Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jan. 31, 2018	Jan. 31, 2017
Statement of Financial Position [Abstract]
Allowance for Doubtful Accounts	$ 2,200	$ 1,800
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, authorized (in shares)	2,207,000	2,207,000
Preferred stock, issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized (in shares)	120,000,000	120,000,000
Common stock, issued (in shares)	65,497,000	64,073,000
Common stock, outstanding (in shares)	63,836,000	62,419,000
Treasury stock, (in shares)	1,661,000	1,654,000