Shareholders' Equity - Stock Based Compensation - Additional Information (Detail)	12 Months Ended
	Jan. 31, 2015 OptionPlan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock-based incentive plans	2
Maximum number of shares of the Company's common stock that was available for award grants under the Performance Plan	2,702,092
Stock-based awards vesting period	1 year
Period in which stock option expires under condition	3 months
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term of options and stock appreciation rights under the Performance Plan	4 years
Period in which stock option expires under condition one	10 years
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term of options and stock appreciation rights under the Performance Plan	3 years
Period in which stock option expires under condition one	7 years
Performance Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares of the Company's common stock that was available for award grants under the Performance Plan	2,702,092
Termination date of the Performance Plan	Mar. 22, 2015
Performance Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term of options and stock appreciation rights under the Performance Plan	10 years
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option expiration conditions	Expire in seven to ten years or three months after termination of employment with the Company