SHARE-BASED PAYMENT - Compensation Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Compensation costs
Share-based compensation	$ 24,075	$ 23,959	$ 21,134
Excess tax benefit recognized	4,632	6,848	9,545
Restricted shares
Compensation costs
Share-based compensation	17,818	14,741	12,336
Stock options
Compensation costs
Share-based compensation	625	1,124	1,570
PSP | RSUs
Compensation costs
Share-based compensation	$ 5,632	$ 8,094	$ 7,228