Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2017

Fair Value Assets And Liabilities Measured On A Recurring Basis [Table Text Block]

The fair value of financial assets and liabilities measured on a recurring basis was as follows as of June 30, 2017 (in thousands):



	Total		Quoted Prices in Active Markets for Identical Instruments (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Trading securities:
U.S. government agency debentures	$	20,954	$	—	$	20,954	$	—
U.S. government agency residential mortgage-backed securities	365,171		—		365,171		—
Municipal and other tax-exempt securities	45,444		—		45,444		—
Other trading securities	9,845		—		9,845		—
Total trading securities	441,414		—		441,414		—
Available for sale securities:
U.S. Treasury	998		998		—		—
Municipal and other tax-exempt securities	32,765		—		28,110		4,655
U.S. government agency residential mortgage-backed securities	5,382,377		—		5,382,377		—
Privately issued residential mortgage-backed securities	103,383		—		103,383		—
Commercial mortgage-backed securities guaranteed by U.S. government agencies	2,782,070		—		2,782,070		—
Other debt securities	4,152		—		—		4,152
Perpetual preferred stock	16,568		—		16,568		—
Equity securities and mutual funds	18,728		3,516		15,212		—
Total available for sale securities	8,341,041		4,514		8,327,720		8,807
Fair value option securities – U.S. government agency residential mortgage-backed securities	445,169		—		445,169		—
Residential mortgage loans held for sale	287,259		—		274,524		12,735
Mortgage servicing rights¹	245,239		—		—		245,239
Derivative contracts, net of cash collateral²	280,289		20,213		260,076		—
Liabilities:
Derivative contracts, net of cash collateral²	285,819		5,919		279,900		—


¹	A reconciliation of the beginning and ending fair value of mortgage servicing rights and disclosures of significant assumptions used to determine fair value are presented in Note 6, Mortgage Banking Activities.

See Note 3 for detail of fair value of derivative contracts by contract type. Derivative contracts in asset positions that were valued based on quoted prices in active markets for identical instruments (Level 1) are primarily exchange-traded energy and interest rate derivative contacts. Derivative contacts in liability positions that were valued using quoted prices in active markets for identical instruments are exchange-traded interest rate and agricultural derivative contracts, net of cash margin.

The fair value of financial assets and liabilities measured on a recurring basis was as follows as of December 31, 2016 (in thousands):



	Total		Quoted Prices in Active Markets for Identical Instruments (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Trading securities:
U.S. government agency debentures	$	6,234	$	—	$	6,234	$	—
U.S. government agency residential mortgage-backed securities	310,067		—		310,067		—
Municipal and other tax-exempt securities	14,427		—		14,427		—
Other trading securities	6,900		—		6,900		—
Total trading securities	337,628		—		337,628		—
Available for sale securities:
U.S. Treasury	999		999		—		—
Municipal and other tax-exempt securities	40,993		—		35,204		5,789
U.S. government agency residential mortgage-backed securities	5,460,386		—		5,460,386		—
Privately issued residential mortgage-backed securities	115,535		—		115,535		—
Commercial mortgage-backed securities guaranteed by U.S. government agencies	3,017,933		—		3,017,933		—
Other debt securities	4,152		—		—		4,152
Perpetual preferred stock	18,474		—		18,474		—
Equity securities and mutual funds	18,357		3,495		14,862		—
Total available for sale securities	8,676,829		4,494		8,662,394		9,941
Fair value option securities – U.S. government agency residential mortgage-backed securities	77,046		—		77,046		—
Residential mortgage loans held for sale	301,897		—		290,280		11,617
Mortgage servicing rights¹	247,073		—		—		247,073
Derivative contracts, net of cash collateral²	689,872		7,541		682,331		—
Liabilities:
Derivative contracts, net of cash collateral²	664,531		6,972		657,559		—


¹	A reconciliation of the beginning and ending fair value of mortgage servicing rights and disclosures of significant assumptions used to determine fair value are presented in Note 6, Mortgage Banking Activities.

See Note 3 for detail of fair value of derivative contracts by contract type. Derivative contracts based on quoted prices in active markets for identical instruments (Level 1) are exchange-traded interest-rate and energy derivative contacts, net of cash margin. Derivative contracts in liability positions that were valued using quoted prices in active markets for identical instruments (Level 1) are exchange-traded interest rate, energy and agricultural derivative contracts, net of cash margin.

The fair value of financial assets and liabilities measured on a recurring basis was as follows as of June 30, 2016 (in thousands):



	Total		Quoted Prices in Active Markets for Identical Instruments (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Trading securities:
U.S. government agency debentures	$	18,909	$	—	$	18,909	$	—
U.S. government agency residential mortgage-backed securities	122,306		—		122,306		—
Municipal and other tax-exempt securities	52,721		—		52,721		—
Other trading securities	17,686		—		17,686		—
Total trading securities	211,622		—		211,622		—
Available for sale securities:
U.S. Treasury	1,004		1,004		—		—
Municipal and other tax-exempt securities	50,262		—		40,662		9,600
U.S. government agency residential mortgage-backed securities	5,700,268		—		5,700,268		—
Privately issued residential mortgage-backed securities	126,313		—		126,313		—
Commercial mortgage-backed securities guaranteed by U.S. government agencies	2,911,946		—		2,911,946		—
Other debt securities	4,151		—		—		4,151
Perpetual preferred stock	17,931		—		17,931		—
Equity securities and mutual funds	18,814		3,785		15,029		—
Total available for sale securities	8,830,689		4,789		8,812,149		13,751
Fair value option securities:
U.S. Treasury	25,306		25,306		—		—
U.S. government agency residential mortgage-backed securities	237,959		—		237,959		—
Total fair value option securities	263,265		25,306		237,959		—
Residential mortgage loans held for sale	430,728		—		420,979		9,749
Mortgage servicing rights¹	190,747		—		—		190,747
Derivative contracts, net of cash collateral²	883,673		7,246		876,427		—
Liabilities:
Derivative contracts, net of cash collateral²	719,159		4,808		714,351		—


¹	A reconciliation of the beginning and ending fair value of mortgage servicing rights and disclosures of significant assumptions used to determine fair value are presented in Note 6, Mortgage Banking Activities.

See Note 3 for detail of fair value of derivative contracts by contract type. Derivative contracts based on quoted prices in active markets for identical instruments (Level 1) are exchange-traded energy and agricultural derivative contacts, net of cash margin. Derivative contracts in liability positions that were valued using quoted prices in active markets for identical instruments (Level 1) are exchange-traded interest rate and energy derivative contracts, net cash margin.

Fair Value Assets Measured On Recurring Basis, Significant Unobservable Inputs [Table Text Block]

The following represents the changes for the three and six months ended June 30, 2017 related to assets measured at fair value on a recurring basis using significant unobservable inputs (in thousands):



	Available for Sale Securities
	Municipal and other tax-exempt securities			Other debt securities			Residential mortgage loans held for sale
Balance, March 31, 2017	$	5,722		$	4,153		$	12,679
Transfer to Level 3 from Level 2¹	—			—			853
Purchases	—			—			—
Proceeds from sales	—			—			(1,030		)
Redemptions and distributions	(1,100		)	—			—
Gain (loss) recognized in earnings:
Mortgage banking revenue	—			—			233
Other comprehensive income (loss):
Net change in unrealized gain (loss)	33			(1		)	—
Balance, June 30, 2017	$	4,655		$	4,152		$	12,735


¹	Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards.



	Available for Sale Securities
	Municipal and other tax-exempt			Other debt securities		Residential mortgage loans held for sale
Balance, Dec. 31, 2016	$	5,789		$	4,152	$	11,617
Transfer to Level 3 from Level 2¹	—			—		2,740
Purchases	—			—		—
Proceeds from sales	—			—		(1,702		)
Redemptions and distributions	(1,100		)	—		—
Gain (loss) recognized in earnings:
Mortgage banking revenue	—			—		80
Other comprehensive income (loss):
Net change in unrealized gain (loss)	(34		)	—		—
Balance, June 30, 2017	$	4,655		$	4,152	$	12,735


¹	Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards.

