Fair Value of Assets and Liabilities - Assets Measured at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash equivalents	$ 427,671	$ 304,101
Investments in equity securities	9,703	10,653
Mutual funds	18,192	14,094
Total	455,566	328,848
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash equivalents	427,671	304,101
Investments in equity securities	9,703	10,653
Mutual funds	18,192	14,094
Total	455,566	328,848
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash equivalents	0	0
Investments in equity securities	0	0
Mutual funds	0	0
Total	0	0
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash equivalents	0	0
Investments in equity securities	0	0
Mutual funds	0	0
Total	$ 0	$ 0