Short-Term Borrowings - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2013
Short-term Debt [Line Items]
Termination date for senior, unsecured revolving credit facility	Apr. 27, 2015
Minimum [Member]
Short-term Debt [Line Items]
Commitment fee on unused revolving credit facility	0.40%
Maximum [Member]
Short-term Debt [Line Items]
Commitment fee on unused revolving credit facility	0.50%
Line of Credit
Short-term Debt [Line Items]
Term of Revolving Credit Facility	4 years
Revolving credit facility, maximum borrowing capacity	125,000
Percentage of net current account receivable included in cash and account receivable ratio	42.00%
Credit facility limits, aggregate amount available for dividend and repurchase of stock	50,000
Credit facility limits, aggregate amount available for dividend and repurchase of stock, percentage of cumulative net income	70.00%
Line of Credit | Federal Funds Rate
Short-term Debt [Line Items]
Basis spread on variable rate	0.50%
Line of Credit | One Month LIBOR
Short-term Debt [Line Items]
Basis spread on variable rate	1.00%
Line of Credit | Minimum [Member]
Short-term Debt [Line Items]
Adjusted quick ratio, lower limit	1.00
Cash and accounts receivable ratio, lower limit	1.25
Line of Credit | Minimum [Member] | LIBOR
Short-term Debt [Line Items]
Basis spread on variable rate	2.25%
Line of Credit | Minimum [Member] | Base Rate
Short-term Debt [Line Items]
Basis spread on variable rate	1.25%
Line of Credit | Maximum [Member]
Short-term Debt [Line Items]
Leverage ratio, upper limit	2.00
Senior leverage ratio, upper limit	0.90
Line of Credit | Maximum [Member] | LIBOR
Short-term Debt [Line Items]
Basis spread on variable rate	3.25%
Line of Credit | Maximum [Member] | Base Rate
Short-term Debt [Line Items]
Basis spread on variable rate	2.25%