MONEY MARKET INVESTMENTS (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash and Cash Equivalents [Line Items]
Time deposits with other financial institutions	$ 300	$ 300
Other short-term investments	60,272	97,408
Money Market Funds At Carrying Value	$ 60,572	$ 97,708	$ 7,590
Weighted average interest rate, time deposits with other financial institutions	0.45%	1.00%
Other short-term investments [Member]
Cash and Cash Equivalents [Line Items]
Other short-term investments	$ 1,181	$ 1,180
Weighted average rate, other short-term investments	0.11%	0.11%
Overnight deposits with other financial institutions [Member]
Cash and Cash Equivalents [Line Items]
Other short-term investments	$ 59,091	$ 96,228
Weighted average rate, other short-term investments	0.15%	1.63%