Fair Value Measurements, Financial Instruments (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011	Dec. 31, 2010
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	$ 512,931,000		$ 710,739,000
Interest-bearing cash and cash equivalents	574,282,000		575,500,000
Trading securities	91,616,000		214,102,000
Investment securities	677,878,000	[1]	499,534,000	[2]
Available for sale securities	10,147,162,000		11,287,221,000
Fair value option securities	167,125,000		284,296,000
Residential mortgage loans held for sale	200,546,000		293,762,000
Loans	12,792,264,000		12,311,456,000
Allowance for loan losses	(185,396,000)		(215,507,000)		(253,481,000)	(292,971,000)
Loans, net of allowance	12,606,868,000		12,095,949,000
Mortgage servicing rights, net	153,333,000		100,812,000		86,783,000	115,723,000
Derivative contracts, net of cash margin, Assets, Fair Value	265,012,000		338,106,000
Time deposits	2,695,993,000		2,967,992,000
Subordinated debentures	347,802,000		347,633,000
Derivative contracts, net of cash margin, Liabilities, Fair Value	247,185,000		283,589,000
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Specific allocation of allowance for loan losses included in fair value of loans	157,000,000		171,000,000
Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	7,943,221,000		7,641,912,000
Allowance for loan losses	(79,180,000)		(65,280,000)		(83,443,000)	(104,631,000)
Commercial Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,415,353,000		2,228,999,000
Allowance for loan losses	(41,573,000)		(54,884,000)		(67,034,000)	(98,709,000)
Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,052,026,000		2,045,040,000
Allowance for loan losses	(29,465,000)		(41,703,000)		(46,476,000)	(50,281,000)
Consumer [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	381,664,000		395,505,000
Allowance for loan losses	(6,965,000)		(9,453,000)		(10,178,000)	(12,614,000)
U.S. Government agency debentures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	34,120,000		16,545,000
U.S. agency residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	21,011,000		86,361,000
Investment securities	50,182,000		82,767,000
Available for sale securities	7,716,010,000		9,889,821,000
Fair value option securities	157,431,000		257,040,000
Municipal and other tax-exempt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	27,350,000		90,326,000
Investment securities	440,187,000		232,700,000
Available for sale securities	73,775,000		87,142,000
Other trading securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	9,135,000		20,870,000
US Treasury Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	1,042,000		1,002,000
Privately issued residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	221,099,000		325,163,000
Commercial mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	2,055,804,000		895,075,000
Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	187,509,000		184,067,000
Available for sale securities	35,241,000		36,389,000
Fair value option securities	9,694,000		770,000
Perpetual preferred stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	22,863,000		25,072,000
Equity securities and mutual funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	21,328,000		27,557,000
Corporate debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value option securities	0		26,486,000
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	512,931,000		710,739,000
Interest-bearing cash and cash equivalents	574,282,000		575,500,000
Trading securities	91,616,000		214,102,000
Investment securities	677,878,000		499,534,000
Available for sale securities	10,147,162,000		11,287,221,000
Fair value option securities	167,125,000		284,296,000
Residential mortgage loans held for sale	334,250,000		293,762,000
Loans	12,792,264,000		12,311,456,000
Allowance for loan losses	(185,396,000)		(215,507,000)
Loans, net of allowance	12,606,868,000		12,095,949,000
Mortgage servicing rights, net	153,333,000		100,812,000
Derivative contracts, net of cash margin, Assets, Fair Value	265,012,000		338,106,000
Other assets, private equity funds	27,341,000		28,169,000
Deposits with no stated maturity	17,573,334,000		18,211,068,000
Time deposits	2,695,993,000		2,967,992,000
Other borrowings	2,721,888,000		2,706,221,000
Subordinated debentures	347,802,000		347,633,000
Derivative contracts, net of cash margin, Liabilities, Fair Value	247,185,000		283,589,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	7,943,221,000		7,641,912,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,415,353,000		2,228,999,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,052,026,000		2,045,040,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Consumer [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	381,664,000		395,505,000
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	34,120,000		16,545,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | U.S. agency residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	21,011,000		86,361,000
Investment securities	50,182,000		82,767,000
Available for sale securities	7,716,010,000		9,889,821,000
Fair value option securities	157,431,000		257,040,000
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	27,350,000		90,326,000
Investment securities	440,187,000		232,700,000
Available for sale securities	73,775,000		87,142,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Other trading securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	9,135,000		20,870,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | US Treasury Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	1,042,000		1,002,000
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	221,099,000		325,163,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	2,055,804,000		895,075,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	187,509,000		184,067,000
Available for sale securities	35,241,000		36,389,000
Fair value option securities	9,694,000		770,000
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	22,863,000		25,072,000
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	21,328,000		27,557,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Corporate debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value option securities	0		26,486,000
Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	512,931,000		710,739,000
Interest-bearing cash and cash equivalents	574,282,000		575,500,000
