Note 2 - Business Acquisitions - Preliminary Allocation of Intangible Assets (Details) - Kita Manufacturing Co. LTD. and Kita USA, Inc. [Member] $ in Millions	Jan. 04, 2017 USD ($)
Finite-lived intangible assets, estimated fair value	$ 2.1
Developed Technology Rights [Member]
Finite-lived intangible assets, estimated fair value	$ 0.7
Finite-lived intangible assets, average useful life (Year)	8 years
Customer Relationships [Member]
Finite-lived intangible assets, estimated fair value	$ 0.6
Finite-lived intangible assets, average useful life (Year)	4 years
Noncompete Agreements [Member]
Finite-lived intangible assets, estimated fair value	$ 0.3
Finite-lived intangible assets, average useful life (Year)	10 years
Order or Production Backlog [Member]
Finite-lived intangible assets, estimated fair value	$ 0.1
Finite-lived intangible assets, average useful life (Year)	1 year
Trade Names [Member]
Finite-lived intangible assets, estimated fair value	$ 0.4
Finite-lived intangible assets, average useful life (Year)	5 years