Cash, Cash Equivalents and Marketable Securities (Details 3) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Jun. 30, 2011
Schedule of Available-for-sale Securities [Line Items]
Money market funds	$ 103,980	$ 26,979
Total cash equivalents and marketable securities	109,691	51,551
Estimate of Fair Value
Schedule of Available-for-sale Securities [Line Items]
Money market funds	103,980	26,979
US agency securities - FDIC Insured	5,711	16,025
Government agency securities		8,547
Total cash equivalents and marketable securities	109,691	51,551
Quoted Prices in Active Markets for Identical Assets (Level 1)
Schedule of Available-for-sale Securities [Line Items]
Money market funds	103,980	26,979
US agency securities - FDIC Insured
Government agency securities
Total cash equivalents and marketable securities	103,980	26,979
Significant Other Inputs (Level 2)
Schedule of Available-for-sale Securities [Line Items]
Money market funds
US agency securities - FDIC Insured	5,711	16,025
Government agency securities		8,547
Total cash equivalents and marketable securities	5,711	24,572
Significant Unobservable Inputs (Level 3)
Schedule of Available-for-sale Securities [Line Items]
Money market funds
US agency securities - FDIC Insured
Government agency securities
Total cash equivalents and marketable securities

Investment in short-term money-market instruments (such as commercial paper, banker's acceptances, repurchase agreements, government securities, certificates of deposit, and so forth) which are highly liquid (that is, readily convertible to known amounts of cash) and so near their maturity that they present an insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify as cash equivalents by definition. Original maturity means an 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.

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Debt securities issued by a United States government agency such as Government National Mortgage Association (Ginnie Mae), Federal Home Loan Mortgage Corporation (Freddie Mac), and Federal National Mortgage Association (Fannie Mae), which are short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant 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.

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