Amount of expense related to royalty payments under a contractual arrangement such as payment for mineral and drilling rights and use of technology or intellectual property.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.3)
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

Name:	us-gaap_RoyaltyExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Jan. 22, 2013	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Commitments and Contingencies
Common stock issued for services (in shares)		4,263		8,791
License agreement with ANR
Commitments and Contingencies
Percentage of royalty on net revenue	4.00%
Royalty expense		$ 5	$ 3	$ 12	$ 6