Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2021

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 that are measured on a recurring basis is as follows as of December 31, 2021 (in thousands):

	Total		Quoted Prices in Active Markets for Identical Instruments		Significant Other Observable Inputs		Significant Unobservable Inputs
Assets:
Trading securities:
U.S. government securities	$	23,610	$	4,999	$	18,611	$	—
Residential agency mortgage-backed securities	9,068,900		—		9,068,900		—
Municipal securities	25,783		—		25,783		—
Other trading securities	18,520		—		18,520		—
Total trading securities	9,136,813		4,999		9,131,814		—
Available for sale securities:
U.S. Treasury	1,000		1,000		—		—
Municipal securities	508,365		—		508,365		—
Residential agency mortgage-backed securities	8,006,616		—		8,006,616		—
Residential non-agency mortgage-backed securities	24,339		—		24,339		—
Commercial agency mortgage-backed securities	4,617,025		—		4,617,025		—
Other debt securities	472		—		—		472
Total available for sale securities	13,157,817		1,000		13,156,345		472
Fair value option securities — Residential agency mortgage-backed securities	43,770		—		43,770		—
Residential mortgage loans held for sale1	192,295		—		185,969		6,326
Mortgage servicing rights, net2	163,198		—		—		163,198
Derivative contracts, net of cash margin3	1,097,297		8,331		1,088,966		—
Liabilities:
Derivative contracts, net of cash margin3	275,625		—		275,625		—

1Residential mortgage loans held for sale measured at fair value on a recurring basis using significant unobservable inputs (Level 3) consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards and are valued at 95.07% of the unpaid principal balance.

2A 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.

3See 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 interest rate derivative contracts. Derivative contracts in liability positions that were valued using quoted prices in active markets for identical instruments are exchange-traded energy derivative contracts, fully offset by cash margin.

The fair value of financial assets and liabilities that are measured on a recurring basis is as follows as of December 31, 2020 (in thousands):

	Total		Quoted Prices in Active Markets for Identical Instruments		Significant Other Observable Inputs		Significant Unobservable Inputs
Assets:
Trading securities:
U.S. government securities	$	9,183	$	4,999	$	4,184	$	—
Residential agency mortgage-backed securities	4,669,148		—		4,669,148		—
Municipal securities	19,172		—		19,172		—
Other trading securities	10,472		—		10,472		—
Total trading securities	4,707,975		4,999		4,702,976		—
Available for sale securities:
U.S. Treasury	508		508		—		—
Municipal securities	167,979		—		167,979		—
Residential agency mortgage-backed securities	9,340,471		—		9,340,471		—
Residential non-agency mortgage-backed securities	32,770		—		32,770		—
Commercial agency mortgage-backed securities	3,508,465		—		3,508,465		—
Other debt securities	472		—		—		472
Total available for sale securities	13,050,665		508		13,049,685		472
Fair value option securities — Residential agency mortgage-backed securities	114,982		—		114,982		—
Residential mortgage loans held for sale1	252,316		—		245,299		7,017
Mortgage servicing rights, net2	101,172		—		—		101,172
Derivative contracts, net of cash margin3	810,688		10,780		799,908		—
Liabilities:
Derivative contracts, net of cash margin3	405,779		—		405,779		—

1Residential mortgage loans held for sale measured at fair value on a recurring basis using significant unobservable inputs (Level 3) consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards and are valued at 94.57% of the unpaid principal balance.

2A 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.

3See 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 derivative contracts, 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 contracts, fully offset by cash margin.

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, 2021						Fair Value Adjustments for the Year Ended December 31, 2021 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		Other gains (losses), net
Nonaccruing loans	$	—	$	808	$	1,990	$	2,087	$	—
Real estate and other repossessed assets	—		1,706		—		—		(150)

	Carrying Value at December 31, 2020						Fair Value Adjustments for the Year Ended December 31, 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		Other gains (losses), net
Nonaccruing loans	$	—	$	801	$	20,423	$	39,299	$	—
Real estate and other repossessed assets	—		18,188		2,842		—		4,602

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 December 31, 2021 follows (in thousands):

Quantitative Information about Level 3 Non-recurring Fair Value Measurements
	Fair Value		Valuation Technique(s)	Significant Unobservable Input	Range (Weighted Average)
Nonaccruing loans	$	1,990	Discounted cash flows	Management knowledge of industry and non-real estate collateral including but not limited to recoverable oil & gas reserves, forward looking commodity prices, and estimated operating costs	16% - 97% (37%)1

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

A summary of quantitative information about Non-recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of December 31, 2020 follows (in thousands):

Quantitative Information about Level 3 Non-recurring Fair Value Measurements
	Fair Value		Valuation Technique(s)	Significant Unobservable Input	Range (Weighted Average)
Nonaccruing loans	$	20,423	Discounted cash flows	Management knowledge of industry and non-real estate collateral including but not limited to recoverable oil & gas reserves, forward looking commodity prices, and estimated operating costs	1% - 91% (23%)1
Real estate and other repossessed assets	2,842		Discounted cash flows	Management knowledge of industry and non-real estate collateral including but not limited to recoverable oil & gas reserves, forward looking commodity prices, and estimated operating costs	N/A

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

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, 2021
	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	$	712,067	$	712,067	$	712,067	$	—	$	—
Interest-bearing cash and cash equivalents	2,125,343		2,125,343		2,125,343		—		—
Trading securities:
U.S. government securities	23,610		23,610		4,999		18,611		—
Residential agency mortgage-backed securities	9,068,900		9,068,900		—		9,068,900		—
Municipal securities	25,783		25,783		—		25,783		—
Other trading securities	18,520		18,520		—		18,520		—
Total trading securities	9,136,813		9,136,813		4,999		9,131,814		—
Investment securities:
Municipal securities	203,772		223,609		—		57,698		165,911
Residential agency mortgage-backed securities	6,939		7,500		—		7,500		—
Other debt securities	288		286		—		286		—
Total investment securities	210,999		231,395		—		65,484		165,911
Allowance for credit losses	(555)		—		—		—		—
Investment securities, net of allowance	210,444		231,395		—		65,484		165,911
Available for sale securities:
U.S. Treasury	1,000		1,000		1,000		—		—
Municipal securities	508,365		508,365		—		508,365		—
Residential agency mortgage-backed securities	8,006,616		8,006,616		—		8,006,616		—
Residential non-agency mortgage-backed securities	24,339		24,339		—		24,339		—
Commercial agency mortgage-backed securities	4,617,025		4,617,025		—		4,617,025		—
Other debt securities	472		472		—		—		472
Total available for sale securities	13,157,817		13,157,817		1,000		13,156,345		472
Fair value option securities — Residential agency mortgage-backed securities	43,770		43,770		—		43,770		—
Residential mortgage loans held for sale	192,295		192,295		—		185,969		6,326
Loans:
Commercial	12,506,465		12,395,664		—		—		12,395,664
Commercial real estate	3,831,325		3,786,767		—		—		3,786,767
Paycheck protection program	276,341		269,912		—		—		269,912
Loans to individuals	3,591,549		3,586,878		—		—		3,586,878
Total loans	20,205,680		20,039,221		—		—		20,039,221
Allowance for loan losses	(256,421)		—		—		—		—
Loans, net of allowance	19,949,259		20,039,221		—		—		20,039,221
Mortgage servicing rights	163,198		163,198		—		—		163,198
Derivative instruments with positive fair value, net of cash margin	1,097,297		1,097,297		8,331		1,088,966		—
Deposits with no stated maturity	39,537,731		39,537,731		—		—		39,537,731
Time deposits	1,704,328		1,703,886		—		—		1,703,886
Other borrowed funds	2,363,202		2,360,746		—		—		2,360,746
Subordinated debentures	131,226		141,761		—		141,761		—
Derivative instruments with negative fair value, net of cash margin	275,625		275,625		—		275,625		—

	December 31, 2020
	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	$	798,757	$	798,757	$	798,757	$	—	$	—
Interest-bearing cash and cash equivalents	381,816		381,816		381,816		—		—
Trading securities:
U.S. government securities	9,183		9,183		4,999		4,184		—
Residential agency mortgage-backed securities	4,669,148		4,669,148		—		4,669,148		—
Municipal securities	19,172		19,172		—		19,172		—
Other trading securities	10,472		10,472		—		10,472		—
Total trading securities	4,707,975		4,707,975		4,999		4,702,976		—
Investment securities:
Municipal securities	229,245		255,270		—		69,404		185,866
Residential agency mortgage-backed securities	8,913		9,790		—		9,790		—
Other debt securities	7,373		7,371		—		7,371		—
Total investment securities	245,531		272,431		—		86,565		185,866
Allowance for credit losses	(688)		—		—		—		—
Investment securities, net of allowance	244,843		272,431		—		86,565		185,866
Available for sale securities:
U.S. Treasury securities	508		508		508		—		—
Municipal securities	167,979		167,979		—		167,979		—
Residential agency mortgage-backed securities	9,340,471		9,340,471		—		9,340,471		—
Residential non-agency mortgage-backed securities	32,770		32,770		—		32,770		—
Commercial agency mortgage-backed securities	3,508,465		3,508,465		—		3,508,465		—
Other debt securities	472		472		—		—		472
Total available for sale securities	13,050,665		13,050,665		508		13,049,685		472
Fair value option securities — Residential agency mortgage-backed securities	114,982		114,982		—		114,982		—
Residential mortgage loans held for sale	252,316		252,316		—		245,299		7,017
Loans:
Commercial	13,077,535		13,003,383		—		—		13,003,383
Commercial real estate	4,698,538		4,649,763		—		—		4,649,763
Paycheck protection program	1,682,310		1,669,461		—		—		1,669,461
Loans to individuals	3,549,137		3,563,199		—		—		3,563,199
Total loans	23,007,520		22,885,806		—		—		22,885,806
Allowance for loan losses	(388,640)		—		—		—		—
Loans, net of allowance	22,618,880		22,885,806		—		—		22,885,806
Mortgage servicing rights	101,172		101,172		—		—		101,172
Derivative instruments with positive fair value, net of cash margin	810,688		810,688		10,780		799,908		—
Deposits with no stated maturity	34,176,752		34,176,752		—		—		34,176,752
Time deposits	1,967,128		1,976,936		—		—		1,976,936
Other borrowed funds	3,545,356		3,542,489		—		—		3,542,489
Subordinated debentures	276,005		269,544		—		269,544		—
Derivative instruments with negative fair value, net of cash margin	405,779		405,779		—		405,779		—