Notes Payable - Additional Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			12 Months Ended
	Oct. 31, 2013	Jan. 31, 2013	Oct. 31, 2012	Oct. 31, 2013	Jul. 31, 2013
Line of Credit Facility [Line Items]
Repayment of borrowing on notes payable	$ 24,000		$ 0	$ 205,000
Weighted average borrowing rate	1.3766%			1.3766%
Remaining borrowing capacity	285,000			285,000
Line of Credit Facility, Maximum Borrowing Capacity	435,000			435,000
Outstanding balance on credit facility	26,442			26,442	50,613
Proceeds from borrowing on notes payable		220,000
USD-denominated credit facility China [Member]
Line of Credit Facility [Line Items]
Remaining borrowing capacity	14,758			14,758
USD-Denominated Borrowing Credit Revolver [Member]
Line of Credit Facility [Line Items]
Notes Payable	39,000			39,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Outstanding balance on credit facility	$ 15,000			$ 15,000	$ 39,000