CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 112,672	$ 101,998
Other comprehensive income (loss):
Reclassification adjustments for derivatives, net of tax	664	1,194
Pension and other postretirement adjustments, net of tax	745	2,296
Cumulative translation adjustment	(48,439)	(26,456)
Other comprehensive income (loss)	(47,030)	(22,966)
Comprehensive income	65,642	79,032
Comprehensive (income) loss attributable to noncontrolling interest	34	0
Comprehensive income attributable to IDEX	$ 65,676	$ 79,032