Share-Based Compensation (Stock Appreciation Rights Activity) (Details) - Stock Appreciation Rights	3 Months Ended
	Apr. 30, 2016 USD ($) $ / shares shares
Stock Appreciation Rights Activity, Number of Underlying Shares
Number of Underlying Shares, Beginning Balance at January 30, 2016 | shares	5,301,115
Number of Underlying Shares, Granted | shares	0
Number of Underlying Shares, Exercised | shares	(9,533)
Number of Underlying Shares, Forfeited | shares	(44,121)
Number of Underlying Shares, Ending Balance at April 30, 2016 | shares	5,247,461
Number of Underlying shares, Stock appreciation rights exercisable | shares	4,522,532
Number of Underlying Shares, Stock appreciation rights expected to become exercisable | shares	636,179
Stock Appreciation Rights, Weighted-Average Exercise Price
Weighted-Average Exercise Price, Beginning Balance at January 30, 2016 | $ / shares	$ 45.02
Weighted-Average Exercise Price, Granted | $ / shares	0.00
Weighted-Average Exercise Price, Exercised | $ / shares	22.46
Weighted-Average Exercise Price, Forfeited or expired | $ / shares	30.08
Weighted-Average Exercise Price, Ending Balance at April 30, 2016 | $ / shares	45.23
Weighted-Average Exercise Price, Stock appreciation rights exercisable | $ / shares	48.05
Weighted-Average Exercise Price, Stock appreciation rights expected to become exercisable | $ / shares	$ 28.00
Aggregate Intrinsic Value, Outstanding | $	$ 2,783,085
Aggregate Intrinsic Value, Stock appreciation rights exercisable | $	536,048
Aggregate Intrinsic Value, Stock appreciation rights expected to become exercisable | $	$ 1,886,958
Weighted-Average Remaining Contractual Life, Outstanding	3 years 4 months
Weighted-Average Remaining Contractual Life, Stock appreciation rights exercisable	2 years 6 months
Weighted Average Remaining Contractual Life, Stock appreciation rights expected to become exercisable	8 years 7 months