Fair Value Measurements - Schedule of Investments in Debt Securities Held by Decommissioning Trust Fund (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Fair Value Measurements
Purchases	$ 209	$ 198	$ 12,051	$ 12,406
Net Proceeds	149	25	182	(579)
Unrealized Gain (Loss)	(18)	22	(106)	131
Debt securities held in decommissioning trust fund
Fair Value Measurements
Purchases	209	198	12,051	12,406
Net Proceeds	0	0	0	0
Unrealized Gain (Loss)	(18)	22	(106)	131
Cash and cash equivalents
Fair Value Measurements
Purchases	0	0	0	0
Net Proceeds	(7)	2	1	(745)
Unrealized Gain (Loss)	0	0	0	0
Other
Fair Value Measurements
Purchases	0	0	0	0
Net Proceeds	156	23	181	166
Unrealized Gain (Loss)	$ 0	$ 0	$ 0	$ 0

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/exampleRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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