Fair Value Measurements (Tables)

9 Months Ended

Sep. 29, 2018

Fair Value Disclosures [Abstract]

Schedule of fair value of assets and liabilities measured on recurring basis

The following tables set forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):

	September 29, 2018
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	218,567	$	—	$	—	$	218,567
U.S. government agencies	—		82,734		—		82,734
Corporate debt securities	—		207,378		—		207,378
Derivative assets	—		4,681		—		4,681
Total	$	218,567	$	294,793	$	—	$	513,360
Liabilities:
Derivative liabilities	$	—	$	86	$	—	$	86
Stock warrant liability	—		—		412		412
Total	$	—	$	86	$	412	$	498

	December 31, 2017
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	193,066	$	—	$	—	$	193,066
U.S. government agencies	—		79,624		—		79,624
Corporate debt securities	—		291,582		—		291,582
Total	$	193,066	$	371,206	$	—	$	564,272
Liabilities:
Derivative liabilities	$	—	$	2,138	$	—	$	2,138
Stock warrant liability	—		—		208		208
Total	$	—	$	2,138	$	208	$	2,346