Segment Information - Schedule of Segment Information for Entity's Continuing Operations (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Net sales		$ 404,933	$ 336,801	$ 1,179,763	$ 997,129
Gross profit		60,143	45,199	161,214	141,880
Depreciation and amortization expense	[1]	3,170	2,645	9,085	7,929
Operating profit (loss)		956	1,149	(3,401)	11,158
Commercial [Member]
Segment Reporting Information [Line Items]
Net sales		317,614	249,628	904,202	758,134
Gross profit		49,225	37,944	133,184	119,282
Depreciation and amortization expense	[1]	924	569	2,473	1,784
Operating profit (loss)		15,836	12,851	41,273	44,724
Public Sector [Member]
Segment Reporting Information [Line Items]
Net sales		68,572	64,017	210,843	151,320
Gross profit		8,664	4,923	21,317	13,727
Depreciation and amortization expense	[1]	111	9	219	35
Operating profit (loss)		3,773	1,756	9,153	4,376
MacMall [Member]
Segment Reporting Information [Line Items]
Net sales		18,757	23,164	64,740	87,693
Gross profit		2,239	2,285	6,702	8,835
Depreciation and amortization expense	[1]	18	19	54	99
Operating profit (loss)		464	(228)	606	868
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Net sales		(10)	(8)	(22)	(18)
Gross profit		15	47	11	36
Depreciation and amortization expense	[1]	2,117	2,048	6,339	6,011
Operating profit (loss)		$ (19,117)	$ (13,230)	$ (54,433)	$ (38,810)

[1] Primary fixed assets relating to network and servers are managed by the Corporate headquarters. As such, depreciation expense relating to such assets is included as part of Corporate & Other.