Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2013

Summary of Significant Accounting Policies

Schedule of non-controlling interest in subsidiary

(in thousands)	Non-Controlling Interest
Balance at December 31, 2011	$	574
Net loss attributable to Silver Creek	(352		)
Balance at September 30, 2012	$	222

	Non-Controlling Interest (Deficit)
Balance at December 31, 2012	$	97
Net loss attributable to Silver Creek	(471		)
Balance at September 30, 2013	$	(374	)

Schedule of available-for-sale securities, all of which have maturities of twelve months or less

	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
	(in thousands)
September 30, 2013:
Certificate of deposit	$	960	$	—	$	—		$	960
Commercial paper	34,483		9		(5		)	34,487
Corporate debt securities	41,607		—		(20		)	41,587
Total	$	77,050	$	9	$	(25	)	$	77,034

Schedule of available-for-sale securities in an unrealized loss position

	Aggregate Fair Value		Unrealized Losses
	(in thousands)
September 30, 2013:
Commercial paper	$	18,485	$	(5	)
Corporate debt securities	40,587		(20		)
	$	59,072	$	(25	)