The following represents the changes for the three and six months ended June 30, 2016 related to assets measured at fair value on a recurring basis using significant unobservable inputs (in thousands):



	Available for Sale Securities
	Municipal and other tax-exempt securities			Other debt securities		Residential mortgage loans held for sale
Balance, March 31, 2016	$	9,614		$	4,151	$	8,099
Transfer to Level 3 from Level 2¹	—			—		3,080
Purchases	—			—		—
Proceeds from sales	—			—		(1,249		)
Redemptions and distributions	—			—		—
Gain (loss) recognized in earnings:
Mortgage banking revenue	—			—		(181		)
Other comprehensive income (loss):
Net change in unrealized gain (loss)	(14		)	—		—
Balance, June 30, 2016	$	9,600		$	4,151	$	9,749


¹	Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards.



	Available for Sale Securities
	Municipal and other tax-exempt			Other debt securities		Residential mortgage loans held for sale
Balance, Dec. 31, 2015	$	9,610		$	4,151	$	7,874
Transfer to Level 3 from Level 2¹	—			—		3,540
Purchases	—			—		—
Proceeds from sales	—			—		(1,362		)
Redemptions and distributions	—			—		—
Gain (loss) recognized in earnings
Mortgage banking revenue	—			—		(303		)
Other comprehensive income (loss):
Net change in unrealized gain (loss)	(10		)	—		—
Balance, June 30, 2016	$	9,600		$	4,151	$	9,749


¹	Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards.

Fair Value Inputs, Fair Value Measured On a Recurring Basis, Quantitative Information [Table Text Block]

A summary of quantitative information about assets measured at fair value on a recurring basis using Significant Unobservable Inputs (Level 3) as of June 30, 2017 follows (in thousands):



	Par Value		Amortized Cost/Unpaid Principal Balance		Fair Value		Valuation Technique(s)		Unobservable Input	Range (Weighted Average)

Available for sale securities
Municipal and other tax-exempt securities	$	5,095	$	5,067	$	4,655	Discounted cash flows	¹	Interest rate spread	5.98%-5.98% (5.98%)	²
										90.00%-94.90% (92.93%)	³
Other debt securities	4,400		4,400		4,152		Discounted cash flows	¹	Interest rate spread	5.41%-6.72% (6.57%)	⁴
										94.31% - 94.38 (94.37%)	³

Residential mortgage loans held for sale	N/A		13,274		12,563		Quoted prices of loans sold in securitization transactions, with a liquidity discount applied		Liquidity discount applied to the market value of a mortgage loans qualifying for sale to U.S. government agencies.	94.64%


¹	Discounted cash flows developed using discount rates primarily based on reference to interest rate spreads for comparable securities of similar duration and credit rating as determined by the nationally-recognized rating agencies, adjusted for lack of trading volume.


²	Interest rate yields used to value investment grade tax-exempt securities represent a spread of 360 to 446 basis points over average yields for comparable tax-exempt securities.


³	Represents fair value as a percentage of par value.


⁴	Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 3 percent.

A summary of quantitative information about Recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of December 31, 2016 follows (in thousands):



	Par Value		Amortized Cost/Unpaid Principal Balance		Fair Value		Valuation Technique(s)		Unobservable Input	Range (Weighted Average)

Available for sale securities
Municipal and other tax-exempt securities	$	6,195	$	6,163	$	5,789	Discounted cash flows	¹	Interest rate spread	5.91%-6.21% (6.16%)	²
										90.00%-93.40% (92.20%)	³
Other debt securities	4,400		4,400		4,152		Discounted cash flows	¹	Interest rate spread	6.01%-6.26% (6.23%)	⁴
										94.34% - 94.36 (94.36%)	³
Residential mortgage loans held for sale	N/A		12,431		11,617		Quoted prices of loans sold in securitization transactions, with a liquidity discount applied		Liquidity discount applied to the market value of a mortgage loans qualifying for sale to U.S. government agencies.	93.45%


¹	Discounted cash flows developed using discount rates primarily based on reference to interest rate spreads for comparable securities of similar duration and credit rating as determined by the nationally-recognized rating agencies, adjusted for lack of trading volume.


