Note 11 - Stockholders' Equity - Option Activity for Stock Option Plans (Details) - $ / shares			12 Months Ended
	Jan. 01, 2021	Jun. 04, 2020	Dec. 31, 2022
Outstanding, options (in shares)			7,885
Outstanding, weighted average exercise price, options (in dollars per share)			$ 546.10
Outstanding, weighted average remaining contractual life, options (Year)	6 years 9 months 18 days		5 years 11 months 4 days
Granted, options (in shares)		12,567	0
Granted, weighted average exercise price, options (in dollars per share)		$ 267.30	$ 0
Expired, options (in shares)			(129)
Expired, weighted average exercise price, options (in dollars per share)			$ 7,361.38
Forfeited/cancelled, options (in shares)			(1,353)
Forfeited/cancelled, weighted average exercise price, options (in dollars per share)			$ 443.23
Outstanding, options (in shares)			6,403
Outstanding, weighted average exercise price, options (in dollars per share)			$ 430.53
Vested and expected to vest, options (in shares)			6,246
Vested and Expected to Vest, weighted average exercise price, options (in dollars per share)			$ 435.36
Vested and Expected to Vest, weighted average contractual life, options (Year)			5 years 10 months 20 days
Exercisable, options (in shares)			6,048
Exercisable, weighted average exercise price, options (in dollars per share)			$ 441.00
Exercisable, weighted average remaining contractual life, options (Year)			5 years 10 months 2 days