Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2015

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, 2015.

	2015												2014
	Q1			Q2			Q3			Q4			Q1			Q2			Q3			Q4
Revenues	$	13,491		$	8,358		$	8,569		$	9,121		$	8,116		$	10,385		$	12,417		$	14,952
Expenses	$	19,712		$	20,635		$	21,254		$	24,794		$	15,727		$	17,432		$	20,071		$	19,421
Net loss	$	(5,319	)	$	(12,126	)	$	(9,245	)	$	(14,013	)	$	(7,572	)	$	(6,981	)	$	(7,545	)	$	(4,319	)
Net loss per share	$	(0.08	)	$	(0.17	)	$	(0.13	)	$	(0.20	)	$	(0.12	)	$	(0.10	)	$	(0.11	)	$	(0.06	)