²	Interest rate yields used to value investment grade tax-exempt securities represent a spread of 467 to 525 basis points over average yields for comparable tax-exempt securities.


³	Represents fair value as a percentage of par value.


⁴	Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 1 percent.

A summary of quantitative information about Recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of June 30, 2016 follows (in thousands):



	Par Value		Amortized Cost		Fair Value		Valuation Technique(s)		Unobservable Input	Range (Weighted Average)

Available for sale securities
Municipal and other tax-exempt securities	$	10,370	$	10,312	$	9,600	Discounted cash flows	¹	Interest rate spread	5.34%-5.64% (5.60%)	²
										90.00%-93.28% (92.58%)	³
Other debt securities	4,400		4,400		4,151		Discounted cash flows	¹	Interest rate spread	5.51%-5.96% (5.91%)	⁴
										94.32% - 94.34 (94.34%)	³

Residential mortgage loans held for sale	N/A		10,518		9,749		Quoted prices of loans sold in securitization transactions, with a liquidity discount applied		Liquidity discount applied to the market value of a mortgage loans qualifying for sale to U.S. government agencies.	92.69%


¹	Discounted cash flows developed using discount rates primarily based on reference to interest rate spreads for comparable securities of similar duration and credit rating as determined by the nationally-recognized rating agencies, adjusted for lack of trading volume.


²	Interest rate yields used to value investment grade tax-exempt securities represent a spread of 474 to 513 basis points over average yields for comparable tax-exempt securities.


³	Represents fair value as a percentage of par value.


⁴	Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 1 percent.

Fair Value Assets Measured on Nonrecurring Basis [Table Text Block]

The following represents the carrying value of assets measured at fair value on a non-recurring basis (and related losses) during the period. The carrying value represents only those assets with a balance at June 30, 2017 for which the fair value was adjusted during the six months ended June 30, 2017:



							Fair Value Adjustments for the
	Carrying Value at June 30, 2017						Three Months Ended June 30, 2017 Recognized in:				Six Months Ended June 30, 2017 Recognized in:
	Quoted Prices in Active Markets for Identical Instruments		Significant Other Observable Inputs		Significant Unobservable Inputs		Gross charge-offs against allowance for loan losses		Net losses and expenses of repossessed assets, net		Gross charge-offs against allowance for loan losses		Net losses and expenses of repossessed assets, net
Impaired loans	$	—	$	464	$	3,570	$	232	$	—	$	676	$	—
Real estate and other repossessed assets	—		3,488		530		—		772		—		906

The following represents the carrying value of assets measured at fair value on a non-recurring basis (and related losses) during the period. The carrying value represents only those assets with a balance at June 30, 2016 for which the fair value was adjusted during the six months ended June 30, 2016:



	Carrying Value at June 30, 2016						Fair Value Adjustments for the Three Months Ended June 30, 2016 Recognized in:				Six Months Ended June 30, 2016 Recognized in:
	Quoted Prices in Active Markets for Identical Instruments		Significant Other Observable Inputs		Significant Unobservable Inputs		Gross charge-offs against allowance for loan losses		Net losses and expenses of repossessed assets, net		Gross charge-offs against allowance for loan losses		Net losses and expenses of repossessed assets, net
Impaired loans	$	—	$	634	$	42,342	$	7,041	$	—	$	29,186	$	—
Real estate and other repossessed assets	—		5,709		1,693		—		751		—		1,068

Fair Value Inputs, Fair Value Measured On a Nonrecurring Basis, Quantitative Information [Table Text Block]

A summary of quantitative information about Non-recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of June 30, 2017 follows (in thousands):



	Fair Value		Valuation Technique(s)	Unobservable Input	Range (Weighted Average)
Impaired loans	$	3,570	Discounted cash flows	Recoverable oil and gas reserves, forward-looking commodity prices, estimated operating costs	75% - 90% (83%)¹
Real estate and other repossessed assets	530		Appraised value, as adjusted	Marketability adjustment off appraised value²	65% - 88% (80%)


¹	Represents fair value as a percentage of the unpaid principal balance.


