Hedging Instruments (Details) (USD $) In Thousands	3 Months Ended	6 Months Ended
Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2011	Jul. 31, 2010
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	$ 1,775	$ 4,441	$ 1,750	$ 4,906
Pre-Tax Loss Recognized in Earnings on Hedged Item	(1,486)	(3,899)	(1,492)	(4,297)
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)	(518)	(1,435)	2,073	1,370
Amount of (Loss) Gain Reclassified from Accumulated OCI into Earnings (Effective Portion)	910	322	1,815	460
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)		(1)		276
Amount of (Loss) Gain Reclassified from Accumulated OCI into Earnings (Effective Portion)	213	(466)	607	(1,178)
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	(25)	(82)	(92)	(148)
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)	(51)	(1,769)	(61)	(1,416)
Amount of (Loss) Gain Reclassified from Accumulated OCI into Earnings (Effective Portion)	(701)	(692)	(1,339)	(1,507)
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	94	(99)	541	(614)
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)	(8,959)	(1,968)	(10,158)	643
Amount of (Loss) Gain Reclassified from Accumulated OCI into Earnings (Effective Portion)	(1,156)	(37)	(2,053)	(266)
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	25	82	92	148
Nondesignated [Member]
Derivative instruments gain loss recognized in Financial Statements Net
Pre-Tax (Loss) Gain Recognized in Earnings on Derivative	94	(99)	541	(614)
Cash Flow Hedging [Member]
Derivative instruments gain loss recognized in Financial Statements Net
Pre tax (loss) gain recognized in OCI (effective portion)	(9,528)	(5,173)	(8,146)	873
Amount of (Loss) Gain Reclassified from Accumulated OCI into Earnings (Effective Portion)	$ (734)	$ (873)	$ (970)	$ (2,491)

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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