Investments and Fair Value Measurements - Fair Value Measurements (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Assets:
Total debt securities available for sale	$ 80,865	$ 81,643
Total investment securities at fair value	116,131	116,436
Long-term investment securities at fair value	27,911	28,919
Marketable equity securities
Assets:
Total equity securities at fair value	12,785	12,724
Mutual funds invested in debt securities
Assets:
Total equity securities at fair value	22,481	22,069
U.S. government securities
Assets:
Total debt securities available for sale	797
Corporate securities
Assets:
Total debt securities available for sale	24,595
U.S. government and federal agency
Assets:
Total debt securities available for sale	25,439
Recurring
Assets:
Total investment securities at fair value	116,131	116,436
Long-term investment securities at fair value	27,911	28,919
Total	482,673	379,292
Recurring | Total equity securities at fair value
Assets:
Total equity securities at fair value	35,266	34,793
Recurring | Marketable equity securities
Assets:
Total equity securities at fair value	12,785	12,724
Recurring | Mutual funds invested in debt securities
Assets:
Total equity securities at fair value	22,481	22,069
Recurring | Total debt securities available for sale
Assets:
Total debt securities available for sale	80,865	81,643
Recurring | U.S. government securities
Assets:
Total debt securities available for sale	797	779
Recurring | Corporate securities
Assets:
Total debt securities available for sale	24,595	53,814
Recurring | U.S. government and federal agency
Assets:
Total debt securities available for sale	25,439	27,050
Recurring | Commercial paper
Assets:
Total debt securities available for sale	7,479
Recurring | Index-linked U.S. bonds
Assets:
Total debt securities available for sale	22,555
Recurring | Money market funds
Assets:
Cash and cash equivalents	266,208	155,411
Recurring | Commercial paper
Assets:
Cash and cash equivalents	48,423	54,526
Recurring | Money market funds securing legal bonds
Assets:
Cash and cash equivalents	24,000	24,000
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Total investment securities at fair value	35,266	34,793
Long-term investment securities at fair value	0	0
Total	325,474	214,204
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Total equity securities at fair value
Assets:
Total equity securities at fair value	35,266	34,793
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Marketable equity securities
Assets:
Total equity securities at fair value	12,785	12,724
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Mutual funds invested in debt securities
Assets:
Total equity securities at fair value	22,481	22,069
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Total debt securities available for sale
Assets:
Total debt securities available for sale	0	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. government securities
Assets:
Total debt securities available for sale	0	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate securities
Assets:
Total debt securities available for sale	0	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. government and federal agency
Assets:
Total debt securities available for sale	0	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial paper
Assets:
Total debt securities available for sale	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Index-linked U.S. bonds
Assets:
Total debt securities available for sale	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market funds
Assets:
Cash and cash equivalents	266,208	155,411
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial paper
Assets:
Cash and cash equivalents	0	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market funds securing legal bonds
Assets:
Cash and cash equivalents	24,000	24,000
Recurring | Significant Other Observable Inputs (Level 2)
Assets:
Total investment securities at fair value	80,865	81,643
Long-term investment securities at fair value	0	0
Total	129,288	136,169
Recurring | Significant Other Observable Inputs (Level 2) | Total equity securities at fair value
Assets:
Total equity securities at fair value	0	0
Recurring | Significant Other Observable Inputs (Level 2) | Marketable equity securities
Assets:
Total equity securities at fair value	0	0
Recurring | Significant Other Observable Inputs (Level 2) | Mutual funds invested in debt securities
Assets:
Total equity securities at fair value	0	0
Recurring | Significant Other Observable Inputs (Level 2) | Total debt securities available for sale
Assets:
Total debt securities available for sale	80,865	81,643
Recurring | Significant Other Observable Inputs (Level 2) | U.S. government securities
Assets:
Total debt securities available for sale	797	779
Recurring | Significant Other Observable Inputs (Level 2) | Corporate securities
Assets:
Total debt securities available for sale	24,595	53,814
Recurring | Significant Other Observable Inputs (Level 2) | U.S. government and federal agency
Assets:
Total debt securities available for sale	25,439	27,050
Recurring | Significant Other Observable Inputs (Level 2) | Commercial paper
Assets:
Total debt securities available for sale	7,479
Recurring | Significant Other Observable Inputs (Level 2) | Index-linked U.S. bonds
Assets:
Total debt securities available for sale	22,555
Recurring | Significant Other Observable Inputs (Level 2) | Money market funds
Assets:
Cash and cash equivalents	0	0
Recurring | Significant Other Observable Inputs (Level 2) | Commercial paper
Assets:
Cash and cash equivalents	48,423	54,526
Recurring | Significant Other Observable Inputs (Level 2) | Money market funds securing legal bonds
Assets:
Cash and cash equivalents	0	0
Recurring | Significant Unobservable Inputs (Level 3)
Assets:
Total investment securities at fair value	0	0
Long-term investment securities at fair value	0	0
Total	0	0
Recurring | Significant Unobservable Inputs (Level 3) | Total equity securities at fair value
Assets:
Total equity securities at fair value	0	0
Recurring | Significant Unobservable Inputs (Level 3) | Marketable equity securities
Assets:
Total equity securities at fair value	0	0
Recurring | Significant Unobservable Inputs (Level 3) | Mutual funds invested in debt securities
Assets:
Total equity securities at fair value	0	0
Recurring | Significant Unobservable Inputs (Level 3) | Total debt securities available for sale
Assets:
Total debt securities available for sale	0	0
Recurring | Significant Unobservable Inputs (Level 3) | U.S. government securities
Assets:
Total debt securities available for sale	0	0
Recurring | Significant Unobservable Inputs (Level 3) | Corporate securities
Assets:
Total debt securities available for sale	0	0
Recurring | Significant Unobservable Inputs (Level 3) | U.S. government and federal agency
Assets:
Total debt securities available for sale	0	0
Recurring | Significant Unobservable Inputs (Level 3) | Commercial paper
Assets:
Total debt securities available for sale	0
Recurring | Significant Unobservable Inputs (Level 3) | Index-linked U.S. bonds
Assets:
Total debt securities available for sale	0
Recurring | Significant Unobservable Inputs (Level 3) | Money market funds
Assets:
Cash and cash equivalents	0	0
Recurring | Significant Unobservable Inputs (Level 3) | Commercial paper
Assets:
Cash and cash equivalents	0	0
Recurring | Significant Unobservable Inputs (Level 3) | Money market funds securing legal bonds
Assets:
Cash and cash equivalents	$ 0	$ 0