²	Marketability adjustments include consideration of estimated costs to sell which is approximately 10% of the fair value.

A summary of quantitative information about Non-recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of June 30, 2016 follows (in thousands):



	Fair Value		Valuation Technique(s)	Unobservable Input	Range (Weighted Average)
Impaired loans	$	42,342	Discounted cash flows	Recoverable oil and gas reserves, forward-looking commodity prices, estimated operating costs	25% - 71% (58%)¹
Real estate and other repossessed assets	1,693		Appraised value, as adjusted	Marketability adjustments off appraised value2	68% - 80% (71%)


¹	Represents fair value as a percentage of the unpaid principal balance.


²	Marketability adjustments include consideration of estimated costs to sell which is approximately 10% of the fair value.

Fair Value of Financial Instruments [Table Text Block]

The following table presents the carrying values and estimated fair values of all financial instruments, including those financial assets and liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis as of June 30, 2017 (dollars in thousands):



	Carrying Value			Estimated Fair Value		Quoted Prices in Active Markets for Identical Instruments (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash and due from banks	$	561,587		$	561,587	$	561,587	$	—	$	—
Interest-bearing cash and cash equivalents	2,078,831			2,078,831		2,078,831		—		—
Trading securities:								—
U.S. government agency debentures	20,954			20,954		—		20,954		—
U.S. government agency residential mortgage-backed securities	365,171			365,171		—		365,171		—
Municipal and other tax-exempt securities	45,444			45,444		—		45,444		—
Other trading securities	9,845			9,845		—		9,845		—
Total trading securities	441,414			441,414		—		441,414		—
Investment securities:
Municipal and other tax-exempt securities	267,375			270,531		—		270,531		—
U.S. government agency residential mortgage-backed securities	18,035			18,642		—		18,642		—
Other debt securities	205,016			226,502		—		226,502		—
Total investment securities	490,426			515,675		—		515,675		—
Available for sale securities:
U.S. Treasury	998			998		998		—		—
Municipal and other tax-exempt securities	32,765			32,765		—		28,110		4,655
U.S. government agency residential mortgage-backed securities	5,382,377			5,382,377		—		5,382,377		—
Privately issued residential mortgage-backed securities	103,383			103,383		—		103,383		—
Commercial mortgage-backed securities guaranteed by U.S. government agencies	2,782,070			2,782,070		—		2,782,070		—
Other debt securities	4,152			4,152		—		—		4,152
Perpetual preferred stock	16,568			16,568		—		16,568		—
Equity securities and mutual funds	18,728			18,728		3,516		15,212		—
Total available for sale securities	8,341,041			8,341,041		4,514		8,327,720		8,807
Fair value option securities – U.S. government agency residential mortgage-backed securities	445,169			445,169		—		445,169		—
Residential mortgage loans held for sale	287,259			287,259		—		274,524		12,735
Loans:
Commercial	10,637,955			10,413,704		—		—		10,413,704
Commercial real estate	3,688,592			3,636,365		—		—		3,636,365
Residential mortgage	1,939,198			1,950,577		—		—		1,950,577
Personal	917,900			909,055		—		—		909,055
Total loans	17,183,645			16,909,701		—		—		16,909,701
Allowance for loan losses	(250,061		)	—		—		—		—
Loans, net of allowance	16,933,584			16,909,701		—		—		16,909,701
Mortgage servicing rights	245,239			245,239		—		—		245,239
Derivative instruments with positive fair value, net of cash collateral	280,289			280,289		46,366		233,923		—
Deposits with no stated maturity	20,120,352			20,120,352		—		—		20,120,352
Time deposits	2,196,122			2,164,115		—		—		2,164,115
Other borrowed funds	5,696,666			5,664,273		—		—		5,664,273
Subordinated debentures	144,658			147,204		—		147,204		—
Derivative instruments with negative fair value, net of cash collateral	285,819			285,819		20,915		264,904		—



