Basis of Presentation - Additional Information (Detail) - USD ($)		3 Months Ended		6 Months Ended
	May 28, 2019	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Significant Accounting Policies [Line Items]
Preferred stock, share outstanding		0		0		0
Deferred tax assets, valuation allowance		$ 80,311,000		$ 80,311,000
Restricted cash		10,053,000		10,053,000		$ 10,565,000
Lower of cost or market inventory adjustment				0
Production cost		5,861,000	$ 6,834,000	14,345,000	$ 16,557,000
Pic Onyx Inc
Significant Accounting Policies [Line Items]
Minority interest		4,300,000		4,300,000
Gain (loss) recorded at inception	$ 0
Exchange for convertible promissory note	$ 500,000
Convertible promissory note interest	7.50%
Convertible promissory maturing date	Aug. 01, 2021
Preferred stock voting percentage	22.00%
Non-cash change in property, plant and equipment and Intangible and other assets, net		3,500,000		3,500,000
Non-cash change in accounts payable and intangible and other assets, net		$ 400,000		$ 400,000
Pic Onyx Inc | Convertible Preferred Stock
Significant Accounting Policies [Line Items]
Preferred stock, share outstanding	9,700,000
Eufaula and Alabama
Significant Accounting Policies [Line Items]
Percentage of value of assets of project on construction in progress				82.00%
Projects completed percentage				75.00%