SEGMENT REPORTING, Reportable Segment Information (Details)
$ in Thousands
 12 Months Ended
Mar. 31, 2021
USD ($)
Segment
Mar. 31, 2020
USD ($)
Mar. 31, 2019
USD ($)
SEGMENT REPORTING [Abstract]      
Number of business segment | Segment 2    
Reportable Segment Information [Abstract]      
Net sales $ 1,568,323 $ 1,588,404 $ 1,372,673
Cost of Sales [Abstract]      
Cost of sales 1,174,769 1,197,213 1,042,285
Gross profit 393,554 391,191 330,388
Selling, general, and administrative expenses 271,263 279,182 237,082
Depreciation and amortization 13,951 14,156 11,824
Interest and financing costs 2,005 2,574 1,948
Operating expenses 287,219 295,912 250,854
Operating income 106,335 95,279 79,534
Other income 571 680 6,696
Earnings before tax 106,906 95,959 86,230
Net Sales [Abstract]      
Contracts with customers 1,496,473 1,519,096 1,311,982
Financing and other 71,850 69,308 60,691
Net sales 1,568,323 1,588,404 1,372,673
Selected Financial Data - Statement of Cash Flow [Abstract]      
Depreciation and amortization 19,991 19,156 18,639
Purchases of property, equipment and operating lease equipment 11,513 7,009 11,629
Selected Financial Data - Balance Sheet [Abstract]      
Total assets 1,076,775 909,113 786,198
Product [Member]      
Reportable Segment Information [Abstract]      
Net sales 1,366,158 1,395,288 1,223,195
Cost of Sales [Abstract]      
Cost of sales 1,049,677 1,076,773 952,464
Net Sales [Abstract]      
Net sales 1,366,158 1,395,288 1,223,195
Service [Member]      
Reportable Segment Information [Abstract]      
Net sales 202,165 193,116 149,478
Cost of Sales [Abstract]      
Cost of sales 125,092 120,440 89,821
Net Sales [Abstract]      
Net sales 202,165 193,116 149,478
Technology Segment [Member]      
Reportable Segment Information [Abstract]      
Net sales 1,507,954 1,530,138 1,329,520
Net Sales [Abstract]      
Contracts with customers 1,484,104 1,514,507 1,308,405
Financing and other 23,850 15,631 21,115
Net sales 1,507,954 1,530,138 1,329,520
Operating Segments [Member] | Technology Segment [Member]      
Reportable Segment Information [Abstract]      
Net sales 1,507,954 1,530,138 1,329,520
Cost of Sales [Abstract]      
Cost of sales 1,161,719 1,189,550 1,034,858
Gross profit 346,235 340,588 294,662
Selling, general, and administrative expenses 256,210 264,123 226,112
Depreciation and amortization 13,839 14,016 11,812
Interest and financing costs 521 294 0
Operating expenses 270,570 278,433 237,924
Operating income 75,665 62,155 56,738
Net Sales [Abstract]      
Contracts with customers 1,484,104 1,514,507 1,308,405
Financing and other 23,850 15,631 21,115
Net sales 1,507,954 1,530,138 1,329,520
Selected Financial Data - Statement of Cash Flow [Abstract]      
Depreciation and amortization 14,568 14,516 12,661
Purchases of property, equipment and operating lease equipment 4,752 4,842 6,042
Selected Financial Data - Balance Sheet [Abstract]      
Total assets 828,576 709,854 607,998
Operating Segments [Member] | Technology Segment [Member] | Product [Member]      
Reportable Segment Information [Abstract]      
Net sales 1,305,789 1,337,022 1,180,042
Cost of Sales [Abstract]      
Cost of sales 1,036,627 1,069,110 945,037
Net Sales [Abstract]      
Net sales 1,305,789 1,337,022 1,180,042
Operating Segments [Member] | Technology Segment [Member] | Service [Member]      
Reportable Segment Information [Abstract]      
Net sales 202,165 193,116 149,478
Cost of Sales [Abstract]      
Cost of sales 125,092 120,440 89,821
Net Sales [Abstract]      
Net sales 202,165 193,116 149,478
Operating Segments [Member] | Financing Segment [Member]      
Reportable Segment Information [Abstract]      
Net sales 60,369 58,266 43,153
Cost of Sales [Abstract]      
Cost of sales 13,050 7,663 7,427
Gross profit 47,319 50,603 35,726
Selling, general, and administrative expenses 15,053 15,059 10,970
Depreciation and amortization 112 140 12
Interest and financing costs 1,484 2,280 1,948
Operating expenses 16,649 17,479 12,930
Operating income 30,670 33,124 22,796
Net Sales [Abstract]      
Contracts with customers 12,369 4,589 3,577
Financing and other 48,000 53,677 39,576
Net sales 60,369 58,266 43,153
Selected Financial Data - Statement of Cash Flow [Abstract]      
Depreciation and amortization 5,423 4,640 5,978
Purchases of property, equipment and operating lease equipment 6,761 2,167 5,587
Selected Financial Data - Balance Sheet [Abstract]      
Total assets 248,199 199,259 178,200
Operating Segments [Member] | Financing Segment [Member] | Product [Member]      
Reportable Segment Information [Abstract]      
Net sales 60,369 58,266 43,153
Cost of Sales [Abstract]      
Cost of sales 13,050 7,663 7,427
Net Sales [Abstract]      
Net sales 60,369 58,266 43,153
Operating Segments [Member] | Financing Segment [Member] | Service [Member]      
Reportable Segment Information [Abstract]      
Net sales 0 0 0
Cost of Sales [Abstract]      
Cost of sales 0 0 0
Net Sales [Abstract]      
Net sales $ 0 $ 0 $ 0