Fair Value Measurements (Fair Values of Financial Instruments Measured On Recurring Basis) (Details) - USD ($) $ in Thousands	Jun. 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	$ 16,059	15,699
Total assets measured at fair value	343,443	383,736
Contingent consideration	2,834	2,834
Total liabilities measured at fair value	2,834	2,834
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Consensus common stock		27,109
Investment in corporate debt securities	16,059	15,699
Total assets measured at fair value	343,443	383,736
Contingent consideration	2,834	2,834
Total liabilities measured at fair value	2,834	2,834
Money market and other funds | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	327,384	340,928
Money market and other funds | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	327,384	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	327,384	368,037
Contingent consideration	0	0
Total liabilities measured at fair value	0	0
Level 1 | Money market and other funds | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	327,384	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 | Money market and other funds | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	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	16,059	15,699
Total assets measured at fair value	16,059	15,699
Contingent consideration	2,834	2,834
Total liabilities measured at fair value	2,834	2,834
Level 3 | Money market and other funds | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	$ 0	$ 0