XML 50 R36.htm IDEA: XBRL DOCUMENT v3.3.1.900
Marketable Securities and Fair Value Measurements - Amortized Cost and Estimated Fair Value of Marketable Securities by Contractual Maturity (Details) - USD ($)
$ in Thousands
Jan. 31, 2016
Jan. 31, 2015
Jan. 31, 2014
Investments Debt And Equity Securities [Abstract]      
Amortized Cost, Less than one year $ 5,560    
Amortized Cost, Due in one to five years 1,821    
Amortized Cost 7,381    
Estimated Fair Value, Less than one year 5,559    
Estimated Fair Value, Due in one to five years 1,820    
Marketable securities $ 7,379 $ 0 $ 0