Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 45,875	$ 50,143
Common stock, par value	$ 0.0015	$ 0.0015
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares outstanding	35,082,183	37,379,516
Common stock, shares issued	59,245,585	59,245,585
Treasury stock, shares	24,163,402	21,866,069