Quarterly Financial Data (Tables)

12 Months Ended

Dec. 31, 2013

Quarterly Financial Information Disclosure [Abstract]

Summary of Quarterly Financial Data

The following table sets forth certain unaudited quarterly financial data for the eight quarters ended December 31, 2013.

	2013												2012
	Q1			Q2			Q3			Q4			Q1			Q2			Q3			Q4
Revenues	$	4,623		$	6,934		$	5,707		$	6,869		$	3,243		$	4,574		$	4,907		$	8,931
Expenses	$	11,528		$	12,402		$	11,866		$	15,043		$	10,526		$	10,318		$	10,709		$	12,300
Net loss	$	(6,885	)	$	(5,450	)	$	(6,145	)	$	(8,144	)	$	(7,268	)	$	(5,728	)	$	(5,790	)	$	(3,478	)
Net loss per share	$	(0.13	)	$	(0.10	)	$	(0.11	)	$	(0.13	)	$	(0.13	)	$	(0.11	)	$	(0.11	)	$	(0.07	)