Stock-Based Compensation - Schedule of Stock Options Activity (Details) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended
	Jul. 02, 2017 USD ($) $ / shares shares
Number of Shares
Balance outstanding at beginning of period, (in shares) | shares	4,979
Forfeited or expired, (in shares) | shares	(117)
Exercised (in shares) | shares	(53)
Balance outstanding at end of period, (in shares) | shares	4,809
Exercisable, (in shares) | shares	3,968
Vested and expected to vest, (in shares) | shares	4,636
Weighted Average Exercise Price
Balance outstanding at beginning of period, (in dollars per share) | $ / shares	$ 2.35
Forfeited or expired, (in dollars per share) | $ / shares	2.96
Exercised (in dollars per share) | $ / shares	1.31
Balance outstanding at end of period, (in dollars per share) | $ / shares	2.35
Exercisable, (in dollars per share) | $ / shares	2.61
Vested and expected to vest, (in dollars per share) | $ / shares	$ 2.39
Weighted Average Remaining Term
Balance outstanding	3 years 7 months 21 days
Exercisable	2 years 6 months 7 days
Vested and expected to vest	3 years 5 months 9 days
Aggregate Intrinsic Value
Balance outstanding | $	$ 656
Exercisable | $	216
Vested and expected to vest | $	$ 560