Tembec Acquisition - Pro Forma (Details) - Tembec Inc. $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) $ / shares
Business Acquisition [Line Items]
Unaudited pro forma net revenue (includes the results of the Matane mill) | $	$ 2,122,000
Unaudited pro forma net income attributable to the Company | $	$ 111,000
Unaudited pro forma basic net income per share (in USD per share) | $ / shares	$ 1.92
Unaudited pro forma diluted net income per share (in USD per share) | $ / shares	$ 1.76