Acquisitions of and Investments in Businesses and Technologies (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended			1 Months Ended	12 Months Ended					1 Months Ended		12 Months Ended			12 Months Ended		1 Months Ended							12 Months Ended	1 Months Ended
	Jan. 31, 2012 Y	Jan. 31, 2011	Jan. 31, 2010	Jan. 31, 2012 Vista Research [Member]	Jan. 31, 2012 Vista Research [Member] Y	Jan. 31, 2012 SST [Member]	Jan. 31, 2011 SST [Member]	Jan. 31, 2010 SST [Member]	Nov. 30, 2009 SST [Member]	Nov. 30, 2009 Ranchview [Member]	Jan. 31, 2012 Existing Technology [Member] Vista Research [Member]	Jan. 31, 2012 Existing Technology [Member] Ranchview [Member] Y	Nov. 30, 2009 Existing Technology [Member] Ranchview [Member]	Jan. 31, 2012 Other Intangible Assets [Member] Vista Research [Member]	Jan. 31, 2012 Other Intangible Assets [Member] Ranchview [Member] Y	Nov. 30, 2009 Other Intangible Assets [Member] Ranchview [Member]	Jan. 31, 2012 Acquisition [Member] Vista Research [Member]	Jan. 31, 2012 Acquisition [Member] Vista Research [Member]	Jan. 31, 2013 Receipt of SSRS Orders January 2013 [Member] Vista Research [Member]	Jan. 31, 2014 Receipt of SSRS Orders January 2014 [Member] Vista Research [Member]	Jan. 31, 2012 Accrued Liabilities [Member] Vista Research [Member]	Jan. 31, 2012 Other Liabilities [Member] Vista Research [Member]	Jan. 31, 2012 Maximum [Member] Guarantee of Business Revenue [Member] Vista Research [Member]	Jan. 31, 2012 Maximum [Member] Employee Bonus Pool [Member] Vista Research [Member]	Nov. 30, 2009 SST [Member] Technology Related Assets [Member] Y	Nov. 30, 2009 SST [Member] License Related Assets [Member] Y
Business Acquisition [Line Items]
Stock purchase price from business acquisition																	$ 23,269
Cash paid for in connection with business combination										1,500							12,000
Liabilities Assumed																	2,869
Acquisition-related contingent consideration	3,266	263	103							2,310								8,400			3,068	5,332
Contingent consideration to be paid in connection with business combination										4,000									3,250	3,250
Business acquisition contingent consideration payments period																								7 years
Maximum amount of contingent consideration to be paid																							15,000	15,000
Goodwill				11,497	11,497					2,734
Intangible assets related to business acquisition				7,810	7,810						4,300		900	250		175
Finite-lived intangible assets, useful life, minimum, years	3				6										5
Finite-lived intangible assets, useful lifes, maximum	20				10										7
Acquired Finite-lived Intangible Asset, Weighted Average Useful Life					4.1
Net sales from the date of acquisition				631
Operating Income (Loss)				(125)
Business Acquisition, Percentage of Voting Interests Acquired									20.00%
Total purchase price	0	0	5,000			0	0	5,000
Carrying value of equity method investment in excess of underlying net assets									$ 4,976																$ 1,054	$ 3,200
Business Acquisition, Contingent Consideration On Future Sales										6.00%
Finite-Lived Intangible Assets, Useful Life												6													7	10