Condensed Quarterly Financial Data (Tables)

12 Months Ended

Dec. 31, 2014

Quarterly Financial Information Disclosure [Abstract]

Schedule of Condensed Quarterly Financial Data

The operating results for any quarter are not necessarily indicative of results for any future period.

	Three months ended
	March 31,			June 30,			September 30,			December 31,
	(in thousands, except per share data)
2014
Total revenue	$	8,751		$	10,881		$	12,343		$	15,618
Net loss attributable to common stockholders	$	(11,422	)	$	(14,088	)	$	(12,148	)	$	(12,380	)
Net loss per share – basic and diluted	$	(0.68	)	$	(0.78	)	$	(0.67	)	$	(0.68	)
2013
Total revenue	$	5,676		$	7,218		$	8,389		$	10,120
Net loss attributable to common stockholders	$	(9,601	)	$	(7,806	)	$	(7,700	)	$	(8,827	)
Net loss per share – basic and diluted	$	(17.88	)	$	(13.69	)	$	(0.53	)	$	(0.60	)