Hedging Instruments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Oct. 31, 2011	Oct. 31, 2010	Oct. 31, 2011	Oct. 31, 2010
Nondesignated [Member]
Derivative instruments gain loss recognized in Financial Statements Net
Pre-Tax (Loss) Gain Recognized in Earnings on Derivative	$ (124)	$ (201)	$ 417	$ (815)
Cash Flow Hedging [Member]
Derivative instruments gain loss recognized in Financial Statements Net
Pre tax (loss) gain recognized in OCI (effective portion)	(11,716)	(5,530)	(19,862)	(4,657)
Amount of (Loss) Gain Reclassified from Accumulated OCI into Earnings (Effective Portion)	(1,696)	(501)	(2,666)	(2,992)
Interest Rate Swap [Member] \| Fair Value Hedging [Member] \| Interest and other expenses, net [Member]
Derivative instruments gain loss recognized in Financial Statements Net
Pre-Tax Gain Recognized in Earnings on Derivatives	1,845	2,351	3,595	7,257
Pre-Tax Loss Recognized in Earnings on Hedged Item	(1,551)	(2,037)	(3,043)	(6,334)
Precious Metal Forward Contracts [Member] \| Cash Flow Hedging [Member] \| Cost of sales [Member]
Derivative instruments gain loss recognized in Financial Statements Net
Pre tax (loss) gain recognized in OCI (effective portion)	(6,915)	1,744	(4,842)	3,114
Amount of (Loss) Gain Reclassified from Accumulated OCI into Earnings (Effective Portion)	903	504	2,718	964
Precious Metal Collars [Member] \| Cash Flow Hedging [Member] \| Cost of sales [Member]
Derivative instruments gain loss recognized in Financial Statements Net
Pre tax (loss) gain recognized in OCI (effective portion)		385		661
Amount of (Loss) Gain Reclassified from Accumulated OCI into Earnings (Effective Portion)		(117)	607	(1,295)
Put Option [Member] \| Nondesignated [Member] \| Cost of sales [Member]
Derivative instruments gain loss recognized in Financial Statements Net
Pre-Tax (Loss) Gain Recognized in Earnings on Derivative		(195)	(92)	(343)
Put Option [Member] \| Cash Flow Hedging [Member] \| Cost of sales [Member]
Derivative instruments gain loss recognized in Financial Statements Net
Pre tax (loss) gain recognized in OCI (effective portion)	(17)	(847)	(78)	(2,263)
Amount of (Loss) Gain Reclassified from Accumulated OCI into Earnings (Effective Portion)	(426)	(577)	(1,765)	(2,084)
Foreign Exchange Forward [Member] \| Nondesignated [Member] \| Interest and other expenses, net [Member]
Derivative instruments gain loss recognized in Financial Statements Net
Pre-Tax (Loss) Gain Recognized in Earnings on Derivative	(124)	(161)	417	(775)
Foreign Exchange Forward [Member] \| Cash Flow Hedging [Member] \| Cost of sales [Member]
Derivative instruments gain loss recognized in Financial Statements Net
Pre tax (loss) gain recognized in OCI (effective portion)	(4,784)	(6,812)	(14,942)	(6,169)
Amount of (Loss) Gain Reclassified from Accumulated OCI into Earnings (Effective Portion)	(2,173)	(311)	(4,226)	(577)
Call Option [Member] \| Nondesignated [Member] \| Cost of sales [Member]
Derivative instruments gain loss recognized in Financial Statements Net
Pre-Tax (Loss) Gain Recognized in Earnings on Derivative		$ 155	$ 92	$ 303

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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The amount of net gains and losses recognized in income during the period on derivative instruments designated and qualifying as hedging instruments in fair value hedges and related hedged items designated and qualifying in fair value hedges, on derivative instruments designated and qualifying as hedging instruments in cash flow hedges, and on derivative instruments not designated as hedging instruments.

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- Definition

The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

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- Definition

The amount of gain recognized in income during the period on derivative instruments designated and qualifying as hedging instruments in fair value hedges and related hedged items designated and qualifying in fair value hedges, on derivative instruments designated and qualifying as hedging instruments in cash flow hedges, and on derivative instruments not designated as hedging instruments.

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- Definition

The amount of loss recognized in income during the period on derivative instruments designated and qualifying as hedging instruments in fair value hedges and related hedged items designated and qualifying in fair value hedges, on derivative instruments designated and qualifying as hedging instruments in cash flow hedges, and on derivative instruments not designated as hedging instruments.

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