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Summary Of Significant Accounting Policies (Narrative) (Details) (USD $) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2011 | Mar. 31, 2010 | Mar. 31, 2012 D M | Mar. 31, 2011 | Mar. 31, 2010
Product Warranty [Line Items] |  |  |  |  |
Losses (recoveries) of commitments to purchase materials |  | $ 38,800,000 |  |  |
Inventory write-down |  |  | 4,357,000 | 63,882,000 |
Benefit to cost of revenues |  |  | 800,000 |  |
Losses On Purchase Commitments |  |  | (1,299,000) | 38,763,000 |
Adverse purchase commitments |  |  | 25,894,000 | 38,763,000 |
Potential loss, minimum |  |  | 0 |  |
Potential loss, maximum |  |  | 4,000,000 |  |
Maximum period for hedging intercompany sales of inventory, in months |  |  | 15 |  |
Forecast period for cash flow hedge accounting to be deemed as ineffective, in days |  |  | 60 |  |
Impairment charge | 1,700,000 |  |  |  |
Business Exit Costs |  |  | 2,200,000 |  |
Payments received from customers |  |  | 5,200,000 |  |
Percentage of tax benefit likely to be realized upon ultimate settlement |  |  | 50.00% |  |
Common equivalent shares not included in the calculation of diluted EPS |  |  | 2,290,416 | 2,631,251 | 688,300
Net foreign currency transaction and hedging gains (losses) |  |  | $ 3,100,000 | $ 8,000,000 | $ (2,500,000)
Minimum [Member] |  |  |  |  |
Product Warranty [Line Items] |  |  |  |  |
Warranty period, in years |  |  | 1 |  |
Maximum [Member] |  |  |  |  |
Product Warranty [Line Items] |  |  |  |  |
Warranty period, in years |  |  | 3 |  |

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- Definition Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Antidilution -URI http://asc.fasb.org/extlink&oid=6505113 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 171 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 40 -Subparagraph c -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 13, 14 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 07-4 -Paragraph 4 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Diluted Earnings Per Share -URI http://asc.fasb.org/extlink&oid=6510752 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Contingent Stock Agreement -URI http://asc.fasb.org/extlink&oid=6508534 + Details
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