Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2016

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

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



	Total		Quoted Prices in Active Markets for Identical Instruments		Significant Other Observable Inputs		Significant Unobservable Inputs
Assets:
Trading securities:
U.S. government agency debentures	$	6,234	$	—	$	6,234	$	—
U.S. 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 securities	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 rights, net¹	247,073		—		—		247,073
Derivative contracts, net of cash margin²	689,872		7,541		682,331		—
Liabilities:
Derivative contracts, net of cash margin²	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 7, Mortgage Banking Activities.

See Note 3 for detail of fair value of derivative contracts by contract type. Derivative contracts in a net asset position that were valued based on quoted prices in active markets or identical instruments (Level 1) are exchange-traded interest rate and energy derivative contracts, net of cash margin. Derivative contracts in a net liability position 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 that are measured on a recurring basis is as follows as of December 31, 2015 (in thousands):



	Total		Quoted Prices in Active Markets for Identical Instruments		Significant Other Observable Inputs		Significant Unobservable Inputs
Assets:
Trading securities:
U.S. government agency debentures	$	61,295	$	—	$	61,295	$	—
U.S. government agency residential mortgage-backed securities	10,989		—		10,989		—
Municipal and other tax-exempt securities	31,901		—		31,901		—
Other trading securities	18,219		—		18,219		—
Total trading securities	122,404		—		122,404		—
Available for sale securities:
U.S. Treasury securities	995		995		—		—
Municipal and other tax-exempt securities	56,817		—		47,207		9,610
U.S. government agency residential mortgage-backed securities	5,898,351		—		5,898,351		—
Privately issued residential mortgage-backed securities	139,118		—		139,118		—
Commercial mortgage-backed securities guaranteed by U.S. government agencies	2,905,796		—		2,905,796		—
Other debt securities	4,151		—		—		4,151
Perpetual preferred stock	19,672		—		19,672		—
Equity securities and mutual funds	17,833		3,265		14,568		—
Total available for sale securities	9,042,733		4,260		9,024,712		13,761
Fair value option securities – U.S. government agency residential mortgage-backed securities	444,217		—		444,217		—
Residential mortgage loans held for sale	308,439		—		300,565		7,874
Mortgage servicing rights, net¹	218,605		—		—		218,605
Derivative contracts, net of cash margin²	586,270		38,530		547,740		—
Liabilities:
Derivative contracts, net of cash margin ²	581,701		—		581,701		—


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 7, Mortgage Banking Activities.

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

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

The following represents the changes related to assets measured at fair value on a recurring basis using significant unobservable inputs (in thousands):



	Available for Sale Securities					Residential mortgage loans held for sale
	Municipal and other tax-exempt securities			Other debt securities		Residential mortgage loans held for sale
Balance, December 31, 2014	$	10,093		$	4,150	$	11,856
Transfer to Level 3 from Level 2¹	—			—		2,193
Purchases and capital calls	—			—		—
Redemptions and distributions	—			—		—
Proceeds from sales	—			—		(6,283		)
Gain (loss) recognized in earnings:
Mortgage banking revenue	—			—		108
Other comprehensive income (loss):
Net change in unrealized gain (loss)	(483		)	1		—
Balance, December 31, 2015	9,610			4,151		7,874
Transfer to Level 3 from Level 2¹	—			—		6,631
Purchases and capital calls	—			—		—
Redemptions and distributions	(3,975		)	—		—
Proceeds from sales	—			—		(2,540		)
Gain (loss) recognized in earnings:
Mortgage banking revenue	—			—		(348		)
Other comprehensive income (loss):
Net change in unrealized gain (loss)	154			1		—
Balance, December 31, 2016	$	5,789		$	4,152	$	11,617

Fair Value Inputs, Assets, 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 December 31, 2016 follows (in thousands):



Quantitative Information about Level 3 Non-recurring Fair Value Measurements
	Fair Value		Valuation Technique(s)	Significant Unobservable Input	Range (Weighted Average)

Impaired loans	$	11,295	Appraised value, as adjusted	Recoverable oil and gas reserves, forward-looking commodity prices and estimated operating costs	22% - 59% (57%)¹
Real estate and other repossessed assets	2,192		Appraised value, as adjusted	Marketability adjustments off appraised value²	70% - 87% (74%)


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 December 31, 2015 follows (in thousands):



Quantitative Information about Level 3 Non-recurring Fair Value Measurements
	Fair Value		Valuation Technique(s)	Significant Unobservable Input	Range (Weighted Average)

Impaired loans	$	20,805	Appraised value, as adjusted	Broker quotes and management's knowledge of industry and collateral.	N/A
Real estate and other repossessed assets	245		Appraised value, as adjusted	Marketability adjustments off appraised value¹	66%-81% (74%)


¹	Marketability adjustments include consideration of estimated costs to sell which is approximately 10% of the fair value.

A summary of quantitative information about assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3) as of December 31, 2016 follows (in thousands):



Quantitative Information about Level 3 Recurring Fair Value Measurements
	Par Value		Amortized Cost/Unpaid Principal Balance		Fair Value		Valuation Technique(s)		Significant Unobservable Input	Range (Weighted Average)

Available for sale securities:
Municipal and other tax-exempt securities	$	6,195	$	6,163	$	5,712	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 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 approximately 1%.

