Acquisitions, Goodwill and Other Intangible Assets Acquisitions, Goodwill and Other Intangible Assets (Details 3) $ in Thousands	12 Months Ended
	Jan. 31, 2016 USD ($)
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Gross	$ 62,360
Finite-Lived Intangible Assets, Accumulated Amortization	(14,178)
Finite-Lived Intangible Assets, Net	$ 48,182
Developed Technology Rights [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	59 months
Finite-Lived Intangible Assets, Gross	$ 59,370
Finite-Lived Intangible Assets, Accumulated Amortization	(12,088)
Finite-Lived Intangible Assets, Net	$ 47,282
Customer Relationships [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	14 months
Finite-Lived Intangible Assets, Gross	$ 1,810
Finite-Lived Intangible Assets, Accumulated Amortization	(1,288)
Finite-Lived Intangible Assets, Net	$ 522
Other Intangible Assets [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	26 months
Finite-Lived Intangible Assets, Gross	$ 1,180
Finite-Lived Intangible Assets, Accumulated Amortization	(802)
Finite-Lived Intangible Assets, Net	$ 378