XML 22 R42.htm IDEA: XBRL DOCUMENT v3.3.1.900
Convertible Senior Notes - Carrying Values of Notes (Detail) - USD ($)
$ in Thousands
Oct. 31, 2015
Jan. 31, 2015
Convertible Senior Notes Due 2020 [Member]    
Liability component    
Principal $ 300,000  
Less: Debt discount (78,712)  
Net carrying amount 221,288  
Equity component 84,003  
Convertible Senior Notes Due 2019 [Member]    
Liability component    
Principal 350,000 $ 350,000
Less: Debt discount (52,651) (62,513)
Net carrying amount 297,349 287,487
Equity component $ 70,482 $ 70,482