Cash, Cash Equivalents And Short-Term Investments (Unrealized Gains And Losses Related To Short-Term Investments Designated As Available-For-Sale) (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Adjusted Cost	$ 339,300	$ 354,035
Gross Unrealized Gain	214	158
Gross Unrealized Loss	(283)	(121)
Cumulative Translation Adjustment	(3,348)	(3,410)
Fair Value	335,883	350,662
Cash [Member]
Adjusted Cost	96,845	86,344
Gross Unrealized Gain	0	0
Gross Unrealized Loss	0	0
Cumulative Translation Adjustment	0	0
Fair Value	96,845	86,344
Money Market Accounts [Member]
Adjusted Cost	99,666	133,103
Gross Unrealized Gain	0	0
Gross Unrealized Loss	0	0
Cumulative Translation Adjustment	0	0
Fair Value	99,666	133,103
Municipal Bonds [Member]
Adjusted Cost	15,421	16,843
Gross Unrealized Gain	20	18
Gross Unrealized Loss	0	0
Cumulative Translation Adjustment	0	0
Fair Value	15,441	16,861
Corporate Bonds [Member]
Adjusted Cost	77,456	56,141
Gross Unrealized Gain	1	38
Gross Unrealized Loss	(276)	(69)
Cumulative Translation Adjustment	0	0
Fair Value	77,181	56,110
U.S. Treasuries And Agencies [Member]
Adjusted Cost	11,026	23,142
Gross Unrealized Gain	0	13
Gross Unrealized Loss	(7)	(20)
Cumulative Translation Adjustment	0	0
Fair Value	11,019	23,135
Foreign Government Bonds [Member]
Adjusted Cost	36,135	36,010
Gross Unrealized Gain	193	89
Gross Unrealized Loss	0	(32)
Cumulative Translation Adjustment	(3,348)	(3,410)
Fair Value	32,980	32,657
Time Deposits [Member]
Adjusted Cost	2,751	2,452
Gross Unrealized Gain	0	0
Gross Unrealized Loss	0	0
Cumulative Translation Adjustment	0	0
Fair Value	$ 2,751	$ 2,452

Accumulated adjustment, net of tax, that results from the process of translating subsidiary financial statements and foreign equity investments into the reporting currency from the functional currency of the reporting entity, net of reclassification of realized foreign currency translation gains or losses.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 830

-SubTopic 30

-Section 45

-Paragraph 12

-URI http://asc.fasb.org/extlink&oid=6915805&loc=d3e32022-110900

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 130

-Paragraph 17, 18, 19, 22, 23, 24, 25, 26

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 13

-URI http://asc.fasb.org/extlink&oid=6920043&loc=d3e653-108580

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 45

-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 Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 14

-URI http://asc.fasb.org/extlink&oid=6920043&loc=d3e681-108580

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

-Paragraph 10

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 830

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-Section 50

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Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 52

-Paragraph 31

-Subparagraph 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 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 52

-Paragraph 12, 13

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=6920043&loc=d3e637-108580

+ Details

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

+ References+ Details