SIGNIFICANT ACCOUNTING POLICIES: - Narrative (Details)		3 Months Ended
	Apr. 06, 2020 shares	Mar. 31, 2020 shares	Mar. 31, 2019 shares
Subsequent Event
Loss per hsare
Number of common stock shares issued per CSR	1.2082
Effective exchange ratio of Foamix ordinary shares into Menlo common stock	1.8006
Share options RSUs and Shares Under ESPP
Loss per hsare
Shares excluded from the computation of diluted net loss per share, because the effect of their inclusion in the computation would be anti-dilutive		5,011,179	3,327,590
Warrants
Loss per hsare
Shares excluded from the computation of diluted net loss per share, because the effect of their inclusion in the computation would be anti-dilutive		651,640