CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 121.3	$ 139.8
Other comprehensive (loss) income:
Pension and other postretirement adjustments, net of tax	(0.1)	0.4
Cumulative translation adjustment	(64.3)	36.6
Other comprehensive (loss) income	(64.4)	37.0
Comprehensive income	56.9	176.8
Comprehensive loss attributable to noncontrolling interest	0.1	0.0
Comprehensive income attributable to IDEX	$ 57.0	$ 176.8