Commitments and Contingencies - Schedule of SRC Arrangements (Details) $ in Thousands	Jun. 30, 2026 USD ($)
Other Commitments [Line Items]
Advances paid	$ 13,583
Total Commitments	71,326
Remaining Commitments	57,743
Pilot HREE Metallization
Other Commitments [Line Items]
Advances paid	1,315
Total Commitments	10,492
Remaining Commitments	9,177
Commercial HREE Metallization
Other Commitments [Line Items]
Advances paid	8,370
Total Commitments	40,219
Remaining Commitments	31,849
SRC REPF Upgrade
Other Commitments [Line Items]
Advances paid	3,898
Total Commitments	20,615
Remaining Commitments	$ 16,717

Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 235
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477314/942-235-S99-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-4

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-3

Name:	us-gaap_OtherCommitment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant