Fair Value Measurement (Tables)

12 Months Ended

Dec. 31, 2016

Fair Value Disclosures [Abstract]

Schedule of Fair Value Assets Measured on Recurring Basis

The following table presents the balances of assets measured at fair value on a recurring basis as of December 31, 2016 and 2015:

	December 31, 2016						December 31, 2015
	Level 1		Level 2		Level 3		Level 1		Level 2		Level 3
	(in thousands)
Money market funds	$	—	$	1,723	$	—	$	—	$	1,083	$	—
Commercial paper		—		131,937		—		—		113,586		—
Corporate bonds		—		16,089		—		—		41,473		—
U.S. government agency bonds		—		5,500		—		—		9,004		—
Total	$	—	$	155,249	$	—	$	—	$	165,146	$	—