Cash and Cash Equivalents, Short-term Investments and Fair Value of Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2013

Cash and Cash Equivalents [Abstract]

Schedule of Cash, Cash Equivalents and Short-term Investments [Table Text Block]

Cash and cash equivalents and short-term investments consist of the following significant investment asset classes, with disclosure of amortized cost, gross unrealized gains and losses and fair value as of June 30, 2013 and December 31, 2012 (in thousands):

	June 30, 2013
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value		Cash / Cash Equivalents		Short-term Investments		Security Classification
Cash	$	34,364	$	—	$	—	$	34,364	$	34,364	$	—	N/A
Money market funds	52,970		—		—		52,970		52,970		—		Available for sale
Total cash, cash equivalents and short-term investments	$	87,334	$	—	$	—	$	87,334	$	87,334	$	—

c	December 31, 2012
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value		Cash / Cash Equivalents		Short-term Investments		Security Classification
Cash	$	23,422	$	—	$	—	$	23,422	$	23,422	$	—	N/A
Money market funds	38,892		—		1		38,891		38,891		—		Available for sale
Total cash, cash equivalents and short-term investments	$	62,314	$	—	$	1	$	62,313	$	62,313	$	—

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

	Quoted Prices in Active Markets for Identical Instruments (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total Fair Value
At June 30, 2013
Money market funds	$	52,970	$	—	$	—	$	52,970
Total	$	52,970	$	—	$	—	$	52,970
At December 31, 2012
Money market funds	$	38,891	$	—	$	—	$	38,891
Total	$	38,891	$	—	$	—	$	38,891