INVESTMENTS (Narrative) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Schedule of Investments [Line Items]
Trading securities	$ 4,335		$ 4,335		$ 4,161
Debt Securities, Available-for-sale, Allowance for Credit Loss	0		0		0
Net unrealized gain on available-for-sale debt securities, net of tax	8,958		8,958		29,310
Deferred tax assets, unrealized losses on available for sale securities	2,500		2,500		8,000
Debt Securities, Available-for-sale, Realized Gain (Loss)	0	$ 0	0	$ 0
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0		0		0
Debt Securities, Held-to-Maturity, Excluded Accrued Interest from Amortized Cost	8		8		10
Security pledged as collateral, amortized cost	720,400		720,400		485,000
Security pledged as collateral, fair value	728,900		728,900		507,100
Available-for-sale Securities
Schedule of Investments [Line Items]
Interest Receivable	$ 3,500		$ 3,500		$ 3,100