REVENUE - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Net sales	$ 6,944,827	$ 6,751,552	$ 20,079,387	$ 19,030,244
Point in time
Disaggregation of Revenue [Line Items]
Net sales	5,027,281		14,595,699
Over time
Disaggregation of Revenue [Line Items]
Net sales	1,917,546		5,483,688
HRS
Disaggregation of Revenue [Line Items]
Net sales	1,206,352		3,629,749
HRS | Point in time
Disaggregation of Revenue [Line Items]
Net sales	929,638		2,827,959
HRS | Over time
Disaggregation of Revenue [Line Items]
Net sales	276,714		801,790
CTG
Disaggregation of Revenue [Line Items]
Net sales	1,819,322		5,423,139
CTG | Point in time
Disaggregation of Revenue [Line Items]
Net sales	1,235,712		3,740,045
CTG | Over time
Disaggregation of Revenue [Line Items]
Net sales	583,610		1,683,094
IEI
Disaggregation of Revenue [Line Items]
Net sales	1,658,925		4,671,188
IEI | Point in time
Disaggregation of Revenue [Line Items]
Net sales	1,198,669		3,351,886
IEI | Over time
Disaggregation of Revenue [Line Items]
Net sales	460,256		1,319,302
CEC
Disaggregation of Revenue [Line Items]
Net sales	2,260,228		6,355,311
CEC | Point in time
Disaggregation of Revenue [Line Items]
Net sales	1,663,262		4,675,809
CEC | Over time
Disaggregation of Revenue [Line Items]
Net sales	$ 596,966		$ 1,679,502