INCOME TAXES - Components of Income Tax - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating loss carryforwards
Effective tax rate (as a percent)			(2.80%)	46.60%
Net impact of the 2017 Tax Act			$ 10,600
U.S. federal statutory rate			35.00%
Benefit on the remeasurement of the deferred tax assets and liabilities			$ 18,000
Provision on the deemed repatriation of undistributed foreign earnings			7,400
Benefit for the net capital transactions			3,900
Benefit for an amended return refund claim			3,400
Increase (net) in unrecognized tax benefits related to current year and prior year positions			4,400
Provision (net) to record the change in valuation allowance			6,100
Provision related to certain transactional charges incurred in connection with our acquisitions				$ 3,100
Provision related to an impairment charge to write down the value of assets				2,622
Provision related to the write-off of an unrecoverable tax receivable				2,500
Operating loss carryforward that will expire			95,100
Operating loss carryforward with no expiration			3,700
Valuation allowance			35,829	42,462
Tax Credits			8,969
Net operating losses			26,685	29,571
Undistributed earnings of foreign subsidiaries			303,700
Undistributed earnings of foreign subsidiaries considered indefinitely reinvested			262,100
Guyana
Operating loss carryforwards
Cash distribution received from foreign subsidiaries with no impact of deferred tax liability	$ 41,600
Capital Loss Carryforward
Operating loss carryforwards
Tax Credits			8,200
Valuation allowance against capital loss			1,900
Federal
Operating loss carryforwards
Operating loss carryforwards			2,200
Capital loss carryforward that will expire			9,000
Valuation allowance			10,100
State
Operating loss carryforwards
NOL carryforward valuation allowance			0	500
Net operating losses			0
Foreign
Operating loss carryforwards
Operating loss carryforwards			96,600
Valuation allowance			25,700
NOL carryforward valuation allowance			24,300	27,800
Remaining valuation allowance applied to other foreign deferred taxes			$ 1,400	$ 14,100
Forecast
Operating loss carryforwards
U.S. federal statutory rate		21.00%