CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 449.3	$ 377.8	$ 425.5
Other comprehensive (loss) income:
Reclassification adjustments for derivatives, net of tax	2.5	4.6	4.9
Pension and other postretirement adjustments, net of tax	17.0	1.4	(3.1)
Cumulative translation adjustment	(75.6)	107.8	0.1
Other comprehensive (loss) income	(56.1)	113.8	1.9
Comprehensive income	393.2	491.6	427.4
Comprehensive loss attributable to noncontrolling interest	0.0	0.0	0.0
Comprehensive income attributable to IDEX	$ 393.2	$ 491.6	$ 427.4