Fair Value Measurements (Narrative) (Details) (USD $) In Millions, unless otherwise specified				3 Months Ended
Mar. 31, 2013 Other geographic areas	Sep. 30, 2012 Other geographic areas	Mar. 31, 2013 China	Mar. 31, 2013 Nanya Technology Corporation
Segment Reporting Information [Line Items]
Shares shold of Nanya common stock				40.5
Proceeds from sale of Nanya common stock				$ 4.7
Pre-tax gain on sale of Nanya common stock				2.1
Cash and cash equivalents, and short-term investments	$ 39.2	$ 39.3	$ 2.7

Cash includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the customer may deposit additional funds at any time and effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid Investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Short-term investments, exclusive of cash equivalents, generally consist of marketable securities intended to be sold within one year (or the normal operating cycle if longer) and may include trading securities, available-for-sale securities, or held-to-maturity securities (if maturing within one year), as applicable.

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The cash inflow associated with the sale of equity securities classified as available-for-sale securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Statement of Financial Accounting Standard (FAS)

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 Accounting Standards Codification

-Glossary Investing Activities

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

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-Name Statement of Financial Accounting Standard (FAS)

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-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.

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