Loans Held for Investment and Allowance for Credit Losses on Loans (Tables)

12 Months Ended

Dec. 31, 2023

Receivables [Abstract]

Summary of Loans Held for Investment by Portfolio Segment

Loans held for investment are summarized by portfolio segment as follows:

	December 31,
	2023		2022
	(Dollars in thousands)
Real estate:
Commercial real estate owner occupied	$	960,944	$	908,494
Commercial real estate non-owner occupied		1,486,420		1,383,150
Construction and development < 60 months		642,643		475,236
Construction residential real estate < 60 months		283,486		303,305
Residential real estate first lien		1,258,744		1,117,899
Residential real estate all other		244,696		196,198
Agriculture		427,139		408,037
Commercial non-real estate		1,289,452		1,241,454
Consumer non-real estate		476,467		446,756
Oil and gas		586,654		463,034
Total (1)	$	7,656,645	$	6,943,563
(1) Excludes accrued interest receivable of $39.4 million at December 31, 2023 and $30.6 million at December 31, 2022, that is recorded in accrued interest
receivable and other assets.

Schedule of Portfolio Segments Weighted Average Life, and Measures the Allowance for Credit Losses

The Company has identified the following portfolio segments, which includes the applicable weighted average remaining life, and measures the allowance for credit losses using the vintage loss analysis adjusted for qualitative factors:

Portfolio Segments	Life (in years)
Real estate:
Commercial real estate owner occupied		9
Commercial real estate non-owner occupied		6
Construction and development < 60 months		3
Construction residential real estate < 60 months		2
Residential real estate first lien		15
Residential real estate all other		8
Agriculture		9
Commercial non-real estate		4
Consumer non-real estate		4
Oil and gas		2

Summary of Other Real Estate Owned and Repossessed Assets

The following is a summary of other real estate owned and repossessed assets:

	December 31,
	2023		2022
	(Dollars in thousands)
Other real estate owned and repossessed assets	$	34,200	$	36,936

Summary of Rental Income and Operating Expenses

This property had the following rental income and operating expenses for the periods presented.

	For the Twelve Months Ended December 31,
	2023		2022		2021
	(Dollars in thousands)
Rental income	$	11,224	$	10,340	$	9,975
Operating expense		10,868		9,863		8,727

Summary of Amounts Included in Nonaccrual Loans Segregated by Portfolio Segment

The following table is a summary of amounts included in nonaccrual loans, segregated by portfolio segment.

	December 31, 2023		December 31, 2022
	(Dollars in thousands)
Real estate:
Commercial real estate owner occupied	$	1,686	$	1,795
Commercial real estate non-owner occupied		874		667
Construction and development < 60 months		800		93
Construction residential real estate < 60 months		638		430
Residential real estate first lien		3,336		1,947
Residential real estate all other		899		55
Agriculture		3,662		2,734
Commercial non-real estate		10,101		7,066
Consumer non-real estate		449		192
Oil and gas		2,128		320
Total	$	24,573	$	15,299

Age Analysis of Loans Held for Investments

Loans are considered past due if the required principal and interest payments have not been received as of the date such payments were due. The following table presents an age analysis of the Company's loans held for investment:

