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Fair Value Measurements (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands | Jun. 30, 2022 | Dec. 31, 2021
--- | --- | ---
Debt Securities, Available-for-sale | $ 1,115,079 | $ 1,090,058
Fair Value, Inputs, Level 1 |  |
Debt Securities, Available-for-sale | 64,859 | 25,019
Fair Value, Inputs, Level 2 |  |
Debt Securities, Available-for-sale | 1,050,220 | 1,065,039
Cash Equivalents |  |
Cash Equivalents | 301,836 | 268,349
Cash Equivalents | Fair Value, Inputs, Level 1 |  |
Cash Equivalents | 64,859 | 25,019
Cash Equivalents | Fair Value, Inputs, Level 2 |  |
Cash Equivalents | 236,977 | 243,330
Cash Equivalents | Money Market Funds |  |
Cash Equivalents | 64,859 | 25,019
Cash Equivalents | Money Market Funds | Fair Value, Inputs, Level 1 |  |
Cash Equivalents | 64,859 | 25,019
Cash Equivalents | Money Market Funds | Fair Value, Inputs, Level 2 |  |
Cash Equivalents | 0 | 0
Cash Equivalents | Commercial paper |  |
Cash Equivalents | 193,710 | 179,455
Cash Equivalents | Commercial paper | Fair Value, Inputs, Level 1 |  |
Cash Equivalents | 0 | 0
Cash Equivalents | Commercial paper | Fair Value, Inputs, Level 2 |  |
Cash Equivalents | 193,710 | 179,455
Cash Equivalents | Municipal debt securities |  |
Cash Equivalents | 43,267 | 63,875
Cash Equivalents | Municipal debt securities | Fair Value, Inputs, Level 1 |  |
Cash Equivalents | 0 | 0
Cash Equivalents | Municipal debt securities | Fair Value, Inputs, Level 2 |  |
Cash Equivalents | 43,267 | 63,875
Short-term Investments |  |
Debt Securities, Available-for-sale | 813,243 | 819,478
Short-term Investments | Fair Value, Inputs, Level 1 |  |
Debt Securities, Available-for-sale | 0 | 0
Short-term Investments | Fair Value, Inputs, Level 2 |  |
Debt Securities, Available-for-sale | 813,243 | 819,478
Short-term Investments | Commercial paper |  |
Debt Securities, Available-for-sale | 462,917 | 419,469
Short-term Investments | Commercial paper | Fair Value, Inputs, Level 1 |  |
Debt Securities, Available-for-sale | 0 | 0
Short-term Investments | Commercial paper | Fair Value, Inputs, Level 2 |  |
Debt Securities, Available-for-sale | 462,917 | 419,469
Short-term Investments | Municipal debt securities |  |
Debt Securities, Available-for-sale | 103,272 | 165,573
Short-term Investments | Municipal debt securities | Fair Value, Inputs, Level 1 |  |
Debt Securities, Available-for-sale | 0 | 0
Short-term Investments | Municipal debt securities | Fair Value, Inputs, Level 2 |  |
Debt Securities, Available-for-sale | 103,272 | 165,573
Short-term Investments | Federal agency debt securities |  |
Debt Securities, Available-for-sale | 51,356 | 0
Short-term Investments | Federal agency debt securities | Fair Value, Inputs, Level 1 |  |
Debt Securities, Available-for-sale | 0 | 0
Short-term Investments | Federal agency debt securities | Fair Value, Inputs, Level 2 |  |
Debt Securities, Available-for-sale | 51,356 | 0
Short-term Investments | Corporate debt securities |  |
Debt Securities, Available-for-sale | 195,698 | 234,436
Short-term Investments | Corporate debt securities | Fair Value, Inputs, Level 1 |  |
Debt Securities, Available-for-sale | 0 | 0
Short-term Investments | Corporate debt securities | Fair Value, Inputs, Level 2 |  |
Debt Securities, Available-for-sale | 195,698 | 234,436
Long Term Investments |  |
Debt Securities, Available-for-sale | 0 | 2,231
Long Term Investments | Fair Value, Inputs, Level 1 |  |
Debt Securities, Available-for-sale | 0 | 0
Long Term Investments | Fair Value, Inputs, Level 2 |  |
Debt Securities, Available-for-sale | $ 0 | 2,231
Long Term Investments | US Treasury Bond Securities |  |
Debt Securities, Available-for-sale |  | 2,231
Long Term Investments | US Treasury Bond Securities | Fair Value, Inputs, Level 2 |  |
Debt Securities, Available-for-sale |  | $ 2,231

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- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(6)) -URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 45 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=124260329&loc=d3e26610-111562 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27161-111563 + Details
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- Definition Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References No definition available. + Details
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