INCOME TAXES - Schedule of Capital Losses and Net Operating Losses (Details) $ in Thousands	Dec. 31, 2016 USD ($)
Operating Loss Carryforwards [Line Items]
Net operating losses expected to expire	$ 75,000
Capital losses | United States
Operating Loss Carryforwards [Line Items]
Amount	54,399
Net operating losses | United States
Operating Loss Carryforwards [Line Items]
Amount	224,923
CANADA | Non-capital losses | Canada
Operating Loss Carryforwards [Line Items]
Amount	25,699
CANADA | Capital losses | Canada
Operating Loss Carryforwards [Line Items]
Amount	3,221
CANADA | Investment Tax Credits | Canada
Operating Loss Carryforwards [Line Items]
Amount	$ 1,187