Significant Accounting Policies Significant Accounting Policies - Fair Value of Liabilities (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 31, 2018	Jan. 31, 2017	Aug. 16, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Royalty liability	$ 2,469	$ 2,351
Warrants exercisable (in shares)			1,200,000
Exercise price (in USD per share)			$ 3.99
Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Royalty liability	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Royalty liability	0	0
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Royalty liability	2,469	2,351
Warrant
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants liability	0	46
Warrant | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants liability	0	0
Warrant | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants liability	0	0
Warrant | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants liability	$ 0	$ 46
Common Stock Warrant
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants exercisable (in shares)	1,400,000
Exercise price (in USD per share)	$ 4.00
Private Placement | Common Stock Warrant
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants exercisable (in shares)			1,200,000
Exercise price (in USD per share)			$ 3.99