Short-Term Investments (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Gross unrealized gains	$ 1.0
Gross unrealized losses		$ 0.2
Mutual funds
Estimated fair value	$ 88.3	$ 100.8

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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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
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-Name Accounting Standards Codification
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