Stock Award Plans (Stock Option Awards) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified					12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	May 31, 2010	May 31, 2009	Dec. 31, 2011 $0.96 to $5.09 [Member]	Dec. 31, 2011 $5.13 to $11.50 [Member]	Dec. 31, 2011 $12.21 to $14.75 [Member]	Dec. 31, 2011 $15.99 to $17.83 [Member]	Dec. 31, 2011 $18.40 to $20.94 [Member]
Range of Exercise Prices, Lower limit					$ 0.96	$ 5.13	$ 12.21	$ 15.99	$ 18.40
Range of Exercise Prices, Upper limit					$ 5.09	$ 11.50	$ 14.75	$ 17.83	$ 20.94
Number of Options Outstanding	3,976	7,675	3,270	4,222	879	1,234	656	487	720
Weighted-Average Exercise Price, Outstanding	$ 10.31	$ 10.46	$ 3.42	$ 5.17	$ 3.17	$ 6.60	$ 12.53	$ 16.70	$ 18.96
Number of Options Exercisable	3,499	6,434	3,270	4,222	879	1,060	634	244	682
Weighted-Average Exercise Price, Exercisable	$ 9.87	$ 9.80	$ 3.42	$ 5.17	$ 3.17	$ 6.39	$ 12.48	$ 16.74	$ 18.97

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options.

+ References

Reference 1: 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

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The weighted average price as of the beginning of the year at which grantees can acquire the shares reserved for issuance under the stock option plan.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(a)

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

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The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

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-Number 123R

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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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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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