Accrued and Other Current Liabilities (Tables)

12 Months Ended

Dec. 31, 2017

Payables And Accruals [Abstract]

Schedule of Accrued and Other Current Liabilities

	December 31,
	2016		2017
	(in thousands)
Employee benefits	$	8,375	$	8,269
Professional fees and settlements		613		350
Other		1,636		1,088
Total	$	10,624	$	9,707