INCOME TAXES (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Effective income tax rate
Effective income tax rate (as a percent)	27.40%	31.80%	26.80%	31.40%
Excess discreate tax (benefit) provision on share-based payment awards (as a percent)	0.50%	1.50%	1.40%	1.90%
US federal corporate tax rate (as a percent)			21.00%		35.00%
Provisional amount related to the remeasurement of deferred tax balance					$ (7)
Transition tax liability for foreign subsidiaries, resulting in a transition tax liability					$ 3,140
Deferred Income Tax Benefit From Foreign Operating Losses And Tax Credit Carryforwards	$ 0		$ 0