Stockholders' Equity - Stock Options Outstanding and Exercisable (Details) - $ / shares	12 Months Ended
	Jan. 02, 2021	Dec. 28, 2019
Stock options outstanding and exercisable
Options Outstanding, Weighted Average Exercise Price	$ 7.23	$ 9.20
Range One
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	1.70
Range of Exercise Prices, Upper Range Limit	$ 2.12
Options Outstanding, Number of Shares	32,400
Options Outstanding, Weighted Average Remaining Contractual Life (years)	6 years 3 days
Options Outstanding, Weighted Average Exercise Price	$ 1.85
Options Vested and Exercisable, Number of Shares Exercisable	5,018
Options Vested and Exercisable, Weighted Average Exercise Price	$ 1.82
Range Two
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	2.13
Range of Exercise Prices, Upper Range Limit	$ 2.13
Options Outstanding, Number of Shares	434,950
Options Outstanding, Weighted Average Remaining Contractual Life (years)	6 years 8 months 1 day
Options Outstanding, Weighted Average Exercise Price	$ 2.13
Range Three
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	2.18
Range of Exercise Prices, Upper Range Limit	$ 4.33
Options Outstanding, Number of Shares	174,200
Options Outstanding, Weighted Average Remaining Contractual Life (years)	5 years 8 months 23 days
Options Outstanding, Weighted Average Exercise Price	$ 2.75
Options Vested and Exercisable, Number of Shares Exercisable	41,016
Options Vested and Exercisable, Weighted Average Exercise Price	$ 3.12
Range Four
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	4.60
Range of Exercise Prices, Upper Range Limit	$ 4.85
Options Outstanding, Number of Shares	30,000
Options Outstanding, Weighted Average Remaining Contractual Life (years)	5 years 3 months 10 days
Options Outstanding, Weighted Average Exercise Price	$ 4.73
Options Vested and Exercisable, Number of Shares Exercisable	12,813
Options Vested and Exercisable, Weighted Average Exercise Price	$ 4.72
Range Five
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	4.92
Range of Exercise Prices, Upper Range Limit	$ 4.92
Options Outstanding, Number of Shares	600,000
Options Outstanding, Weighted Average Remaining Contractual Life (years)	5 years 4 months 17 days
Options Outstanding, Weighted Average Exercise Price	$ 4.92
Options Vested and Exercisable, Number of Shares Exercisable	237,500
Options Vested and Exercisable, Weighted Average Exercise Price	$ 4.92
Range Six
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	4.98
Range of Exercise Prices, Upper Range Limit	$ 8.29
Options Outstanding, Number of Shares	168,100
Options Outstanding, Weighted Average Remaining Contractual Life (years)	4 years 4 months 9 days
Options Outstanding, Weighted Average Exercise Price	$ 5.76
Options Vested and Exercisable, Number of Shares Exercisable	98,921
Options Vested and Exercisable, Weighted Average Exercise Price	$ 5.94
Range Seven
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	8.33
Range of Exercise Prices, Upper Range Limit	$ 11.16
Options Outstanding, Number of Shares	174,428
Options Outstanding, Weighted Average Remaining Contractual Life (years)	2 years 1 month 24 days
Options Outstanding, Weighted Average Exercise Price	$ 9.67
Options Vested and Exercisable, Number of Shares Exercisable	162,989
Options Vested and Exercisable, Weighted Average Exercise Price	$ 9.69
Range Eight
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	12.85
Range of Exercise Prices, Upper Range Limit	$ 12.85
Options Outstanding, Number of Shares	15,000
Options Outstanding, Weighted Average Remaining Contractual Life (years)	2 years 9 months 21 days
Options Outstanding, Weighted Average Exercise Price	$ 12.85
Options Vested and Exercisable, Number of Shares Exercisable	15,000
Options Vested and Exercisable, Weighted Average Exercise Price	$ 12.85
Range Nine
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	14.61
Range of Exercise Prices, Upper Range Limit	$ 14.61
Options Outstanding, Number of Shares	20,000
Options Outstanding, Weighted Average Remaining Contractual Life (years)	3 years 2 months 4 days
Options Outstanding, Weighted Average Exercise Price	$ 14.61
Options Vested and Exercisable, Number of Shares Exercisable	18,751
Options Vested and Exercisable, Weighted Average Exercise Price	$ 14.61
Range Ten
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	16.29
Range of Exercise Prices, Upper Range Limit	$ 16.29
Options Outstanding, Number of Shares	462
Options Outstanding, Weighted Average Remaining Contractual Life (years)	2 years 6 months 21 days
Options Outstanding, Weighted Average Exercise Price	$ 16.29
Options Vested and Exercisable, Number of Shares Exercisable	462
Options Vested and Exercisable, Weighted Average Exercise Price	$ 16.29
Range Eleven
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	1.70
Range of Exercise Prices, Upper Range Limit	$ 16.29
Options Outstanding, Number of Shares	1,649,540
Options Outstanding, Weighted Average Remaining Contractual Life (years)	5 years 3 months 7 days
Options Outstanding, Weighted Average Exercise Price	$ 4.67
Options Vested and Exercisable, Number of Shares Exercisable	592,470
Options Vested and Exercisable, Weighted Average Exercise Price	$ 6.76