Trading securities	91,616,000		214,102,000
Investment securities	687,127,000		528,458,000
Available for sale securities	10,147,162,000		11,287,221,000
Fair value option securities	167,125,000		284,296,000
Residential mortgage loans held for sale	200,546,000		293,762,000
Loans	12,674,420,000		12,314,243,000
Allowance for loan losses	0		0
Loans, net of allowance	12,674,420,000		12,314,243,000
Mortgage servicing rights, net	153,333,000		100,812,000
Derivative contracts, net of cash margin, Assets, Fair Value	265,012,000		338,106,000
Other assets, private equity funds	27,341,000		28,169,000
Deposits with no stated maturity	17,573,334,000		18,211,068,000
Time deposits	2,697,290,000		3,441,610,000
Other borrowings	2,693,788,000		2,369,224,000
Subordinated debentures	344,783,000		411,243,000
Derivative contracts, net of cash margin, Liabilities, Fair Value	247,185,000		283,589,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	7,835,325,000		7,606,505,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,394,443,000		2,208,217,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,068,690,000		2,110,773,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Consumer [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	375,962,000		388,748,000
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	34,120,000		16,545,000
Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. agency residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	21,011,000		86,361,000
Investment securities	51,864,000		85,943,000
Available for sale securities	7,716,010,000		9,889,821,000
Fair value option securities	157,431,000		257,040,000
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	27,350,000		90,326,000
Investment securities	439,870,000		235,940,000
Available for sale securities	73,775,000		87,142,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Other trading securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	9,135,000		20,870,000
Estimate of Fair Value, Fair Value Disclosure [Member] | US Treasury Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	1,042,000		1,002,000
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	221,099,000		325,163,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	2,055,804,000		895,075,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	195,393,000		206,575,000
Available for sale securities	35,241,000		36,389,000
Fair value option securities	9,694,000		770,000
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	22,863,000		25,072,000
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	21,328,000		27,557,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Corporate debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value option securities	0		26,486,000
Contractual Yield, Minimum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Time deposits	0.0001		0.0001
Other borrowings	0.0025		0.0009
Subordinated debentures	0.0095		0.0100
Contractual Yield, Minimum [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0.0004		0.0021
Contractual Yield, Minimum [Member] | Commercial Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0.0038		0.0021
Contractual Yield, Minimum [Member] | Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0.0038		0.0038
Contractual Yield, Minimum [Member] | Consumer [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0.0038		0.0038
Contractual Yield, Maximum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Time deposits	0.0964		0.0964
Other borrowings	0.0478		0.0525
Subordinated debentures	0.0500		0.0500
Contractual Yield, Maximum [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0.3000		0.3000
Contractual Yield, Maximum [Member] | Commercial Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0.1800		0.1800
Contractual Yield, Maximum [Member] | Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0.1800		0.1800
Contractual Yield, Maximum [Member] | Consumer [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0.2100		0.2100
Average Repricing [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Time deposits	2.12		2.15
Other borrowings	0.03		0.00
Subordinated debentures	2.63		3.56
Average Repricing [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0.49		0.69
Average Repricing [Member] | Commercial Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0.78		0.92
Average Repricing [Member] | Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2.63		3.34
Average Repricing [Member] | Consumer [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0.55		0.32
Discount Rate, Minimum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Time deposits	0.0075		0.0080
Other borrowings	0.0008		0.0009
Subordinated debentures	0.0222		0.0240
Discount Rate, Minimum [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0.0048		0.0051
Discount Rate, Minimum [Member] | Commercial Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0.0121		0.0126
Discount Rate, Minimum [Member] | Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0.0059		0.0086
Discount Rate, Minimum [Member] | Consumer [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0.0122		0.0137
Discount Rate, Maximum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Time deposits	0.0133		0.0115
Other borrowings	0.0264		0.0267
Subordinated debentures	0.0222		0.0240
Discount Rate, Maximum [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0.0433		0.0359
Discount Rate, Maximum [Member] | Commercial Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0.0349		0.0318
Discount Rate, Maximum [Member] | Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0.0473		0.0309
Discount Rate, Maximum [Member] | Consumer [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	$ 0.0375		$ 0.0360

[1] Carrying value includes $1.8 million of net unrealized gain which remains in Accumulated other comprehensive income (“AOCI”) in the Consolidated Balance Sheets related to certain securities transferred from the Available for Sale securities portfolio to the Investment securities portfolio as discussed in greater detail following.

[2] Carrying value includes $5.0 million of net unrealized gain which remains in AOCI in the Consolidated Balance Sheets related to certain securities transferred from the Available for Sale securities portfolio to the Investment securities portfolio as discussed in greater detail following.