Stock-Based Compensation - Schedule of Stock Options Activity (Details) shares in Thousands	9 Months Ended
	Sep. 29, 2019 $ / shares shares
Number of Shares
Balance outstanding at beginning of period, (in shares) | shares	3,201
Forfeited or expired, (in shares) | shares	(580)
Exercised (in shares) | shares	(4)
Balance outstanding at end of period, (in shares) | shares	2,617
Exercisable, (in shares) | shares	2,433
Vested and expected to vest, (in shares) | shares	2,603
Weighted Average Exercise Price
Balance outstanding at beginning of period, (in dollars per share) | $ / shares	$ 2.18
Forfeited or expired, (in dollars per share) | $ / shares	1.70
Exercised (in dollars per share) | $ / shares	0.78
Balance outstanding at end of period, (in dollars per share) | $ / shares	2.29
Exercisable, (in dollars per share) | $ / shares	2.40
Vested and expected to vest, (in dollars per share) | $ / shares	$ 2.30
Weighted Average Remaining Term
Balance outstanding	3 years 8 months 12 days
Exercisable	3 years 5 months 15 days
Vested and expected to vest	3 years 8 months 8 days