Plant, Equipment and Timberlands - Summary of Interest Expense Capitalized (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest Expense [Abstract]
Interest cost incurred	$ 10,408	$ 16,005	$ 15,066
Interest capitalized		396	1,749
Interest expense	$ 10,408	$ 15,609	$ 13,317