Fair Value Measurements - Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Assets:
Available-for-sale securities	$ 149,325	$ 139,569
Short-term investments	149,325	139,569
U.S. government securities
Assets:
Available-for-sale securities	148,795	64,880
Zero coupon bonds
Assets:
Available-for-sale securities		74,159
Certificates of deposit
Assets:
Available-for-sale securities	530	530
Fair value measured on recurring basis | U.S. government securities
Assets:
Available-for-sale securities	148,795	64,880
Fair value measured on recurring basis | Zero coupon bonds
Assets:
Available-for-sale securities		74,159
Fair value measured on recurring basis | Convertible promissory note
Assets:
Available-for-sale securities		1,880
Short-term investments	3,528
Fair value measured on recurring basis | Certificates of deposit
Assets:
Short-term investments		530
Derivative assets	530
Fair value measured on recurring basis | Embedded derivatives
Assets:
Derivative assets	6,329	6,755
Fair value measured on recurring basis | Commodity swap contracts
Liabilities:
Derivative liabilities	3,723	3,845
Fair value measured on recurring basis | Level 1 | U.S. government securities
Assets:
Available-for-sale securities	148,795	64,880
Fair value measured on recurring basis | Level 1 | Zero coupon bonds
Assets:
Available-for-sale securities		0
Fair value measured on recurring basis | Level 1 | Convertible promissory note
Assets:
Available-for-sale securities		0
Short-term investments	0
Fair value measured on recurring basis | Level 1 | Certificates of deposit
Assets:
Short-term investments		0
Derivative assets	0
Fair value measured on recurring basis | Level 1 | Embedded derivatives
Assets:
Derivative assets		0
Fair value measured on recurring basis | Level 1 | Commodity swap contracts
Liabilities:
Derivative liabilities	0	0
Fair value measured on recurring basis | Level 2 | U.S. government securities
Assets:
Available-for-sale securities	0	0
Fair value measured on recurring basis | Level 2 | Zero coupon bonds
Assets:
Available-for-sale securities		74,159
Fair value measured on recurring basis | Level 2 | Convertible promissory note
Assets:
Available-for-sale securities		0
Short-term investments	0
Fair value measured on recurring basis | Level 2 | Certificates of deposit
Assets:
Short-term investments		530
Derivative assets	530
Fair value measured on recurring basis | Level 2 | Embedded derivatives
Assets:
Derivative assets		0
Fair value measured on recurring basis | Level 2 | Commodity swap contracts
Liabilities:
Derivative liabilities	0	0
Fair value measured on recurring basis | Level 3 | U.S. government securities
Assets:
Available-for-sale securities	0	0
Fair value measured on recurring basis | Level 3 | Zero coupon bonds
Assets:
Available-for-sale securities		0
Fair value measured on recurring basis | Level 3 | Convertible promissory note
Assets:
Available-for-sale securities		1,880
Short-term investments	3,528
Fair value measured on recurring basis | Level 3 | Certificates of deposit
Assets:
Short-term investments		0
Derivative assets	0
Fair value measured on recurring basis | Level 3 | Embedded derivatives
Assets:
Derivative assets	6,329	6,755
Fair value measured on recurring basis | Level 3 | Commodity swap contracts
Liabilities:
Derivative liabilities	$ 3,723	$ 3,845