	Age Analysis of Past Due Loans
	30-59 Days Past Due		60-89 Days Past Due		90 Days and Greater		Total Past Due Loans		Current Loans		Total Loans		Accruing Loans 90 Days or More Past Due
	(Dollars in thousands)
December 31, 2023
Real estate:
Commercial real estate owner    occupied	$	1,386	$	26	$	5,598	$	7,010	$	953,934	$	960,944	$	4,377
Commercial real estate non-owner    occupied		2,224		7,371		1,786		11,381		1,475,039		1,486,420		913
Construction and development <60    months		198		158		800		1,156		641,487		642,643		—
Construction residential real estate    < 60 months		1,542		206		405		2,153		281,333		283,486		332
Residential real estate first lien		3,879		1,204		1,849		6,932		1,251,812		1,258,744		731
Residential real estate all other		757		190		613		1,560		243,136		244,696		549
Agriculture		1,694		724		1,227		3,645		423,494		427,139		579
Commercial non-real estate		1,501		436		10,028		11,965		1,277,487		1,289,452		1,714
Consumer non-real estate		3,248		1,090		594		4,932		471,535		476,467		347
Oil and gas		—		—		92		92		586,562		586,654		—
Total	$	16,429	$	11,405	$	22,992	$	50,826	$	7,605,819	$	7,656,645	$	9,542
	30-59 Days Past Due		60-89 Days Past Due		90 Days and Greater		Total Past Due Loans		Current Loans		Total Loans		Accruing Loans 90 Days or More Past Due
	(Dollars in thousands)
December 31, 2022
Real estate:
Commercial real estate owner    occupied	$	1,314	$	1,524	$	4,580	$	7,418	$	901,076	$	908,494	$	4,580
Commercial real estate non-owner    occupied		6,237		—		42		6,279		1,376,871		1,383,150		43
Construction and development <60    months		535		40		114		689		474,547		475,236		81
Construction residential real estate    < 60 months		1,320		282		148		1,750		301,555		303,305		—
Residential real estate first lien		3,415		1,076		844		5,335		1,112,564		1,117,899		349
Residential real estate all other		265		37		185		487		195,711		196,198		166
Agriculture		2,357		34		2,265		4,656		403,381		408,037		1,054
Commercial non-real estate		2,490		2,142		2,772		7,404		1,234,050		1,241,454		345
Consumer non-real estate		2,591		648		585		3,824		442,932		446,756		467
Oil and gas		654		—		—		654		462,380		463,034		—
Total	$	21,178	$	5,783	$	11,535	$	38,496	$	6,905,067	$	6,943,563	$	7,085

Gross Loans Held for Investment by Year of Origination and Internally Assigned Credit Grades

The following tables summarizes the Company's gross loans held for investment by year of origination and internally assigned credit grades:

