Fair Value of Financial Instruments - Summary of Carrying Values and Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2025		Dec. 31, 2024
Financial assets
Investment securities	$ 61,529		$ 54,805
Loans held for sale, at lower of amortized cost or fair value	72,490		128,226
Equity securities, fair value	1,800		1,700
Level 1 [Member]
Financial assets
Cash, cash equivalents, and federal funds sold	750	[1]	168,322	[2]
Investment securities	61,529		0
Loans held for investment, net of allowance	0		0
Loans held for sale, at lower of amortized cost or fair value	0		0
Accrued interest receivable	0	[3]	15,314	[4]
Equity securities, fair value	0		1,732
Financial liabilities
Funds borrowed	2,318,531	[5]	0	[6]
Accrued interest payable	0		8,231
Level 2 [Member]
Financial assets
Cash, cash equivalents, and federal funds sold	0	[1]	1,250	[2]
Investment securities	0		54,805
Loans held for investment, net of allowance	2,255,160		0
Loans held for sale, at lower of amortized cost or fair value	75,573		0
Accrued interest receivable	0	[3]	0	[4]
Equity securities, fair value	0		0
Financial liabilities
Funds borrowed	0	[5]	2,371,434	[6]
Accrued interest payable	0		0
Level 3 [Member]
Financial assets
Cash, cash equivalents, and federal funds sold	151,244	[1]	0	[2]
Investment securities	0		0
Loans held for investment, net of allowance	0		2,238,645
Loans held for sale, at lower of amortized cost or fair value	0		133,244
Accrued interest receivable	15,294	[3]	0	[4]
Equity securities, fair value	1,763		0
Financial liabilities
Funds borrowed	0	[5]	0	[6]
Accrued interest payable	5,746		0
Carrying Amount [Member]
Financial assets
Cash, cash equivalents, and federal funds sold	151,994	[1]	169,572	[2]
Investment securities	61,529		54,805
Loans held for investment, net of allowance	2,305,665		2,265,428
Loans held for sale, at lower of amortized cost or fair value	72,490		128,226
Accrued interest receivable	15,294	[3]	15,314	[4]
Equity securities, fair value	1,763		1,732
Financial liabilities
Funds borrowed	2,304,317	[5]	2,379,413	[6]
Accrued interest payable	5,746		8,231
Fair Value Recurring [Member]
Financial assets
Cash, cash equivalents, and federal funds sold	151,994	[1]	169,572	[2]
Investment securities	61,529		54,805
Loans held for investment, net of allowance	2,255,160		2,238,645
Loans held for sale, at lower of amortized cost or fair value	75,573		133,244
Accrued interest receivable	15,294	[3]	15,314	[4]
Equity securities, fair value	1,763		1,732
Financial liabilities
Funds borrowed	2,318,531	[5]	2,371,434	[6]
Accrued interest payable	5,746		8,231
Fair Value Recurring [Member] | Level 1 [Member]
Financial assets
Equity securities, fair value	$ 1,763		$ 1,732

[1] Includes federal funds sold and interest bearing deposits in other banks.

[2] Includes federal funds sold and interest bearing deposits in other banks.

[3] Included within other assets on the balance sheet.

[4] Included within other assets on the balance sheet.

[5] Excludes deferred financing costs of $8.5 million.

[6] Excludes deferred financing costs of $8.2 million.