Condensed Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Revenue	$ 394.8	$ 170.5	$ 810.4	$ 538.9
Cost of revenue	339.7	138.8	688.4	447.7
Gross profit	55.1	31.7	122.0	91.2
Operating expenses:
Selling, general and administrative	44.3	33.9	120.9	109.2
Depreciation and amortization	8.9	4.5	17.6	13.3
Other operating loss	0.8	9.4	1.0	7.3
Income (loss) from operations	1.1	(16.1)	(17.5)	(38.6)
Other (expense) income:
Interest expense	(12.8)	(17.9)	(46.6)	(56.2)
Loss on early extinguishment or restructuring of debt	(0.1)	0.0	(12.5)	(9.2)
Loss from equity investees	(2.9)	(1.3)	(4.8)	(4.0)
Other income	0.6	6.9	4.4	73.0
Loss from continuing operations before income taxes	(14.1)	(28.4)	(77.0)	(35.0)
Income tax expense	(0.1)	(1.4)	(3.8)	(3.7)
Loss from continuing operations	(14.2)	(29.8)	(80.8)	(38.7)
(Loss) income from discontinued operations (including loss on sale of $200.3 million for the three months ended September 30, 2021 and net loss on sales of $159.9 million and $39.3 million for the nine months ended September 30, 2021 and 2020, respectively)	(200.3)	8.2	(149.9)	(55.4)
Net loss	(214.5)	(21.6)	(230.7)	(94.1)
Net loss attributable to noncontrolling interest and redeemable noncontrolling interest	2.6	4.3	7.9	6.8
Net loss attributable to INNOVATE Corp.	(211.9)	(17.3)	(222.8)	(87.3)
Less: Preferred dividends and deemed dividends from conversions	1.1	0.4	1.7	1.2
Net loss attributable to common stock and participating preferred stockholders	$ (213.0)	$ (17.7)	$ (224.5)	$ (88.5)
Loss per common share - continuing operations
Basic (in usd per share)	$ (0.16)	$ (0.57)	$ (0.98)	$ (1.06)
Diluted (in usd per share)	(0.16)	(0.57)	(0.98)	(1.06)
Loss per common share - discontinued operations
Basic (in usd per share)	(2.59)	0.20	(1.94)	(0.83)
Diluted (in usd per share)	(2.59)	0.20	(1.94)	(0.83)
Loss per share - Net loss attributable to common stock and participating preferred stockholders
Basic (in usd per share)	(2.75)	(0.37)	(2.92)	(1.89)
Diluted (in usd per share)	$ (2.75)	$ (0.37)	$ (2.92)	$ (1.89)
Weighted average common shares outstanding:
Basic (in shares)	77.2	47.4	77.0	46.7
Diluted (in shares)	77.2	47.4	77.0	46.7