SHAREHOLDERS' EQUITY - Share repurchase activities (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 02, 2021
Treasury Shares [Line Items]
New share repurchase plan				$ 100,000
Common stocks
Treasury Shares [Line Items]
Total shares (in shares)	205	194	176
Total cost	$ 10,242	$ 10,382	$ 10,165
Average price per share (in usd per share)	$ 49.93	$ 53.43	$ 57.66
Common stocks | In the open market:
Treasury Shares [Line Items]
Total shares (in shares)	0	0	0
Total cost	$ 0	$ 0	$ 0
Average price per share (in usd per share)	$ 0	$ 0	$ 0
Common stocks | From employees:
Treasury Shares [Line Items]
Total shares (in shares)	205	194	176
Total cost	$ 10,242	$ 10,382	$ 10,165
Average price per share (in usd per share)	$ 49.93	$ 53.43	$ 57.66