REVLON, INC. BASIC AND DILUTED EARNINGS (LOSS) PER COMMON SHARE - Components of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Net loss	$ (53.1)	$ (67.7)	$ (96.0)	$ (44.5)	$ (126.8)	$ (213.9)	$ (216.8)	$ (385.2)
Denominator:
Weighted-average common shares outstanding - Basic (in shares)	54,025,861			53,476,354			53,899,732	53,371,986
Effect of dilutive restricted stock and RSUs (in shares)	0			0			0	0
Weighted-average common shares outstanding - Diluted (in shares)	54,025,861			53,476,354			53,899,732	53,371,986
Basic and Diluted (loss) earnings per common share:
Basic net loss per common share (in dollars per share)	$ (0.98)			$ (0.83)			$ (4.02)	$ (7.22)
Diluted net loss per common share (in dollars per share)	$ (0.98)			$ (0.83)			$ (4.02)	$ (7.22)
Restricted Stock and Restricted Stock Units
Basic and Diluted (loss) earnings per common share:
Unvested restricted stock and RSUs under the Stock Plan (in shares)	759,994			0			581,856	0