Common Stock Repurchases (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			6 Months Ended
	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Jan. 31, 2016
Share-Based Compensation Arrangement By Share-Based Payment Award, Options Exercisable [Abstract]
Options Exercised				100,000
Weighted Average Exercise Price				$ 17.42
Common Stock [Member]
Share-Based Compensation Arrangement By Share-Based Payment Award, Options Exercisable [Abstract]
Options Exercised	200,000	139,690	201,333
Weighted Average Exercise Price	$ 12.02	$ 20.27	$ 19.59
Shares Net Settled for Exercise	66,602	76,021	124,621
Shares Withheld for Taxes(1)	52,158	20,656	35,416
Net Shares to Employees	81,240	43,013	41,296
Weighted Average Share Price for Withholding	$ 36.08	$ 37.27	$ 31.65
Tax Withholdings (in 000s)	$ 1,882	$ 770	$ 1,121