	Term Loans Amortized Cost Basis by Origination Year												Revolving Loans
	2023		2022		2021		2020		2019		Prior		Amortized Cost Basis		Total
	(Dollars in thousands)
December 31, 2023
Commercial real estate owner occupied
Grade 1	$	125,041	$	144,429	$	124,113	$	85,619	$	77,400	$	135,064	$	23,004	$	714,670
Grade 2		39,735		61,879		28,506		22,473		19,617		24,199		33,304		229,713
Grade 3		140		3,580		4,262		644		1,432		1,051		2,450		13,559
Grade 4		399		90		—		352		656		1,016		150		2,663
Grade 5		—		—		—		—		339		—		—		339
Total commercial real estate owner occupied		165,315		209,978		156,881		109,088		99,444		161,330		58,908		960,944
Commercial real estate non-owner occupied
Grade 1		221,014		271,637		172,291		113,676		56,831		68,576		44,878		948,903
Grade 2		82,206		139,982		79,204		53,154		63,331		72,075		28,844		518,796
Grade 3		2,135		6,666		1,715		—		6,207		251		—		16,974
Grade 4		200		632		349		—		—		566		—		1,747
Total commercial real estate non-owner occupied		305,555		418,917		253,559		166,830		126,369		141,468		73,722		1,486,420
Construction and development < 60 months
Grade 1		124,218		133,254		65,472		5,828		3,392		5,019		76,831		414,014
Grade 2		95,138		43,884		28,772		6,625		13,406		2,146		34,559		224,530
Grade 3		2,051		893		101		235		—		19		—		3,299
Grade 4		—		800		—		—		—		—		—		800
Total construction and development < 60 months		221,407		178,831		94,345		12,688		16,798		7,184		111,390		642,643
Construction residential real estate < 60 months
Grade 1		158,161		7,551		1,421		100		105		467		49,284		217,089
Grade 2		57,172		2,365		27		12		—		—		98		59,674
Grade 3		5,457		387		—		—		—		—		—		5,844
Grade 4		673		206		—		—		—		—		—		879
Total construction residential real estate <60 months		221,463		10,509		1,448		112		105		467		49,382		283,486
Residential real estate first lien
Grade 1		294,363		226,557		174,325		115,055		71,941		149,836		6,047		1,038,124
Grade 2		51,619		39,146		35,226		24,738		12,591		39,264		—		202,584
Grade 3		2,175		2,187		2,630		773		1,140		4,009		—		12,914
Grade 4		759		122		1,144		651		355		2,091		—		5,122
Total residential real estate first lien		348,916		268,012		213,325		141,217		86,027		195,200		6,047		1,258,744
Residential real estate all other
Grade 1		44,475		24,861		8,381		8,122		3,753		12,827		46,479		148,898
Grade 2		4,244		5,819		1,415		1,652		1,308		2,527		74,388		91,353
Grade 3		355		262		198		40		23		391		1,942		3,211
Grade 4		119		24		—		—		55		89		947		1,234
Total residential real estate all other		49,193		30,966		9,994		9,814		5,139		15,834		123,756		244,696
Agriculture
Grade 1		52,934		51,099		34,840		26,603		17,863		33,052		46,981		263,372
Grade 2		28,829		20,931		18,245		9,826		8,207		15,833		41,018		142,889
Grade 3		9,516		1,185		789		2,570		296		2,372		2,454		19,182
Grade 4		265		633		55		131		370		241		1		1,696
Total agriculture		91,544		73,848		53,929		39,130		26,736		51,498		90,454		427,139
Commercial non-real estate
Grade 1		252,112		176,013		159,470		39,097		36,907		33,824		277,740		975,163
Grade 2		95,590		35,955		19,519		6,591		6,456		8,071		127,800		299,982
Grade 3		2,206		2,598		1,011		109		121		164		1,779		7,988
Grade 4		1,181		1,691		400		686		309		154		1,425		5,846
Grade 5		—		—		—		—		473		—		—		473
Total commercial non-real estate		351,089		216,257		180,400		46,483		44,266		42,213		408,744		1,289,452
Consumer non-real estate
Grade 1		211,028		105,365		55,079		18,529		8,939		3,301		22,184		424,425
Grade 2		19,085		14,919		6,764		2,062		702		910		2,085		46,527
Grade 3		941		1,424		932		326		299		156		11		4,089
Grade 4		361		452		409		117		72		10		5		1,426
Total consumer non-real estate		231,415		122,160		63,184		21,034		10,012		4,377		24,285		476,467
Oil and gas
Grade 1		147,902		29,658		72,127		13,898		1,553		15,015		180,321		460,474
Grade 2		66,080		4,851		1,019		402		279		177		50,201		123,009
Grade 3		1,758		132		225		—		—		—		323		2,438
Grade 4		313		83		166		—		10		161		—		733
Total oil and gas		216,053		34,724		73,537		14,300		1,842		15,353		230,845		586,654
Total loans held for investment	$	2,201,950	$	1,564,202	$	1,100,602	$	560,696	$	416,738	$	634,924	$	1,177,533	$	7,656,645

