Investments and Fair Value Measurements - Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Purchase option liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability	$ 5,100	$ 8,500
Level 3 | Money market funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Money market funds	0	0
Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	12,561	48,823
Fair Value, Recurring | Money market funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Money market funds	12,041	9,752
Fair Value, Recurring | Restricted Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	24,446	35,117
Fair Value, Recurring | Commercial paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1,198
Fair Value, Recurring | Commercial paper | Restricted Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	2,646	5,432
Fair Value, Recurring | Corporate notes/bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	6,374	14,360
Fair Value, Recurring | U.S. treasuries
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	4,989	34,463
Fair Value, Recurring | U.S. treasuries | Restricted Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	21,800	29,685
Fair Value, Recurring | Contingent consideration
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability	10,250	10,890
Fair Value, Recurring | Convertible notes payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability	29,080	69,803
Fair Value, Recurring | Purchase option liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability	5,060	8,534
Fair Value, Recurring | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Recurring | Level 1 | Money market funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Money market funds	12,041	9,752
Fair Value, Recurring | Level 1 | Restricted Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Recurring | Level 1 | Commercial paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	0
Fair Value, Recurring | Level 1 | Commercial paper | Restricted Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Recurring | Level 1 | Corporate notes/bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Recurring | Level 1 | U.S. treasuries
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	0
Fair Value, Recurring | Level 1 | U.S. treasuries | Restricted Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Recurring | Level 1 | Contingent consideration
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability	0	0
Fair Value, Recurring | Level 1 | Convertible notes payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability	0	0
Fair Value, Recurring | Level 1 | Purchase option liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability	0	0
Fair Value, Recurring | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	12,561	48,823
Fair Value, Recurring | Level 2 | Money market funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Money market funds	0	0
Fair Value, Recurring | Level 2 | Restricted Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	24,446	35,117
Fair Value, Recurring | Level 2 | Commercial paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1,198
Fair Value, Recurring | Level 2 | Commercial paper | Restricted Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	2,646	5,432
Fair Value, Recurring | Level 2 | Corporate notes/bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	6,374	14,360
Fair Value, Recurring | Level 2 | U.S. treasuries
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	4,989	34,463
Fair Value, Recurring | Level 2 | U.S. treasuries | Restricted Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	21,800	29,685
Fair Value, Recurring | Level 2 | Contingent consideration
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability	0	0
Fair Value, Recurring | Level 2 | Convertible notes payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability	0	0
Fair Value, Recurring | Level 2 | Purchase option liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability	0	0
Fair Value, Recurring | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Recurring | Level 3 | Restricted Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Recurring | Level 3 | Commercial paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	0
Fair Value, Recurring | Level 3 | Commercial paper | Restricted Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Recurring | Level 3 | Corporate notes/bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Recurring | Level 3 | U.S. treasuries
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	0
Fair Value, Recurring | Level 3 | U.S. treasuries | Restricted Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	0	0
Fair Value, Recurring | Level 3 | Contingent consideration
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability	10,250	10,890
Fair Value, Recurring | Level 3 | Convertible notes payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability	29,080	69,803
Fair Value, Recurring | Level 3 | Purchase option liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability	$ 5,060	$ 8,534