Cash Equivalents and Investments - Remaining Maturities (Details) $ in Millions	Jun. 30, 2020 USD ($) security	Dec. 31, 2019 USD ($) security
Investments, available-for-sale
Securities with remaining maturities greater than one year \| security	22	9
Aggregate fair value with remaining maturities greater than one year \| $	$ 128.5	$ 64.4

Fair value of investment in debt security, measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next rolling fiscal year through fifth year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

No definition available.

Name:	us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant