CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 139.9	$ 112.7
Other comprehensive loss:
Reclassification adjustments for derivatives, net of tax	0.0	0.7
Pension and other postretirement adjustments, net of tax	0.6	0.8
Cumulative translation adjustment	(19.5)	(48.5)
Other comprehensive loss	(18.9)	(47.0)
Comprehensive income	121.0	65.7
Comprehensive loss attributable to noncontrolling interest	0.0	0.0
Comprehensive income attributable to IDEX	$ 121.0	$ 65.7