Investments (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	$ 1,164,179
Gross Unrealized Gains	592
Gross Unrealized Losses	(547)
Fair Value	1,164,224
Cash equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	80,766
Gross Unrealized Gains
Gross Unrealized Losses
Fair Value	80,766
Cash equivalents [Member] \| Money market funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	68,859
Gross Unrealized Gains
Gross Unrealized Losses
Fair Value	68,859
Cash equivalents [Member] \| Time deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	11,907
Gross Unrealized Gains
Gross Unrealized Losses
Fair Value	11,907
Short-term investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	677,009
Gross Unrealized Gains	443
Gross Unrealized Losses	(238)
Fair Value	677,214
Short-term investments [Member] \| Time deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	77,475
Gross Unrealized Gains
Gross Unrealized Losses	(16)
Fair Value	77,459
Short-term investments [Member] \| Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	48,250
Gross Unrealized Gains	1
Gross Unrealized Losses	(30)
Fair Value	48,221
Short-term investments [Member] \| Government and corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	551,284
Gross Unrealized Gains	442
Gross Unrealized Losses	(192)
Fair Value	551,534
Long-term investments [Member] \| Government and corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	406,404
Gross Unrealized Gains	149
Gross Unrealized Losses	(309)
Fair Value	$ 406,244

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.

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This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

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