Fair Value Measurements (Fair Values of Financial Instruments Measured On Recurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Consensus common stock		$ 27,100
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Consensus common stock		27,109
Investment in corporate debt securities	$ 16,529	15,699
Total assets measured at fair value	66,097	383,736
Contingent consideration	2,834	2,834
Total liabilities measured at fair value	2,834	2,834
Fair Value | Money market and other funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Money market and other funds	49,568	340,928
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Consensus common stock		27,109
Investment in corporate debt securities	16,529	15,699
Total assets measured at fair value	66,097	383,736
Contingent consideration	2,834	2,834
Total liabilities measured at fair value	2,834	2,834
Carrying Value | Money market and other funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Money market and other funds	49,568	340,928
Level 1 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Consensus common stock		27,109
Investment in corporate debt securities	0	0
Total assets measured at fair value	49,568	368,037
Contingent consideration	0	0
Total liabilities measured at fair value	0	0
Level 1 | Fair Value | Money market and other funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Money market and other funds	49,568	340,928
Level 2 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Consensus common stock		0
Investment in corporate debt securities	0	0
Total assets measured at fair value	0	0
Contingent consideration	0	0
Total liabilities measured at fair value	0	0
Level 2 | Fair Value | Money market and other funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Money market and other funds	0	0
Level 3 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Consensus common stock		0
Investment in corporate debt securities	16,529	15,699
Total assets measured at fair value	16,529	15,699
Contingent consideration	2,834	2,834
Total liabilities measured at fair value	2,834	2,834
Level 3 | Fair Value | Money market and other funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Money market and other funds	$ 0	$ 0