Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Details 3)

v2.4.0.6
Fair Value Measurements (Details 3) (USD $)
In Thousands, unless otherwise specified
Jul. 31, 2012
Jan. 31, 2012
Cost $ 105,813 $ 92,492
Gross Unrealized Gains 104 88
Gross Unrealized Losses 0 0
Estimated Fair Value 105,917 92,580
Cash [Member]
   
Cost 90,035 74,226
Gross Unrealized Gains 0 0
Gross Unrealized Losses 0 0
Estimated Fair Value 90,035 74,226
Cash Equivalents [Member]
   
Cost 2,535 6,359
Gross Unrealized Gains 0 0
Gross Unrealized Losses 0 0
Estimated Fair Value 2,535 6,359
Cash and Cash Equivalents [Member]
   
Cost 92,570 80,585
Gross Unrealized Gains 0 0
Gross Unrealized Losses 0 0
Estimated Fair Value 92,570 80,585
US government agency issues [Member]
   
Cost 3,011 6,781
Gross Unrealized Gains 70 68
Gross Unrealized Losses 0 0
Estimated Fair Value 3,081 6,849
Corporate Debt Securities [Member]
   
Cost 0 1,000
Gross Unrealized Gains 0 6
Gross Unrealized Losses 0 0
Estimated Fair Value 0 1,006
Us Government Agency Issues Marketable Securities Short Term [Member]
   
Cost 3,011 7,781
Gross Unrealized Gains 70 74
Gross Unrealized Losses 0 0
Estimated Fair Value 3,081 7,855
Us Government Agency Issues Long Term [Member]
   
Cost 10,232 4,126
Gross Unrealized Gains 34 14
Gross Unrealized Losses 0 0
Estimated Fair Value 10,266 4,140
Us Government Agency Issues Marketable Securities Long Term [Member]
   
Cost 10,232 4,126
Gross Unrealized Gains 34 14
Gross Unrealized Losses 0 0
Estimated Fair Value $ 10,266 $ 4,140