CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 139.8	$ 139.9
Other comprehensive income (loss):
Pension and other postretirement adjustments, net of tax	0.4	0.6
Cumulative translation adjustment	36.6	(19.5)
Other comprehensive income (loss)	37.0	(18.9)
Comprehensive income	176.8	121.0
Comprehensive loss attributable to noncontrolling interest	0.0	0.0
Comprehensive income attributable to IDEX	$ 176.8	$ 121.0