Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Details 2)

v2.4.0.6
Fair Value Measurements (Details 2) (USD $)
In Thousands, unless otherwise specified
Apr. 30, 2013
Jan. 31, 2013
Amortized Cost $ 121,346 $ 119,911
Gross Unrealized Gains 34 83
Gross Unrealized Losses 0 0
Estimated Fair Value 121,380 119,994
Cash [Member]
   
Amortized Cost 105,525 104,109
Gross Unrealized Gains 0 0
Gross Unrealized Losses 0 0
Estimated Fair Value 105,525 104,109
Cash Equivalents [Member]
   
Amortized Cost 3,664 2,612
Gross Unrealized Gains 0 0
Gross Unrealized Losses 0 0
Estimated Fair Value 3,664 2,612
Cash and Cash Equivalents [Member]
   
Amortized Cost 109,189 106,721
Gross Unrealized Gains 0 0
Gross Unrealized Losses 0 0
Estimated Fair Value 109,189 106,721
Us Government Agency Issues Short Term [Member]
   
Amortized Cost 5,030 6,043
Gross Unrealized Gains 7 61
Gross Unrealized Losses 0 0
Estimated Fair Value 5,037 6,104
Us Government Agency Issues Long Term [Member]
   
Amortized Cost 7,127 7,147
Gross Unrealized Gains 27 22
Gross Unrealized Losses 0 0
Estimated Fair Value 7,154 7,169
Corporate Debt Securities Short Term [Member]
   
Amortized Cost 0 0
Gross Unrealized Gains 0 0
Gross Unrealized Losses 0 0
Estimated Fair Value 0 0
Marketable Securities Short Term [Member]
   
Amortized Cost 5,030 6,043
Gross Unrealized Gains 7 61
Gross Unrealized Losses 0 0
Estimated Fair Value 5,037 6,104
Marketable Securities Long Term [Member]
   
Amortized Cost 7,127 7,147
Gross Unrealized Gains 27 22
Gross Unrealized Losses 0 0
Estimated Fair Value $ 7,154 $ 7,169