Capitalized Interest - Summary of Interest Costs Incurred, Capitalized, Expensed and Charged to Cost of Sales (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Capitalized Interest Costs Including Allowance for Funds Used During Construction RollForward
Interest capitalized, beginning of year	$ 3,499	$ 4,154	$ 5,583
Interest incurred	41,327	26,463	26,277
Interest expense	(40,872)	(25,380)	(25,081)
Interest charged to cost of sales	(2,929)	(1,738)	(2,625)
Interest capitalized, end of year	$ 1,025	$ 3,499	$ 4,154