,747,000	3,428,733,000
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,213,951,000	1,977,721,000
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Personal [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	1,024,368,000	956,706,000
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency debentures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Investment securities	0	0
Available for sale securities	0	0
Fair value option securities	0	0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Investment securities	0	0
Available for sale securities	0	4,802,000
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Asset-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other trading securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0	0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Privately issued residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0	0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0	0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	208,061,000	0
Available for sale securities	$ 472,000	472,000
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Perpetual preferred stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities		0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Equity securities and mutual funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities		$ 0