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Basis of Presentation and Summary of Significant Accounting Policies (Schedule of Unrealized Losses and Fair Values by Investment Category and Time in Continuous Unrealized Loss Position) (Details) (USD $) In Thousands, unless otherwise specified | Jun. 30, 2013
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Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract] |
Less than Twelve Months, Fair Value | $ 60,782
Less than 12 Months, Unrealized Losses | (390)
Twelve Months or More, Fair Value | 1,048
12 Months or More, Unrealized Losses | (4)
Fair Value, Total | 61,830
Unrealized Losses, Total | (394)
U.S. Corporate Debt Securities |
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract] |
Less than Twelve Months, Fair Value | 60,782
Less than 12 Months, Unrealized Losses | (390)
Twelve Months or More, Fair Value | 1,048
12 Months or More, Unrealized Losses | (4)
Fair Value, Total | 61,830
Unrealized Losses, Total | $ (394)

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