REVENUE - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of revenue
Net sales	$ 711,850	$ 632,921
Notebooks/Mobility
Disaggregation of revenue
Net sales	199,895	174,875
Desktops
Disaggregation of revenue
Net sales	77,975	73,640
Software
Disaggregation of revenue
Net sales	69,875	71,736
Servers/Storage
Disaggregation of revenue
Net sales	53,810	55,558
Net/Com Products
Disaggregation of revenue
Net sales	55,768	47,011
Displays and Sound
Disaggregation of revenue
Net sales	58,957	57,146
Accessories
Disaggregation of revenue
Net sales	127,804	88,213
Other Hardware/Services
Disaggregation of revenue
Net sales	67,766	64,742
Business Solutions
Disaggregation of revenue
Net sales	278,785	252,932
Business Solutions | Notebooks/Mobility
Disaggregation of revenue
Net sales	91,613	80,935
Business Solutions | Desktops
Disaggregation of revenue
Net sales	33,294	26,784
Business Solutions | Software
Disaggregation of revenue
Net sales	36,398	34,688
Business Solutions | Servers/Storage
Disaggregation of revenue
Net sales	25,830	25,717
Business Solutions | Net/Com Products
Disaggregation of revenue
Net sales	21,012	22,239
Business Solutions | Displays and Sound
Disaggregation of revenue
Net sales	23,946	20,332
Business Solutions | Accessories
Disaggregation of revenue
Net sales	28,021	22,053
Business Solutions | Other Hardware/Services
Disaggregation of revenue
Net sales	18,671	20,184
Enterprise Solutions
Disaggregation of revenue
Net sales	333,418	275,635
Enterprise Solutions | Notebooks/Mobility
Disaggregation of revenue
Net sales	79,316	66,565
Enterprise Solutions | Desktops
Disaggregation of revenue
Net sales	34,209	35,969
Enterprise Solutions | Software
Disaggregation of revenue
Net sales	26,182	27,776
Enterprise Solutions | Servers/Storage
Disaggregation of revenue
Net sales	16,234	17,425
Enterprise Solutions | Net/Com Products
Disaggregation of revenue
Net sales	24,946	14,628
Enterprise Solutions | Displays and Sound
Disaggregation of revenue
Net sales	23,568	26,935
Enterprise Solutions | Accessories
Disaggregation of revenue
Net sales	90,974	56,515
Enterprise Solutions | Other Hardware/Services
Disaggregation of revenue
Net sales	37,989	29,822
Public Sector Solutions
Disaggregation of revenue
Net sales	99,647	104,354
Public Sector Solutions | Notebooks/Mobility
Disaggregation of revenue
Net sales	28,966	27,375
Public Sector Solutions | Desktops
Disaggregation of revenue
Net sales	10,472	10,887
Public Sector Solutions | Software
Disaggregation of revenue
Net sales	7,295	9,272
Public Sector Solutions | Servers/Storage
Disaggregation of revenue
Net sales	11,746	12,416
Public Sector Solutions | Net/Com Products
Disaggregation of revenue
Net sales	9,810	10,144
Public Sector Solutions | Displays and Sound
Disaggregation of revenue
Net sales	11,443	9,879
Public Sector Solutions | Accessories
Disaggregation of revenue
Net sales	8,809	9,645
Public Sector Solutions | Other Hardware/Services
Disaggregation of revenue
Net sales	$ 11,106	$ 14,736