v3.26.1
INVESTMENT SECURITIES - Summary of Amortized Cost and Approximate Fair Value of Investment Securities (Detail) - USD ($)
Mar. 31, 2026
Dec. 31, 2025
Schedule of Held-to-Maturity Securities [Line Items]    
Amortized Cost $ 663,545,000 $ 729,134,000
Allowance for Credit Losses 0 0
Net Carrying Value 663,545,000 729,134,000
Gross Unrealized Gains 140,000 678,000
Gross Unrealized Losses (55,223,000) (46,214,000)
Fair Value 608,462,000 683,598,000
Debt securities, held to maturity, accrued interest 1,300,000 1,500,000
Asset-backed securities    
Schedule of Held-to-Maturity Securities [Line Items]    
Amortized Cost 217,790,000 258,371,000
Allowance for Credit Losses 0 0
Net Carrying Value 217,790,000 258,371,000
Gross Unrealized Gains 140,000 678,000
Gross Unrealized Losses (2,426,000) (2,432,000)
Fair Value 215,504,000 256,617,000
Agency-guaranteed residential mortgage-backed securities    
Schedule of Held-to-Maturity Securities [Line Items]    
Amortized Cost 6,665,000 6,708,000
Allowance for Credit Losses 0 0
Net Carrying Value 6,665,000 6,708,000
Gross Unrealized Gains 0 0
Gross Unrealized Losses (754,000) (718,000)
Fair Value 5,911,000 5,990,000
Agency-guaranteed commercial mortgage-backed securities    
Schedule of Held-to-Maturity Securities [Line Items]    
Amortized Cost 1,666,000 1,687,000
Allowance for Credit Losses 0 0
Net Carrying Value 1,666,000 1,687,000
Gross Unrealized Gains 0 0
Gross Unrealized Losses (240,000) (238,000)
Fair Value 1,426,000 1,449,000
Agency-guaranteed residential collateralized mortgage obligations    
Schedule of Held-to-Maturity Securities [Line Items]    
Amortized Cost 150,633,000 153,662,000
Allowance for Credit Losses 0 0
Net Carrying Value 150,633,000 153,662,000
Gross Unrealized Gains 0 0
Gross Unrealized Losses (14,760,000) (10,629,000)
Fair Value 135,873,000 143,033,000
Agency-guaranteed commercial collateralized mortgage obligations    
Schedule of Held-to-Maturity Securities [Line Items]    
Amortized Cost 181,395,000 182,272,000
Allowance for Credit Losses 0 0
Net Carrying Value 181,395,000 182,272,000
Gross Unrealized Gains 0 0
Gross Unrealized Losses (26,123,000) (22,242,000)
Fair Value 155,272,000 160,030,000
Private label collateralized mortgage obligations    
Schedule of Held-to-Maturity Securities [Line Items]    
Amortized Cost 105,396,000 126,434,000
Allowance for Credit Losses 0 0
Net Carrying Value 105,396,000 126,434,000
Gross Unrealized Gains 0 0
Gross Unrealized Losses (10,920,000) (9,955,000)
Fair Value $ 94,476,000 $ 116,479,000