	Carrying Value			Estimated Fair Value		Quoted Prices in Active Markets for Identical Instruments (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash and due from banks	$	620,846		$	620,846	$	620,846	$	—	$	—
Interest-bearing cash and cash equivalents	1,916,651			1,916,651		1,916,651		—		—
Trading securities:								—
U.S. government agency debentures	6,234			6,234		—		6,234		—
U.S. government agency residential mortgage-backed securities	310,067			310,067		—		310,067		—
Municipal and other tax-exempt securities	14,427			14,427		—		14,427		—
Other trading securities	6,900			6,900		—		6,900		—
Total trading securities	337,628			337,628		—		337,628		—
Investment securities:
Municipal and other tax-exempt securities	320,364			321,225		—		321,225		—
U.S. government agency residential mortgage-backed securities	20,777			21,473		—		21,473		—
Other debt securities	205,004			222,795		—		222,795		—
Total investment securities	546,145			565,493		—		565,493		—
Available for sale securities:
U.S. Treasury	999			999		999		—		—
Municipal and other tax-exempt securities	40,993			40,993		—		35,204		5,789
U.S. government agency residential mortgage-backed securities	5,460,386			5,460,386		—		5,460,386		—
Privately issued residential mortgage-backed securities	115,535			115,535		—		115,535		—
Commercial mortgage-backed securities guaranteed by U.S. government agencies	3,017,933			3,017,933		—		3,017,933		—
Other debt securities	4,152			4,152		—		—		4,152
Perpetual preferred stock	18,474			18,474		—		18,474		—
Equity securities and mutual funds	18,357			18,357		3,495		14,862		—
Total available for sale securities	8,676,829			8,676,829		4,494		8,662,394		9,941
Fair value option securities – U.S. government agency residential mortgage-backed securities	77,046			77,046		—		77,046		—
Residential mortgage loans held for sale	301,897			301,897		—		290,280		11,617
Loans:
Commercial	10,390,824			10,437,016		—		—		10,437,016
Commercial real estate	3,809,046			3,850,981		—		—		3,850,981
Residential mortgage	1,949,832			2,025,159		—		—		2,025,159
Personal	839,958			864,904		—		—		864,904
Total loans	16,989,660			17,178,060		—		—		17,178,060
Allowance for loan losses	(246,159		)	—		—		—		—
Loans, net of allowance	16,743,501			17,178,060		—		—		17,178,060
Mortgage servicing rights	247,073			247,073		—		—		247,073
Derivative instruments with positive fair value, net of cash collateral	689,872			689,872		7,541		682,331		—
Deposits with no stated maturity	20,526,295			20,526,295		—		—		20,526,295
Time deposits	2,221,800			2,218,303		—		—		2,218,303
Other borrowed funds	5,572,662			5,556,327		—		—		5,556,327
Subordinated debentures	144,640			128,903		—		128,903		—
Derivative instruments with negative fair value, net of cash collateral	664,531			664,531		6,972		657,559		—



