FAIR VALUE MEASUREMENTS (Estimated Fair Values of the Financial Assets and Liabilities not Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Financial Liabilities:
Short term debt	$ 9,900	$ 16,018
Recurring | Balance
Financial Assets:
Cash equivalents:	63,817	78,302
Restricted cash	31,464	2,722
Employee loans	922	818
Financial Liabilities:
Short term debt	9,900	16,018
Other long term debt	5,550	5,234
Recurring | Balance | Money market funds
Financial Assets:
Cash equivalents:	63,817	78,302
Recurring | Balance | Revolving credit facility | Credit Facility 2021
Financial Liabilities:
Borrowings under the 2021 Credit Agreement	25,000	25,000
Recurring | Estimated Fair Value
Financial Assets:
Cash equivalents:	63,817	78,302
Restricted cash	31,464	2,722
Employee loans	922	818
Financial Liabilities:
Short term debt	9,900	16,018
Other long term debt	5,550	5,234
Recurring | Estimated Fair Value | Money market funds
Financial Assets:
Cash equivalents:	63,817	78,302
Recurring | Estimated Fair Value | Revolving credit facility | Credit Facility 2021
Financial Liabilities:
Borrowings under the 2021 Credit Agreement	25,000	25,000
Recurring | Estimated Fair Value | Level 1
Financial Assets:
Cash equivalents:	63,817	78,302
Restricted cash	31,464	2,722
Employee loans	0	0
Financial Liabilities:
Short term debt	0	0
Other long term debt	0	0
Recurring | Estimated Fair Value | Level 1 | Money market funds
Financial Assets:
Cash equivalents:	63,817	78,302
Recurring | Estimated Fair Value | Level 1 | Revolving credit facility | Credit Facility 2021
Financial Liabilities:
Borrowings under the 2021 Credit Agreement	0	0
Recurring | Estimated Fair Value | Level 2
Financial Assets:
Cash equivalents:	0	0
Restricted cash	0	0
Employee loans	0	0
Financial Liabilities:
Short term debt	9,900	16,018
Other long term debt	5,550	5,234
Recurring | Estimated Fair Value | Level 2 | Money market funds
Financial Assets:
Cash equivalents:	0	0
Recurring | Estimated Fair Value | Level 2 | Revolving credit facility | Credit Facility 2021
Financial Liabilities:
Borrowings under the 2021 Credit Agreement	25,000	25,000
Recurring | Estimated Fair Value | Level 3
Financial Assets:
Cash equivalents:	0	0
Restricted cash	0	0
Employee loans	922	818
Financial Liabilities:
Short term debt	0	0
Other long term debt	0	0
Recurring | Estimated Fair Value | Level 3 | Money market funds
Financial Assets:
Cash equivalents:	0	0
Recurring | Estimated Fair Value | Level 3 | Revolving credit facility | Credit Facility 2021
Financial Liabilities:
Borrowings under the 2021 Credit Agreement	$ 0	$ 0