FAIR VALUE MEASUREMENTS (Reported Amounts and Estimated Fair Values of the Financial Assets and Liabilities for Which Disclosure of Fair Value is Required) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Financial Liabilities:
Short-term debt	$ 16,018	$ 0
Nonrecurring | Balance
Financial Assets:
Cash equivalents:	78,302	153,783
Restricted cash	2,722	1,390
Employee loans	818	794
Financial Liabilities:
Short-term debt	16,018
Other long term debt	5,234
Nonrecurring | Balance | Money market funds
Financial Assets:
Cash equivalents:	78,302	153,783
Nonrecurring | Balance | Time Deposits
Financial Assets:
Time deposits included in Short-term investments		60,007
Nonrecurring | Balance | Revolving credit facility | 2021 Credit Facility
Financial Liabilities:
Borrowings	25,000
Nonrecurring | Balance | Revolving credit facility | 2017 Credit Facility
Financial Liabilities:
Borrowings		25,007
Nonrecurring | Estimated Fair Value
Financial Assets:
Cash equivalents:	78,302	153,783
Restricted cash	2,722	1,390
Employee loans	818	794
Financial Liabilities:
Short-term debt	16,018
Other long term debt	5,234
Nonrecurring | Estimated Fair Value | Money market funds
Financial Assets:
Cash equivalents:	78,302	153,783
Nonrecurring | Estimated Fair Value | Time Deposits
Financial Assets:
Time deposits included in Short-term investments		60,007
Nonrecurring | Estimated Fair Value | Revolving credit facility | 2021 Credit Facility
Financial Liabilities:
Borrowings	25,000
Nonrecurring | Estimated Fair Value | Revolving credit facility | 2017 Credit Facility
Financial Liabilities:
Borrowings		25,007
Nonrecurring | Estimated Fair Value | Level 1
Financial Assets:
Cash equivalents:	78,302	153,783
Restricted cash	2,722	1,390
Employee loans	0	0
Financial Liabilities:
Short-term debt	0
Other long term debt	0
Nonrecurring | Estimated Fair Value | Level 1 | Money market funds
Financial Assets:
Cash equivalents:	78,302	153,783
Nonrecurring | Estimated Fair Value | Level 1 | Time Deposits
Financial Assets:
Time deposits included in Short-term investments		0
Nonrecurring | Estimated Fair Value | Level 1 | Revolving credit facility | 2021 Credit Facility
Financial Liabilities:
Borrowings	0
Nonrecurring | Estimated Fair Value | Level 1 | Revolving credit facility | 2017 Credit Facility
Financial Liabilities:
Borrowings		0
Nonrecurring | Estimated Fair Value | Level 2
Financial Assets:
Cash equivalents:	0	0
Restricted cash	0	0
Employee loans	0	0
Financial Liabilities:
Short-term debt	16,018
Other long term debt	5,234
Nonrecurring | Estimated Fair Value | Level 2 | Money market funds
Financial Assets:
Cash equivalents:	0	0
Nonrecurring | Estimated Fair Value | Level 2 | Time Deposits
Financial Assets:
Time deposits included in Short-term investments		60,007
Nonrecurring | Estimated Fair Value | Level 2 | Revolving credit facility | 2021 Credit Facility
Financial Liabilities:
Borrowings	25,000
Nonrecurring | Estimated Fair Value | Level 2 | Revolving credit facility | 2017 Credit Facility
Financial Liabilities:
Borrowings		25,007
Nonrecurring | Estimated Fair Value | Level 3
Financial Assets:
Cash equivalents:	0	0
Restricted cash	0	0
Employee loans	818	794
Financial Liabilities:
Short-term debt	0
Other long term debt	0
Nonrecurring | Estimated Fair Value | Level 3 | Money market funds
Financial Assets:
Cash equivalents:	0	0
Nonrecurring | Estimated Fair Value | Level 3 | Time Deposits
Financial Assets:
Time deposits included in Short-term investments		0
Nonrecurring | Estimated Fair Value | Level 3 | Revolving credit facility | 2021 Credit Facility
Financial Liabilities:
Borrowings	$ 0
Nonrecurring | Estimated Fair Value | Level 3 | Revolving credit facility | 2017 Credit Facility
Financial Liabilities:
Borrowings		$ 0