CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 118.9	$ 209.0	$ 381.4	$ 487.3
Other comprehensive income (loss):
Pension and other postretirement adjustments, net of tax of $0.1, $—, $0.2 and $0.2, respectively	(0.1)	(0.3)	(0.4)	(0.8)
Cumulative translation adjustment	91.8	(58.1)	21.5	(19.2)
Other comprehensive income (loss), net of tax	91.7	(58.4)	21.1	(20.0)
Comprehensive income	210.6	150.6	402.5	467.3
Comprehensive loss attributable to noncontrolling interest	0.2	0.1	0.4	0.2
Comprehensive income attributable to IDEX	$ 210.8	$ 150.7	$ 402.9	$ 467.5