Share Based Compensation - Weighted average assumptions by grant year (Details) (USD $)	12 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012
Share-based Compensation [Abstract]
Risk-free interest rate	0.59%	0.86%	0.67%
Expected dividend yield	1.46%	1.33%	1.20%
Expected volatility factor	41.39%	49.62%	51.44%
Expected option term (in years)	3 years 9 months	3 years 9 months	4 years
Weighted average grant date fair value (in usd per share)	$ 9.34	$ 10.92	$ 11.05