ACQUISITIONS - (Details) - USD ($) $ in Thousands			6 Months Ended
	Oct. 11, 2016	May 27, 2016	Jun. 30, 2016	Jun. 30, 2017	Dec. 31, 2016
Components of purchase price:
Goodwill				$ 73,602	$ 73,602
Purchase price at closing, net of cash acquired			$ 33,983
Softmart
Components of purchase price:
Current assets		$ 22,812
Fixed assets		343
Goodwill		14,314
Total assets acquired		48,769
Acquired liabilities		(16,252)
Net assets acquired		32,517
Less cash acquired		(628)
Purchase price at closing, net of cash acquired		31,889
Softmart | Customer relationships
Components of purchase price:
Intangible asset		11,300
GlobalServe
Components of purchase price:
Current assets	$ 1,486
Fixed assets	4,609
Goodwill	8,012
Total assets acquired	15,007
Acquired liabilities	(734)
Deferred taxes, unrecognized tax benefits	(2,390)
Net assets acquired	11,883
Less cash acquired	(782)
Purchase price at closing, net of cash acquired	11,101
GlobalServe | Customer relationships
Components of purchase price:
Intangible asset	900
Selling, General and Administrative Expenses | Softmart
Acquisition
Transaction costs related to acquisition					357
Selling, General and Administrative Expenses | GlobalServe
Acquisition
Transaction costs related to acquisition					$ 118
Small and Medium Sized Businesses (SMB) | Softmart
Components of purchase price:
Goodwill related to acquisition deductible for tax purposes		7,366
Large Account | Softmart
Components of purchase price:
Goodwill related to acquisition deductible for tax purposes		$ 6,948
Large Account | GlobalServe
Components of purchase price:
Goodwill	8,012
Goodwill related to acquisition deductible for tax purposes	$ 0