Condensed Consolidated Statements of (Loss) Income (unaudited) - USD ($) shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Income Statement [Abstract]
Revenues	$ 105.5	$ 86.0	$ 253.2	$ 219.4
Other income, net	0.0	0.0	0.0	1.0
Cost of revenues	40.6	33.1	92.0	80.6
Selling, general and administrative expense	47.1	39.5	101.2	95.0
Depreciation and amortization expense	7.6	7.0	14.0	14.1
Operating income	10.2	6.4	46.0	30.7
Interest expense	10.9	12.0	28.3	24.1
Interest income	1.3	2.1	3.6	4.4
Income (loss) before income taxes	0.6	(3.5)	21.3	11.0
Provision for (benefit from) income taxes	2.0	(0.7)	7.4	2.8
Net (loss) income attributable to Emerald Holding, Inc.	(1.4)	(2.8)	13.9	8.2
Accretion to redemption value of redeemable convertible preferred stock	0.0	(2.0)	0.0	(12.7)
Net (loss) income attributable to Emerald Holding, Inc. common stockholders	$ (1.4)	$ (4.8)	$ 13.9	$ (4.5)
Basic (loss) income per share	$ (0.01)	$ (0.03)	$ 0.07	$ (0.04)
Diluted (loss) income per share	$ (0.01)	$ (0.03)	$ 0.07	$ (0.04)
Basic weighted average common shares outstanding	198,650	155,915	199,614	109,477
Diluted weighted average common shares outstanding	198,650	155,915	200,089	109,477