Fair Value Measurements (Details 1) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Fair Value, Level 1
Fair Value
Cash and Cash Equivalents	$ 27,725	$ 37,499
Short-term Investments	50,767	91,077
Total Cash and Cash Equivalents and Investments	78,492	128,576
Other Long-term Liabilities	0	0
Total Liabilities	0	0
Fair Value, Level 2
Fair Value
Cash and Cash Equivalents	0	0
Short-term Investments	552	552
Total Cash and Cash Equivalents and Investments	552	552
Other Long-term Liabilities	0	0
Total Liabilities	0	0
Fair Value, Level 3
Fair Value
Cash and Cash Equivalents	0	0
Short-term Investments	0	0
Total Cash and Cash Equivalents and Investments	0	0
Other Long-term Liabilities	29,300	27,710
Total Liabilities	29,300	27,710
Fair Value, Total
Fair Value
Cash and Cash Equivalents	27,725	37,499
Short-term Investments	51,319	91,629
Total Cash and Cash Equivalents and Investments	79,044	129,128
Other Long-term Liabilities	29,300	27,710
Total Liabilities	$ 29,300	$ 27,710