Series A Redeemable Convertible Preferred Stock Series A Redeemable Convertible Preferred Stock - Probability and Volatility Assumptions (Details)	12 Months Ended
Dec. 31, 2019
Equity [Abstract]
Probability of redemption as part of a fundamental sale transaction	0.50%
Probability of redemption absent a fundamental sale transaction	4.75%
Annual volatility	65.00%

Probability of Redemption Absent a Fundamental Sale Transaction, Percent

No definition available.

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Namespace Prefix:	falc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration