SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS - Non-controlling Interest (Additional Information) (Details)	Jun. 30, 2026
X-Energy Reactor Company LLC
Summary Of Significant Accounting Policy [Line Items]
Non-controlling Interest	29.80%

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant