Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2020

Fair Value Disclosures [Abstract]

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, 2020 (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	$	4,237	$	—	$	4,237	$	—
Residential agency mortgage-backed securities	1,146,454		—		1,146,454		—
Municipal and other tax-exempt securities	22,710		—		22,710		—
Asset-backed securities	5		—		5		—
Other trading securities	22,699		—		22,699		—
Total trading securities	1,196,105		—		1,196,105		—
Available for sale securities:
U.S. Treasury	912		912		—		—
Municipal and other tax-exempt securities	31,240		—		31,240		—
Residential agency mortgage-backed securities	9,147,238		—		9,147,238		—
Residential non-agency mortgage-backed securities	35,250		—		35,250		—
Commercial agency mortgage-backed securities	3,260,807		—		3,260,807		—
Other debt securities	472		—		—		472
Total available for sale securities	12,475,919		912		12,474,535		472
Fair value option securities:
U.S. Treasury	92,742		92,742		—		—
Residential agency mortgage-backed securities	629,915		—		629,915		—
Total fair value option securities	722,657		92,742		629,915		—
Residential mortgage loans held for sale	319,357		—		309,672		9,685
Mortgage servicing rights1	97,971		—		—		97,971
Derivative contracts, net of cash collateral2	651,553		66,207		585,346		—
Liabilities:
Derivative contracts, net of cash collateral2	610,020		—		610,020		—

¹A 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 5, Mortgage Banking Activities.

²See 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, net of cash margin. 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, fully offset by cash margin.

The fair value of financial assets and liabilities measured on a recurring basis was as follows as of December 31, 2019 (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	$	44,264	$	—	$	44,264	$	—
Residential agency mortgage-backed securities	1,504,651		—		1,504,651		—
Municipal and other tax-exempt securities	26,196		—		26,196		—
Asset-backed securities	14,084		—		14,084		—
Other trading securities	34,726		—		34,726		—
Total trading securities	1,623,921		—		1,623,921		—
Available for sale securities:
U.S. Treasury	1,600		1,600		—		—
Municipal and other tax-exempt securities	1,861		—		1,861		—
Residential agency mortgage-backed securities	8,046,096		—		8,046,096		—
Residential non-agency mortgage-backed securities	41,609		—		41,609		—
Commercial agency mortgage-backed securities	3,178,005		—		3,178,005		—
Other debt securities	472		—		—		472
Total available for sale securities	11,269,643		1,600		11,267,571		472
Fair value option securities:
U.S. Treasury	9,917		9,917		—		—
Residential agency mortgage-backed securities	1,088,660		—		1,088,660		—
Total fair value option securities	1,098,577		9,917		1,088,660		—
Residential mortgage loans held for sale	182,271		—		173,958		8,313
Mortgage servicing rights1	201,886		—		—		201,886
Derivative contracts, net of cash collateral2	323,375		8,944		314,431		—
Liabilities:
Derivative contracts, net of cash collateral2	251,128		—		251,128		—

¹A 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 5, Mortgage Banking Activities.

²See 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 and agricultural contracts, fully offset by 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, 2020 related to assets measured at fair value on a recurring basis using significant unobservable inputs (in thousands):

	Available for sale - Other debt securities		Residential mortgage loans held for sale
Balance, Mar. 31, 2020	$	472	$	9,574
Transfer to Level 3 from Level 21	—		1,328
Purchases	—		—
Proceeds from sales	—		(648)
Redemptions and distributions	—		—
Gain (loss) recognized in earnings:
Mortgage banking revenue	—		(569)
Other comprehensive income (loss):
Net change in unrealized gain (loss)	—		—
Balance, June 30, 2020	$	472	$	9,685

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 - Other debt securities		Residential mortgage loans held for sale
Balance, December 31, 2019	$	472	$	8,313
Transfer to Level 3 from Level 21	—		3,592
Purchases	—		—
Proceeds from sales	—		(1,588)
Redemptions and distributions	—		—
Gain (loss) recognized in earnings:
Mortgage banking revenue	—		(632)
Other comprehensive income (loss):
Net change in unrealized gain (loss)	—		—
Balance, June 30, 2020	$	472	$	9,685

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, 2019 related to assets measured at fair value on a recurring basis using significant unobservable inputs (in thousands):

	Available for sale - Other debt securities		Residential mortgage loans held for sale
Balance, Mar. 31, 2019	$	472	$	15,776
Transfer to Level 3 from Level 21	—		907
Purchases	—		—
Proceeds from sales	—		(998)
Redemptions and distributions	—		—
Gain (loss) recognized in earnings:
Mortgage banking revenue	—		388
Other comprehensive income (loss):
Net change in unrealized gain (loss)	—		—
Balance, June 30, 2019	$	472	$	16,073

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 - Other debt securities		Residential mortgage loans held for sale
Balance, Dec. 31, 2018	$	472	$	15,207
Transfer to Level 3 from Level 21	—		1,889
Purchases	—		—
Proceeds from sales	—		(1,379)
Redemptions and distributions	—		—
Gain (loss) recognized in earnings
Mortgage banking revenue	—		356
Other comprehensive income (loss):
Net change in unrealized gain (loss)	—		—
Balance, June 30, 2019	$	472	$	16,073

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, 2020 follows (in thousands):

	Fair Value		Valuation Technique(s)		Unobservable Input	Range (Weighted Average)
Available for sale securities – Other debt securities	$	472	Discounted cash flows	1	Interest rate spread	5.23%-5.23% (5.23%)	3
						94.30%-94.30% (94.30%)	2
Residential mortgage loans held for sale	9,685		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.	90.24%

¹Discounted 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.

²Represents fair value as a percentage of par value.

³Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding approximately 1 percent.

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, 2019 follows (in thousands):

	Fair Value		Valuation Technique(s)		Unobservable Input	Range (Weighted Average)
Available for sale securities – Other debt securities	$	472	Discounted cash flows	1	Interest rate spread	7.08%-7.08% (7.08%)	3
						94.40%-94.40% (94.40%)	2
Residential mortgage loans held for sale	8,313		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.	95.23%

¹Discounted 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

²Represents fair value as a percentage of par value.

3Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 3 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, 2020 for which the fair value was adjusted during the six months ended June 30, 2020:

							Fair Value Adjustments for the
	Carrying Value at June 30, 2020						Three Months Ended June 30, 2020 Recognized in:				Six Months Ended June 30, 2020 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 operating expenses of repossessed assets		Gross charge-offs against allowance for loan losses		Net losses (gains) and operating expenses of repossessed assets
Nonaccruing loans	$	—	$	400	$	32,448	$	13,871	$	—	$	29,659	$	—
Real estate and other repossessed assets	—		918		400		—		5		—		131

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, 2019 for which the fair value was adjusted during the six months ended June 30, 2019:

							Fair Value Adjustments for the
	Carrying Value at June 30, 2019						Three Months Ended June 30, 2019 Recognized in:				Six Months Ended June 30, 2019 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 operating expenses of repossessed assets		Gross charge-offs against allowance for loan losses		Net losses and operating expenses of repossessed assets
Nonaccruing loans	$	—	$	—	$	29,187	$	11,335	$	—	$	20,917	$	—
Real estate and other repossessed assets	—		2,642		427		—		86		—		512

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, 2020 follows (in thousands):

	Fair Value		Valuation Technique(s)	Unobservable Input	Range (Weighted Average)
Nonaccruing loans	$	32,448	Discounted cash flows	Management knowledge of industry and non-real estate collateral including but not limited to recoverable oil and gas reserves, forward-looking commodity prices, estimated operating costs	0% - 83% (35%)1
Real estate and other repossessed assets	400		Appraised value, as adjusted	Marketability adjustments off appraised value2	87% - 87% (87%)

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, 2019 follows (in thousands):

	Fair Value		Valuation Technique(s)	Unobservable Input	Range (Weighted Average)
Nonaccruing loans	$	29,187	Discounted cash flows	Management knowledge of industry and non-real estate collateral including but not limited to recoverable oil and gas reserves, forward-looking commodity prices, estimated operating costs	12% - 76% (47%)1
Real estate and other repossessed assets	427		Appraised value, as adjusted	Marketability adjustments off appraised value2	75% - 89% (88%)

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, 2020 (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	$	762,453	$	762,453	$	762,453	$	—	$	—
Interest-bearing cash and cash equivalents	485,319		485,319		485,319		—		—
Trading securities:
U.S. government agency debentures	4,237		4,237		—		4,237		—
Residential agency mortgage-backed securities	1,146,454		1,146,454		—		1,146,454		—
Municipal and other tax-exempt securities	22,710		22,710		—		22,710		—
Asset-backed securities	5		5		—		5		—
Other trading securities	22,699		22,699		—		22,699		—
Total trading securities	1,196,105		1,196,105		—		1,196,105		—
Investment securities:
Municipal and other tax-exempt securities	84,239		88,623		—		88,623		—
Residential agency mortgage-backed securities	9,812		10,734		—		10,734		—
Other debt securities	175,565		199,769		—		8,048		191,721
Total investment securities	269,616		299,126		—		107,405		191,721
Allowance for credit losses	(1,628)		—		—		—		—
Investment securities, net of allowance	267,988		299,126		—		107,405		191,721
Available for sale securities:
U.S. Treasury	912		912		912		—		—
Municipal and other tax-exempt securities	31,240		31,240		—		31,240		—
Residential agency mortgage-backed securities	9,147,238		9,147,238		—		9,147,238		—
Residential non-agency mortgage-backed securities	35,250		35,250		—		35,250		—
Commercial agency mortgage-backed securities	3,260,807		3,260,807		—		3,260,807		—
Other debt securities	472		472		—		—		472
Total available for sale securities	12,475,919		12,475,919		912		12,474,535		472
Fair value option securities:
U.S. Treasury	92,742		92,742		92,742		—		—
Residential agency mortgage-backed securities	629,915		629,915		—		629,915		—
Total fair value option securities	722,657		722,657		92,742		629,915		—
Residential mortgage loans held for sale	319,357		319,357		—		309,672		9,685
Loans:
Commercial	14,158,510		14,038,257		—		—		14,038,257
Commercial real estate	4,554,144		4,558,274		—		—		4,558,274
Paycheck protection program	2,081,428		2,062,278		—		—		2,062,278
Loans to individuals	3,361,808		3,393,293		—		—		3,393,293
Total loans	24,155,890		24,052,102		—		—		24,052,102
Allowance for loan losses	(435,597)		—		—		—		—
Loans, net of allowance	23,720,293		24,052,102		—		—		24,052,102
Mortgage servicing rights	97,971		97,971		—		—		97,971
Derivative instruments with positive fair value, net of cash collateral	651,553		651,553		66,207		585,346		—
Deposits with no stated maturity	31,539,554		31,539,554		—		—		31,539,554
Time deposits	2,352,760		2,367,446		—		—		2,367,446
Other borrowed funds	4,531,165		4,527,814		—		—		4,527,814
Subordinated debentures	275,973		273,293		—		273,293		—
Derivative instruments with negative fair value, net of cash collateral	610,020		610,020		—		610,020		—

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 December 31, 2019 (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	$	735,836	$	735,836	$	735,836	$	—	$	—
Interest-bearing cash and cash equivalents	522,985		522,985		522,985		—		—
Trading securities:
U.S. government agency debentures	44,264		44,264		—		44,264		—
Residential agency mortgage-backed securities	1,504,651		1,504,651		—		1,504,651		—
Municipal and other tax-exempt securities	26,196		26,196		—		26,196		—
Asset-backed securities	14,084		14,084		—		14,084		—
Other trading securities	34,726		34,726		—		34,726		—
Total trading securities	1,623,921		1,623,921		—		1,623,921		—
Investment securities:
Municipal and other tax-exempt securities	93,653		96,897		—		96,897		—
Residential agency mortgage-backed securities	10,676		11,164		—		11,164		—
Other debt securities	189,089		206,341		—		8,206		198,135
Total investment securities	293,418		314,402		—		116,267		198,135
Available for sale securities:
U.S. Treasury	1,600		1,600		1,600		—		—
Municipal and other tax-exempt securities	1,861		1,861		—		1,861		—
Residential agency mortgage-backed securities	8,046,096		8,046,096		—		8,046,096		—
Residential non-agency mortgage-backed securities	41,609		41,609		—		41,609		—
Commercial agency mortgage-backed securities	3,178,005		3,178,005		—		3,178,005		—
Other debt securities	472		472		—		—		472
Total available for sale securities	11,269,643		11,269,643		1,600		11,267,571		472
Fair value option securities:
U.S. Treasury	9,917		9,917		9,917		—		—
Residential agency mortgage-backed securities	1,088,660		1,088,660		—		1,088,660		—
Total fair value option securities	1,098,577		1,098,577		9,917		1,088,660		—
Residential mortgage loans held for sale	182,271		182,271		—		173,958		8,313
Loans:
Commercial	14,031,650		13,966,221		—		—		13,966,221
Commercial real estate	4,433,783		4,422,717		—		—		4,422,717
Residential mortgage	2,084,172		2,098,093		—		—		2,098,093
Personal	1,201,382		1,202,298		—		—		1,202,298
Total loans	21,750,987		21,689,329		—		—		21,689,329
Allowance for loan losses	(210,759)		—		—		—		—
Loans, net of allowance	21,540,228		21,689,329		—		—		21,689,329
Mortgage servicing rights	201,886		201,886		—		—		201,886
Derivative instruments with positive fair value, net of cash collateral	323,375		323,375		8,944		314,431		—
Deposits with no stated maturity	25,403,319		25,403,319		—		—		25,403,319
Time deposits	2,217,849		2,212,467		—		—		2,212,467
Other borrowed funds	8,345,405		8,315,860		—		—		8,315,860
Subordinated debentures	275,923		284,627		—		284,627		—
Derivative instruments with negative fair value, net of cash collateral	251,128		251,128		—		251,128		—