A summary of quantitative information about Recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of December 31, 2015 follows (in thousands):



Quantitative Information about Level 3 Recurring Fair Value Measurements
	Par Value		Amortized Cost⁶		Fair Value		Valuation Technique(s)		Significant Unobservable Input	Range (Weighted Average)

Available for sale securities:
Municipal and other tax-exempt securities	$	10,370	$	10,311	$	9,610	Discounted cash flows	¹	Interest rate spread	5.47%-5.77% (5.73%)	²
										92.34%-92.93% (92.67%)	³
Other debt securities	4,400		4,400		4,151		Discounted cash flows	¹	Interest rate spread	5.80% - 5.92% (5.90%)	⁴
										94.33% - 94.34% (94.34%)	³
Residential mortgage loans held for sale	N/A		8,395		7,874		Quoted prices of loans sold in securitization transactions, with a liquidity discount applied		Liquidity discount applied to the market value of mortgage loans qualifying for sale to U.S. government agencies	93.79%


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 499 to 541 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%.

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 recorded during the year. The carrying value represents only those assets with the balance sheet date for which the fair value was adjusted during the year:



	Carrying Value at December 31, 2016						Fair Value Adjustments for the Year Ended December 31, 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
Impaired loans	$	—	$	539	$	11,295	$	7,594	$	—
Real estate and other repossessed assets	—		7,965		2,192		—		2,527



	Carrying Value at December 31, 2015						Fair Value Adjustments for the Year Ended December 31, 2015 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
Impaired loans	$	—	$	252	$	20,805	$	4,042	$	—
Real estate and other repossessed assets	—		13,611		245		—		1,820

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 (dollars in thousands):



	December 31, 2016
	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 securities	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 margin	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 margin	664,531			664,531	6,972	657,559	—



	December 31, 2015
	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	$	573,699		$	573,699	573,699	—	$	—
Interest-bearing cash and cash equivalents	2,069,900			2,069,900		2,069,900	—	—
Trading securities:
U.S. government agency debentures	61,295			61,295		—	61,295	—
U.S. government agency residential mortgage-backed securities	10,989			10,989		—	10,989	—
Municipal and other tax-exempt securities	31,901			31,901		—	31,901	—
Other trading securities	18,219			18,219		—	18,219	—
Total trading securities	122,404			122,404		—	122,404	—
Investment securities:
Municipal and other tax-exempt securities	365,258			368,910		—	368,910	—
U.S. government agency residential mortgage-backed securities	26,833			27,874		—	27,874	—
Other debt securities	205,745			232,375		—	232,375	—
Total investment securities	597,836			629,159		—	629,159	—
Available for sale securities:
U.S. Treasury securities	995			995		995	—	—
Municipal and other tax-exempt securities	56,817			56,817		—	47,207	9,610
U.S. government agency residential mortgage-backed securities	5,898,351			5,898,351		—	5,898,351	—
Privately issued residential mortgage-backed securities	139,118			139,118		—	139,118	—
Commercial mortgage-backed securities guaranteed by U.S. government agencies	2,905,796			2,905,796		—	2,905,796	—
Other debt securities	4,151			4,151		—	—	4,151
Perpetual preferred stock	19,672			19,672		—	19,672	—
Equity securities and mutual funds	17,833			17,833		3,265	14,568	—
Total available for sale securities	9,042,733			9,042,733		4,260	9,024,712	13,761
Fair value option securities – U.S. government agency residential mortgage-backed securities	444,217			444,217		—	444,217	—
Residential mortgage loans held for sale	308,439			308,439		—	300,565	7,874
Loans:
Commercial	10,252,531			10,053,952		—	—	10,053,952
Commercial real estate	3,259,033			3,233,476		—	—	3,233,476
Residential mortgage	1,876,893			1,902,976		—	—	1,902,976
Personal	552,697			549,068		—	—	549,068
Total loans	15,941,154			15,739,472		—	—	15,739,472
Allowance for loan losses	(225,524		)	—		—	—	—
Loans, net of allowance	15,715,630			15,739,472		—	—	15,739,472
Mortgage servicing rights	218,605			218,605		—	—	218,605
Derivative instruments with positive fair value, net of cash margin	586,270			586,270		38,530	547,740	—
Deposits with no stated maturity	18,682,094			18,682,094		—	—	18,682,094
Time deposits	2,406,064			2,394,562		—	—	2,394,562
Other borrowed funds	6,051,515			5,600,932		—	—	5,600,932
Subordinated debentures	226,350			223,758		—	—	223,758
Derivative instruments with negative fair value, net of cash margin	581,701			581,701		—	581,701	—

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



	Range of Contractual Yields				Average Re-pricing (in years)	Discount Rate
	Minimum		Maximum		Average Re-pricing (in years)	Minimum		Maximum
December 31, 2016
Loans:
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	%
Personal	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	5.38	%	5.38	%

December 31, 2015
Loans:
Commercial	0.25	%	30.00	%	0.62	0.52	%	4.34	%
Commercial real estate	0.38	%	18.00	%	0.73	0.95	%	3.93	%
Residential mortgage	1.67	%	18.00	%	2.42	0.86	%	4.25	%
Personal	0.38	%	21.00	%	0.37	1.19	%	4.11	%

Time deposits	0.02	%	5.50	%	1.78	1.11	%	1.57	%
Other borrowings	0.25	%	3.40	%	0.00	0.20	%	2.89	%
Subordinated debentures	1.05	%	1.05	%	1.37	2.12	%	2.12	%