Supplemental Disclosures (Tables)

12 Months Ended

Dec. 31, 2017

Payables And Accruals [Abstract]

Schedules of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consists of the following (in thousands):

	December 31, 2017		December 31, 2016
Accrued personnel costs	$	5,789	$	3,338
Accrued external general and administrative expenses		1,078		672
Accrued external research and development expenses		2,072		3,005
Accrued purchases of property and equipment		430		844
Other accrued expenses and current liabilities		236		267
	$	9,605	$	8,126