Cash and Cash Equivalents and Investments (Details 2) (USD $) In Thousands	Jun. 30, 2011
Gross unrealized losses of cash and cash equivalents and short-term investments
Available-for-sale securities, less than 12 months	$ 22,631
Available-for-sale securities, gross unrealized loss, less than 12 months	592
Available-for-sale securities, more than 12 months	3,147
Available-for-sale securities, gross unrealized loss, more than 12 months	153
Equity Securities [Member]
Gross unrealized losses of cash and cash equivalents and short-term investments
Available-for-sale securities, less than 12 months	1,067
Available-for-sale securities, gross unrealized loss, less than 12 months	18
Available-for-sale securities, more than 12 months	0
Available-for-sale securities, gross unrealized loss, more than 12 months	0
Corporate debt securities [Member]
Gross unrealized losses of cash and cash equivalents and short-term investments
Available-for-sale securities, less than 12 months	19,300
Available-for-sale securities, gross unrealized loss, less than 12 months	479
Available-for-sale securities, more than 12 months	0
Available-for-sale securities, gross unrealized loss, more than 12 months	0
Mortgage-CMO debt securities [Member]
Gross unrealized losses of cash and cash equivalents and short-term investments
Available-for-sale securities, less than 12 months	2,264
Available-for-sale securities, gross unrealized loss, less than 12 months	95
Available-for-sale securities, more than 12 months	117
Available-for-sale securities, gross unrealized loss, more than 12 months	4
Asset-backed debt securities [Member]
Gross unrealized losses of cash and cash equivalents and short-term investments
Available-for-sale securities, less than 12 months	0
Available-for-sale securities, gross unrealized loss, less than 12 months	0
Available-for-sale securities, more than 12 months	3,030
Available-for-sale securities, gross unrealized loss, more than 12 months	149
Debt Securities [Member]
Gross unrealized losses of cash and cash equivalents and short-term investments
Available-for-sale securities, less than 12 months	21,564
Available-for-sale securities, gross unrealized loss, less than 12 months	574
Available-for-sale securities, more than 12 months	3,147
Available-for-sale securities, gross unrealized loss, more than 12 months	$ 153