Business Combinations - Additional Information1 (Detail) (USD $)	12 Months Ended							0 Months Ended	12 Months Ended		0 Months Ended		12 Months Ended		0 Months Ended			12 Months Ended		0 Months Ended		12 Months Ended
	Jan. 31, 2014 Entity	Jan. 31, 2013 Entity	Jan. 31, 2012	Jan. 31, 2014 Minimum	Jan. 31, 2013 Minimum	Jan. 31, 2014 Maximum	Jan. 31, 2013 Maximum	Feb. 02, 2012 2Catalyze, Inc.	Jan. 31, 2014 2Catalyze, Inc.	Jan. 31, 2013 2Catalyze, Inc.	Feb. 02, 2012 2Catalyze, Inc. Developed Technology	Aug. 13, 2012 Buddy Media, Inc.	Jan. 31, 2014 Buddy Media, Inc.	Jan. 31, 2013 Buddy Media, Inc.	Aug. 13, 2012 Buddy Media, Inc. Developed Technology	Sep. 30, 2012 GoInstant, Inc.	Sep. 04, 2012 GoInstant, Inc.	Jan. 31, 2014 GoInstant, Inc.	Jan. 31, 2013 GoInstant, Inc.	Sep. 30, 2012 GoInstant, Inc. Developed Technology	Sep. 04, 2012 GoInstant, Inc. Developed Technology	Jan. 31, 2014 Other Business Combinations	Jan. 31, 2013 Other Business Combinations
Business Acquisition [Line Items]
Business acquisition date									Feb. 01, 2012				Aug. 13, 2012					Sep. 04, 2012
Fair value of consideration transferred								$ 50,636,000				$ 735,753,000					$ 50,557,000
Unvested options assumed with a fair value										2,200,000							6,200,000
Total consideration allocated to the purchase consideration										500,000		36,100,000					1,300,000
Total consideration allocated to future services										1,700,000		31,300,000					4,900,000
Closing share price	$ 60.53											$ 36.29
Share conversion ratio								0.044				0.584				0.344
Fair value of unvested options and restricted stock-based awards assumed												67,400,000
Finite-Lived Intangible Assets, Useful Life				3 years	1 year	5 years	3 years				3 years				5 years					3 years
Number of business acquired	3	5
Total purchase price paid in cash, net of cash acquired	2,617,302,000	579,745,000	422,699,000					50,166,000				497,500,000					49,221,000					31,700,000	15,100,000
Total intangible assets subject to amortization	14,600,000	4,100,000						5,970,000			4,970,000	78,340,000			65,210,000						6,560,000
Purchase Price allocation to Goodwill	20,646,000	12,410,000								45,579,000				640,534,000					45,295,000
Net tangible liabilities		300,000
Deferred tax liabilities	4,400,000	1,000,000						1,671,000				2,436,000					1,771,000
Impairment of goodwill	$ 0	$ 0	$ 0