Preferred Shares - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		9 Months Ended
	Apr. 11, 2018	Sep. 30, 2022	Dec. 31, 2021
Class of Stock [Line Items]
Fair value of preferred stock consideration	$ 132,750
Preferred stock redemption value		$ 73,594	$ 90,741
Preferred Stock [Member]
Class of Stock [Line Items]
Other redemption rights unrelated to stockholder approval		Temporary equity classification is required for redeemable instruments for which redemption triggers are outside of the issuer’s control. ETFS Capital has the right to redeem all the Preferred Shares specified to be converted during the period of time specified in the Certificate of Designations in the event that: (a) the number of shares of the Company’s common stock authorized by its certificate of incorporation is insufficient to permit the Company to convert all of the Preferred Shares requested by ETFS Capital to be converted; or (b) ETFS Capital does not, upon completion of a change of control of the Company, receive the same amount per Preferred Share as it would have received had each outstanding Preferred Share been converted into common stock immediately prior to the change of control. However, the Company will not be obligated to make any such redemption payments to the extent such payments would be a breach of any covenant or obligation the Company owes to any of its secured creditors or is otherwise prohibited by applicable law.
Acquisition of ETFS Business [Member] | Preferred Stock [Member]
Class of Stock [Line Items]
Shares issued in business acquisition	14,750
Acquisition of ETFS Business [Member] | Common Stock [Member]
Class of Stock [Line Items]
Common stock equivalents	14,750,000
Series of Individually Immaterial Business Acquisitions [Member]
Class of Stock [Line Items]
Acquisition price per share	$ 9