Fair Value Measurements - Recurring and Nonrecurring Fair Value Measurements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Fair Value Measurements
Other than temporary impairment related to Vast	$ 7,500	$ 15,400
Common share warrants
Fair Value Measurements
Warrants, at fair value	700	9,000
Level 1
Fair Value Measurements
Restricted cash held in trust, fair value	0	331,800
Level 2
Fair Value Measurements
Short-term investments, fair value	31	7,600
Level 3
Fair Value Measurements
Assets, fair Value	$ 0	$ 0