	Term Loans Amortized Cost Basis by Origination Year												Revolving Loans
	2022		2021		2020		2019		2018		Prior		Amortized Cost Basis		Total
	(Dollars in thousands)
December 31, 2022
Commercial real estate owner occupied
Grade 1	$	173,596	$	145,425	$	106,285	$	91,892	$	44,086	$	119,755	$	53,026	$	734,065
Grade 2		34,774		34,283		27,153		17,999		8,528		29,638		14,737		167,112
Grade 3		235		1,718		387		1,334		332		1,161		62		5,229
Grade 4		40		269		—		1,110		180		489		—		2,088
Total commercial real estate owner occupied		208,645		181,695		133,825		112,335		53,126		151,043		67,825		908,494
Commercial real estate non-owner occupied
Grade 1		349,333		239,369		170,186		107,983		24,075		66,546		45,372		1,002,864
Grade 2		115,372		50,573		29,031		46,870		24,877		69,601		31,928		368,252
Grade 3		7,677		—		153		2,733		64		1,318		—		11,945
Grade 4		—		—		—		—		42		47		—		89
Total commercial real estate non-owner occupied		472,382		289,942		199,370		157,586		49,058		137,512		77,300		1,383,150
Construction and development < 60 months
Grade 1		164,865		92,595		39,819		5,558		3,146		4,993		40,474		351,450
Grade 2		36,090		20,273		1,413		14,248		1,648		774		47,973		122,419
Grade 3		967		—		141		—		—		8		158		1,274
Grade 4		—		—		33		47		—		13		—		93
Total construction and development < 60 months		201,922		112,868		41,406		19,853		4,794		5,788		88,605		475,236
Construction residential real estate < 60 months
Grade 1		209,699		12,612		259		18		—		42		36,114		258,744
Grade 2		39,174		1,152		102		—		—		400		2,091		42,919
Grade 3		1,212		—		—		—		—		—		—		1,212
Grade 4		420		10		—		—		—		—		—		430
Total construction residential real estate < 60 months		250,505		13,774		361		18		—		442		38,205		303,305
Residential real estate first lien
Grade 1		303,369		205,377		141,752		85,850		55,631		136,776		4,242		932,997
Grade 2		46,751		36,453		25,623		13,414		11,687		37,167		—		171,095
Grade 3		1,940		1,903		1,065		1,689		497		3,826		—		10,920
Grade 4		55		311		175		386		144		1,816		—		2,887
Total residential real estate first lien		352,115		244,044		168,615		101,339		67,959		179,585		4,242		1,117,899
Residential real estate all other
Grade 1		31,741		11,012		10,696		5,458		3,607		11,198		41,653		115,365
Grade 2		5,683		1,887		1,744		1,589		1,237		2,574		62,395		77,109
Grade 3		381		186		71		50		201		786		1,828		3,503
Grade 4		—		18		28		32		39		53		51		221
Total residential real estate all other		37,805		13,103		12,539		7,129		5,084		14,611		105,927		196,198
Agriculture
Grade 1		73,722		44,037		35,684		22,094		12,064		31,517		42,542		261,660
Grade 2		28,351		22,773		9,638		10,548		6,025		15,233		33,844		126,412
Grade 3		6,435		476		3,427		140		320		2,703		4,452		17,953
Grade 4		660		221		498		80		144		393		16		2,012
Total agriculture		109,168		67,507		49,247		32,862		18,553		49,846		80,854		408,037
Commercial non-real estate
Grade 1		282,252		205,516		67,229		50,725		13,780		40,989		280,774		941,265
Grade 2		88,017		46,604		17,420		11,447		15,628		3,582		105,783		288,481
Grade 3		2,093		461		346		738		1,566		180		2,544		7,928
Grade 4		240		415		656		745		348		929		183		3,516
Grade 5		—		—		—		264		—		—		—		264
Total commercial non-real estate		372,602		252,996		85,651		63,919		31,322		45,680		389,284		1,241,454
Consumer non-real estate
Grade 1		203,238		104,380		39,779		21,035		6,589		2,187		26,263		403,471
Grade 2		21,011		10,538		3,978		1,541		822		1,340		825		40,055
Grade 3		827		671		405		282		134		63		4		2,386
Grade 4		229		351		54		141		56		13		—		844
Total consumer non-real estate		225,305		115,940		44,216		22,999		7,601		3,603		27,092		446,756
Oil and gas
Grade 1		24,303		125,209		16,482		682		1,678		880		199,995		369,229
Grade 2		7,610		10,668		766		23,040		3,167		327		45,240		90,818
Grade 3		2,117		47		5		—		—		—		498		2,667
Grade 4		—		320		—		—		—		—		—		320
Total oil and gas		34,030		136,244		17,253		23,722		4,845		1,207		245,733		463,034
Total loans held for investment	$	2,264,479	$	1,428,113	$	752,483	$	541,762	$	242,342	$	589,317	$	1,125,067	$	6,943,563

Gross Charge-offs by Year of Origination

The following tables summarize the Company’s gross charge-offs by year of origination for the periods indicated:

	Term Loans Amortized Cost Basis by Origination Year												Revolving Loans
	2023		2022		2021		2020		2019		Prior		Amortized Cost Basis		Total
	(Dollars in thousands)
Year ended December 31, 2023
Commercial real estate owner occupied
Current-period gross charge-offs	$	174	$	196	$	26	$	203	$	165	$	158	$	—	$	922
Commercial real estate non-owner occupied
Current-period gross charge-offs		—		—		—		—		—		3		—		3
Construction and development < 60 months
Current-period gross charge-offs		—		3		—		2		—		1		—		6
Construction residential real estate < 60 months
Current-period gross charge-offs		—		94		—		—		—		—		—		94
Residential real estate first lien
Current-period gross charge-offs		—		—		91		44		5		25		—		165
Residential real estate all other
Current-period gross charge-offs		—		4		19		—		1		36		—		60
Agriculture
Current-period gross charge-offs		—		154		9		317		14		2		—		496
Commercial non-real estate
Current-period gross charge-offs		390		351		111		22		51		160		—		1,085
Consumer non-real estate
Current-period gross charge-offs		312		632		261		45		41		40		19		1,350
Oil and gas
Current-period gross charge-offs		57		2		—		—		—		—		—		59
Total current-period gross charge-offs	$	933	$	1,436	$	517	$	633	$	277	$	425	$	19	$	4,240

Activity in Allowance for Credit Losses on Loans

The following table details activity in the allowance for credit losses on loans for the period presented. Allocation of a portion of the allowance to one category of loans does not preclude its availability to absorb losses in other categories.

	Allowance for Credit Losses
	Balance at beginning of period		Charge- offs			Recoveries		Net charge-offs			Provision for/(benefit from) credit losses on loans			Balance at end of period
	(Dollars in thousands)
Year ended December 31, 2023
Real estate:
Commercial real estate owner occupied	$	6,416	$	(922	)	$	68	$	(854	)	$	1,921		$	7,483
Commercial real estate non-owner occupied		30,190		(3	)		—		(3	)		2,893			33,080
Construction and development < 60 months		3,778		(6	)		11		5			167			3,950
Construction residential real estate < 60 months		3,275		(94	)		—		(94	)		233			3,414
Residential real estate first lien		4,092		(165	)		15		(150	)		972			4,914
Residential real estate all other		1,418		(60	)		5		(55	)		283			1,646
Agriculture		6,217		(496	)		127		(369	)		289			6,137
Commercial non-real estate		25,106		(1,085	)		446		(639	)		(1,722	)		22,745
Consumer non-real estate		4,132		(1,350	)		182		(1,168	)		1,437			4,401
Oil and gas		8,104		(59	)		—		(59	)		985			9,030
Total	$	92,728	$	(4,240	)	$	854	$	(3,386	)	$	7,458		$	96,800

	Allowance for Credit Losses
	Balance at beginning of period		Initial allowance on loans purchased with credit deterioration		Charge- offs			Recoveries		Net charge-offs			Provision for/(benefit from) credit losses on loans			Balance at end of period
	(Dollars in thousands)
Year ended December 31, 2022
Real estate:
Commercial real estate owner occupied	$	7,550	$	—	$	(20	)	$	507	$	487		$	(1,621	)	$	6,416
Commercial real estate non-owner occupied		16,807		—		—			—		—			13,383			30,190
Construction and development < 60 months		3,454		—		(93	)		12		(81	)		405			3,778
Construction residential real estate    < 60 months		1,051		—		—			—		—			2,224			3,275
Residential real estate first lien		3,048		2		(106	)		87		(19	)		1,061			4,092
Residential real estate all other		1,567		—		(38	)		405		367			(516	)		1,418
Agriculture		8,392		—		(205	)		13		(192	)		(1,983	)		6,217
Commercial non-real estate		25,565		44		(1,551	)		209		(1,342	)		839			25,106
Consumer non-real estate		3,694		25		(768	)		193		(575	)		988			4,132
Oil and gas		12,808		—		—			—		—			(4,704	)		8,104
Total	$	83,936	$	71	$	(2,781	)	$	1,426	$	(1,355	)	$	10,076		$	92,728

Purchased Credit Deteriorated Loans

The Company has purchased loans, for which there was, at acquisition, evidence of more than insignificant deterioration of credit quality since origination. The Company did not purchase credit-deteriorated loans during the year ended December 31, 2023. The credit-deteriorated loans purchased during the year ended December 31, 2022 were as follows:

	Loans acquired with deteriorated credit quality
	(Dollars in thousands)
For the year ended December 31, 2022
Purchase price of loans at acquisition	$	668
Allowance for credit losses at acquisition		71
Par value of acquired loans at acquisition	$	739

Collateral-Dependent Gross Loans Held for Investment by Collateral Type and Related Specific Allocation

The following table summarizes collateral-dependent gross loans held for investment by collateral type and the related specific allocation as follows:

	Collateral Type
	Real Estate		Business Assets		Energy Reserves		Other Assets		Total		Specific Allocation
As of December 31, 2023	(Dollars in thousands)
Real estate:
Commercial real estate owner occupied	$	—	$	—	$	—	$	—	$	—	$	—
Commercial real estate non-owner occupied		632		—		—		—		632		250
Construction and development < 60 months		800		—		—		—		800		225
Construction residential real estate < 60 months		638		—		—		—		638		134
Residential real estate first lien		189		—		—		—		189		62
Residential real estate all other		140		—		—		—		140		140
Agriculture		1,841		593		—		15		2,449		1,386
Commercial non-real estate		—		6,090		—		241		6,331		1,867
Consumer non-real estate		—		—		—		147		147		88
Oil and gas		—		—		—		—		—		—
Total collateral-dependent loans held for investment	$	4,240	$	6,683	$	—	$	403	$	11,326	$	4,152
	Collateral Type
	Real Estate		Business Assets		Energy Reserves		Other Assets		Total		Specific Allocation
As of December 31, 2022	(Dollars in thousands)
Real estate:
Commercial real estate owner occupied	$	2,213	$	—	$	—	$	—	$	2,213	$	870
Commercial real estate non-owner occupied		1,263		—		—		—		1,263		333
Construction and development < 60 months		—		—		—		—		—		—
Construction residential real estate < 60 months		420		—		—		—		420		45
Residential real estate first lien		481		—		—		—		481		207
Residential real estate all other		9		—		—		—		9		9
Agriculture		3,447		701		—		3,592		7,740		3,114
Commercial non-real estate		—		5,924		—		4		5,928		1,938
Consumer non-real estate		—		—		—		117		117		81
Oil and gas		—		—		—		—		—		—
Total collateral-dependent loans held for investment	$	7,833	$	6,625	$	—	$	3,713	$	18,171	$	6,597

Transfers from Loans and Premises and Equipment to Other Real Estate Owned, Repossessed Assets and Other Assets

Transfers from loans and premises and equipment to other real estate owned, repossessed assets, and other assets during the periods presented are summarized as follows:

	Year ended December 31,
	2023		2022		2021
	(Dollars in thousands)
Other real estate owned	$	3,459	$	2,563	$	12,651
Repossessed assets		2,019		1,040		844
Other assets		—		1,943		—
Total	$	5,478	$	5,546	$	13,495

Related Party Loans

A summary of these loans is as follows:

Year Ended December 31,	Balance Beginning of the Period		Additions		Collections/ Terminations			Balance End of the Period
	(Dollars in thousands)
2023	$	23,167	$	106,819	$	(45,722	)	$	84,264
2022		28,292		46,124		(51,249	)		23,167
2021		22,057		31,574		(25,339	)		28,292