Equity and Debt Securities - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Schedule Of Available For Sale And Trading Securities [Line Items]
Gross unrealized loss	$ 5.9	$ 28.8

Available for sale debt securities and equity/trading securities gross unrealized loss.

No definition available.

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Namespace Prefix:	flgt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration