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, 2012
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than Twelve Months, Fair Value	$ 34,962
Less than 12 Months, Unrealized Losses	(93)
Twelve Months or More, Fair Value	1,014
12 Months or More, Unrealized Losses	0
Fair Value, Total	35,976
Unrealized Losses, Total	(93)
U.S. Corporate Debt Securities
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than Twelve Months, Fair Value	26,728
Less than 12 Months, Unrealized Losses	(81)
Twelve Months or More, Fair Value	1,014
12 Months or More, Unrealized Losses	0
Fair Value, Total	27,742
Unrealized Losses, Total	(81)
U.S. Government Agency Securities
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than Twelve Months, Fair Value	5,498
Less than 12 Months, Unrealized Losses	(10)
Twelve Months or More, Fair Value	0
12 Months or More, Unrealized Losses	0
Fair Value, Total	5,498
Unrealized Losses, Total	(10)
U.S. Municipal Bonds
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than Twelve Months, Fair Value	2,736
Less than 12 Months, Unrealized Losses	(2)
Twelve Months or More, Fair Value	0
12 Months or More, Unrealized Losses	0
Fair Value, Total	2,736
Unrealized Losses, Total	$ (2)