Stock-Based Compensation - Additional Information (Detail) (USD $)	12 Months Ended			0 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	May 18, 2011 Amended 2007 Plan [Member]	Dec. 31, 2013 Amended 2007 Plan [Member]	Dec. 31, 2013 Restricted Stock Units (RSUs) [Member]	Dec. 31, 2012 Restricted Stock Units (RSUs) [Member]	Dec. 31, 2011 Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Description of share based compensation under Amended 2007 Omnibus Plan	On May 18, 2011, Insight's stockholders approved the Company's Amended 2007 Omnibus Plan ("the Amended 2007 Plan") to, among other changes, increase the number of shares of common stock authorized to be issued thereunder by 3,000,000 shares to a total of 7,250,000 shares.
Stockholders approved increase in authorized shares under the Amended 2007 Omnibus Plan				3,000,000
Maximum number of authorized shares under the Amended 2007 Omnibus Plan				7,250,000	7,250,000
Number of shares of stock available for grant					4,433,643
Total compensation cost related to RSU's not yet recognized						$ 10,530,000
Weighted average number of years for recognition of outstanding nonvested RSUs						1 year 3 months 29 days
Shares withheld to cover taxes						151,521	158,231	154,473
Payments for employees' tax obligations to taxing authorities	$ 3,094,000	$ 3,288,000	$ 2,697,000			$ 3,094,000	$ 3,288,000	$ 2,697,000
Options granted	0