SEGMENT REPORTING, Reportable Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2021 USD ($) Segment	Dec. 31, 2020 USD ($)	Mar. 31, 2021 USD ($)
SEGMENT REPORTING [Abstract]
Number of business segments | Segment			2
Reportable Segment Information [Abstract]
Net sales	$ 494,834	$ 427,604	$ 1,369,500	$ 1,215,716
Cost of Sales [Abstract]
Cost of sales	377,717	329,453	1,023,869	920,046
Gross profit	117,117	98,151	345,631	295,670
Selling, general, and administrative	76,874	65,390	220,153	201,746
Depreciation and amortization	3,597	3,143	11,376	10,000
Interest and financing costs	561	355	1,262	1,179
Operating expenses	81,032	68,888	232,791	212,925
Operating income	36,085	29,263	112,840	82,745
Other income (expense)	(175)	813	(377)	1,095
Earnings before tax	35,910	30,076	112,463	83,840
Net Sales [Abstract]
Contracts with customers	479,603	413,079	1,313,677	1,161,411
Financing and other	15,231	14,525	55,823	54,305
Net sales	494,834	427,604	1,369,500	1,215,716
Selected Financial Data - Statement of Cash Flow [Abstract]
Depreciation and amortization	6,576	4,302	18,620	13,762
Purchases of property, equipment and operating lease equipment	5,132	960	21,375	4,227
Selected Financial Data - Balance Sheet [Abstract]
Total assets	1,255,146	1,125,954	1,255,146	1,125,954	$ 1,076,775
Product [Member]
Reportable Segment Information [Abstract]
Net sales	432,307	375,512	1,190,524	1,066,408
Cost of Sales [Abstract]
Cost of sales	339,810	297,514	914,666	827,111
Net Sales [Abstract]
Net sales	432,307	375,512	1,190,524	1,066,408
Service [Member]
Reportable Segment Information [Abstract]
Net sales	62,527	52,092	178,976	149,308
Cost of Sales [Abstract]
Cost of sales	37,907	31,939	109,203	92,935
Net Sales [Abstract]
Net sales	62,527	52,092	178,976	149,308
Technology Segment [Member]
Reportable Segment Information [Abstract]
Net sales	476,975	415,570	1,313,634	1,176,153
Net Sales [Abstract]
Contracts with customers	473,763	411,175	1,300,643	1,157,519
Financing and other	3,212	4,395	12,991	18,634
Net sales	476,975	415,570	1,313,634	1,176,153
Operating Segments [Member] | Technology Segment [Member]
Reportable Segment Information [Abstract]
Net sales	476,975	415,570	1,313,634	1,176,153
Cost of Sales [Abstract]
Cost of sales	372,492	327,249	1,008,640	913,794
Gross profit	104,483	88,321	304,994	262,359
Selling, general, and administrative	73,413	62,377	210,369	190,519
Depreciation and amortization	3,569	3,115	11,292	9,916
Interest and financing costs	335	0	693	266
Operating expenses	77,317	65,492	222,354	200,701
Operating income	27,166	22,829	82,640	61,658
Net Sales [Abstract]
Contracts with customers	473,763	411,175	1,300,643	1,157,519
Financing and other	3,212	4,395	12,991	18,634
Net sales	476,975	415,570	1,313,634	1,176,153
Selected Financial Data - Statement of Cash Flow [Abstract]
Depreciation and amortization	3,846	3,311	12,023	10,444
Purchases of property, equipment and operating lease equipment	1,339	959	3,594	4,060
Selected Financial Data - Balance Sheet [Abstract]
Total assets	998,594	887,684	998,594	887,684
Operating Segments [Member] | Technology Segment [Member] | Product [Member]
Reportable Segment Information [Abstract]
Net sales	414,448	363,478	1,134,658	1,026,845
Cost of Sales [Abstract]
Cost of sales	334,585	295,310	899,437	820,859
Net Sales [Abstract]
Net sales	414,448	363,478	1,134,658	1,026,845
Operating Segments [Member] | Technology Segment [Member] | Service [Member]
Reportable Segment Information [Abstract]
Net sales	62,527	52,092	178,976	149,308
Cost of Sales [Abstract]
Cost of sales	37,907	31,939	109,203	92,935
Net Sales [Abstract]
Net sales	62,527	52,092	178,976	149,308
Operating Segments [Member] | Financing Segment [Member]
Reportable Segment Information [Abstract]
Net sales	17,859	12,034	55,866	39,563
Cost of Sales [Abstract]
Cost of sales	5,225	2,204	15,229	6,252
Gross profit	12,634	9,830	40,637	33,311
Selling, general, and administrative	3,461	3,013	9,784	11,227
Depreciation and amortization	28	28	84	84
Interest and financing costs	226	355	569	913
Operating expenses	3,715	3,396	10,437	12,224
Operating income	8,919	6,434	30,200	21,087
Net Sales [Abstract]
Contracts with customers	5,840	1,904	13,034	3,892
Financing and other	12,019	10,130	42,832	35,671
Net sales	17,859	12,034	55,866	39,563
Selected Financial Data - Statement of Cash Flow [Abstract]
Depreciation and amortization	2,730	991	6,597	3,318
Purchases of property, equipment and operating lease equipment	3,793	1	17,781	167
Selected Financial Data - Balance Sheet [Abstract]
Total assets	256,552	238,270	256,552	238,270
Operating Segments [Member] | Financing Segment [Member] | Product [Member]
Reportable Segment Information [Abstract]
Net sales	17,859	12,034	55,866	39,563
Cost of Sales [Abstract]
Cost of sales	5,225	2,204	15,229	6,252
Net Sales [Abstract]
Net sales	17,859	12,034	55,866	39,563
Operating Segments [Member] | Financing Segment [Member] | Service [Member]
Reportable Segment Information [Abstract]
Net sales	0	0	0	0
Cost of Sales [Abstract]
Cost of sales	0	0	0	0
Net Sales [Abstract]
Net sales	$ 0	$ 0	$ 0	$ 0