	Carrying Value			Estimated Fair Value		Quoted Prices in Active Markets for Identical Instruments (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash and due from banks	$	498,713		$	498,713	$	498,713	$	—	$	—
Interest-bearing cash and cash equivalents	1,907,838			1,907,838		1,907,838		—		—
Trading securities:								—
U.S. government agency debentures	18,909			18,909		—		18,909		—
U.S. government agency residential mortgage-backed securities	122,306			122,306		—		122,306		—
Municipal and other tax-exempt securities	52,721			52,721		—		52,721		—
Other trading securities	17,686			17,686		—		17,686		—
Total trading securities	211,622			211,622		—		211,622		—
Investment securities:
Municipal and other tax-exempt securities	334,551			340,700		—		340,700		—
U.S. government agency residential mortgage-backed securities	23,750			25,233		—		25,233		—
Other debt securities	202,410			233,129		—		233,129		—
Total investment securities	560,711			599,062		—		599,062		—
Available for sale securities:
U.S. Treasury	1,004			1,004		1,004		—		—
Municipal and other tax-exempt securities	50,262			50,262		—		40,662		9,600
U.S. government agency residential mortgage-backed securities	5,700,268			5,700,268		—		5,700,268		—
Privately issued residential mortgage-backed securities	126,313			126,313		—		126,313		—
Commercial mortgage-backed securities guaranteed by U.S. government agencies	2,911,946			2,911,946		—		2,911,946		—
Other debt securities	4,151			4,151		—		—		4,151
Perpetual preferred stock	17,931			17,931		—		17,931		—
Equity securities and mutual funds	18,814			18,814		3,785		15,029		—
Total available for sale securities	8,830,689			8,830,689		4,789		8,812,149		13,751
Fair value option securities:
U.S. Treasury	25,306			25,306		25,306		—		—
U.S. government agency residential mortgage-backed securities	237,959			237,959		—		237,959		—
Total fair value option securities	263,265			263,265		25,306		237,959		—
Residential mortgage loans held for sale	430,728			430,728		—		420,979		9,749
Loans:
Commercial	10,356,437			10,172,701		—		—		10,172,701
Commercial real estate	3,581,966			3,563,378		—		—		3,563,378
Residential mortgage	1,880,923			1,913,208		—		—		1,913,208
Personal	587,423			582,353		—		—		582,353
Total loans	16,406,749			16,231,640		—		—		16,231,640
Allowance for loan losses	(243,259		)	—		—		—		—
Loans, net of allowance	16,163,490			16,231,640		—		—		16,231,640
Mortgage servicing rights	190,747			190,747		—		—		190,747
Derivative instruments with positive fair value, net of cash collateral	883,673			883,673		7,246		876,427		—
Deposits with no stated maturity	18,512,740			18,512,740		—		—		18,512,740
Time deposits	2,247,061			2,252,212		—		—		2,252,212
Other borrowed funds	6,360,199			6,342,885		—		—		6,342,885
Subordinated debentures	371,812			371,808		—		150,234		221,574
Derivative instruments with negative fair value, net of cash collateral	719,159			719,159		4,808		714,351		—

Fair Value Inputs, Financial Instruments, Quantitative Information [Table Text Block]



	Range of Contractual Yields				Average Re-pricing (in years)	Discount Rate
	Minimum		Maximum		Average	Minimum		Maximum
June 30, 2017
Commercial	0.38	%	30.00	%	0.64	0.71	%	4.56	%
Commercial real estate	0.38	%	18.00	%	0.77	1.03	%	4.31	%
Residential mortgage	1.74	%	18.00	%	2.18	1.75	%	4.19	%
Consumer	0.25	%	21.00	%	0.28	0.70	%	4.68	%

Time deposits	0.03	%	10.00	%	1.91	1.81	%	2.12	%
Other borrowings	0.25	%	3.58	%	0.02	1.06	%	3.69	%
Subordinated debentures	5.38	%	5.38	%	16.90	4.89	%	4.89	%

December 31, 2016
Commercial	0.38	%	30.00	%	0.70	0.64	%	4.60	%
Commercial real estate	0.38	%	18.00	%	0.71	0.94	%	4.27	%
Residential mortgage	1.74	%	18.00	%	2.27	1.71	%	4.26	%
Consumer	0.25	%	21.00	%	0.40	1.03	%	4.59	%

Time deposits	0.02	%	9.65	%	1.96	1.57	%	2.00	%
Other borrowings	0.25	%	3.50	%	0.00	0.55	%	3.22	%
Subordinated debentures	5.38	%	5.38	%	16.86	6.11	%	6.11	%

June 30, 2016
Commercial	0.38	%	30.00	%	0.69	0.55	%	3.68	%
Commercial real estate	0.38	%	18.00	%	0.73	0.80	%	3.65	%
Residential mortgage	1.70	%	18.00	%	1.97	1.25	%	3.75	%
Consumer	0.25	%	21.00	%	0.35	0.71	%	3.91	%

Time deposits	0.03	%	9.64	%	2.15	1.16	%	1.43	%
Other borrowings	0.25	%	3.28	%	0.02	0.30	%	2.92	%
Subordinated debentures	1.32	%	5.38	%	8.35	2.16	%	5.38	%