Note B - Acquisition of Veth Propulsion Holding BV - Intangible Assets (Details) - USD ($) $ in Thousands		6 Months Ended
	Jul. 02, 2018	Dec. 28, 2018
Intangible assets, estimated fair value		$ 22,000
Intangible assets, estimated average useful lives (Year)		10 years
Customer Relationships [Member]
Intangible assets, estimated fair value		$ 12,300
Technology-Based Intangible Assets [Member]
Intangible assets, estimated fair value		8,000
Trade Names [Member]
Intangible assets, estimated fair value		$ 1,700
Veth Propulsion [Member]
Intangible assets, estimated fair value	$ 22,000
Intangible assets, annual amortization	2,338
Veth Propulsion [Member] | Customer Relationships [Member]
Intangible assets, estimated fair value	$ 12,300
Intangible assets, estimated average useful lives (Year)	12 years
Intangible assets, annual amortization	$ 1,025
Veth Propulsion [Member] | Technology-Based Intangible Assets [Member]
Intangible assets, estimated fair value	$ 8,000
Intangible assets, estimated average useful lives (Year)	7 years
Intangible assets, annual amortization	$ 1,143
Veth Propulsion [Member] | Trade Names [Member]
Intangible assets, estimated fair value	$ 1,700
Intangible assets, estimated average useful lives (Year)	10 years
Intangible assets, annual amortization	$ 170