Stock Option Plans (Details) (USD $)	6 Months Ended
	Jul. 31, 2013	Jul. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in Shares)	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	$ 500,000	$ 1,800,000
Deferred Tax Expense from Stock Options Exercised	200,000	300,000
Treasury Stock, Shares, Acquired (in Shares)		32,935
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price (in Dollars per share)	$ 12.63	$ 32.53
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 0