Supplemental Cash Flow Information (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2011
Changes in operating assets and liabilities:
Accounts receivable	$ 4,362	$ (15,569)	$ (5,536)
Inventories	8,567	(11,528)	(9,189)
Prepaid expenses and other assets	976	(291)	96
Accounts payable	(2,937)	(233)	2,713
Accrued and other liabilities	(1,709)	4,578	4,428
Customer advances	(60)	(33)	215
Other operating activites, net	9,199	(23,076)	(7,273)
Cash paid during the year for income taxes	26,697	16,782	19,700
Significant non-cash transactions:
Capital expenditures included in accounts payable	$ 2,196	$ 984	$ 2,181