Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2015

Fair Value Measurements

Schedule of financial assets and liabilities measured on a recurring basis

			Quoted Prices in
			Active Markets		Significant Other		Significant Other
			for Identical		Observable		Unobservable
			Assets		Inputs		Inputs
	Total		(Level 1)		(Level 2)		(Level 3)
	(in thousands)
Cash equivalents:
Money market accounts	$	42,486	$	42,486	$	—	$	—
Restricted short-term investments:
Certificates of deposit		1,285		1,285		—		—
Fair value measurement as of December 31, 2015	$	43,771	$	43,771	$	—	$	—
Cash equivalents:
Money market accounts	$	42,994	$	42,994	$	—	$	—
Restricted short-term investments:
Certificates of deposit		1,495		1,495		—		—
Fair value measurement as of December 31, 2014	$	44,489	$	44,489	$	—	$	—