Note 11 - Income Taxes - Effective Tax Rate Analysis and Reconciliation of Expected Statutory Rate (Details) - USD ($) $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 31, 2017	[1],[2]	Sep. 30, 2017	[3]	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Expected income tax provision at U.S. statutory rate											$ 1,343	$ 1,430
Federal tax rate changes											(1,843)
Current year tax credits (foreign and research)											(379)	(140)
Domestic production activities deduction											(290)	(112)
Foreign income tax rate differences											(229)	(258)
Restricted stock											(59)
Nondeductible expenses											2,463	14
Domestic tax expense, net of Federal benefit											791	55
Effective Income Tax Rate Reconciliation, Federal Transition Tax Payable, Amount											476
Deemed dividend from foreign subsidiaries											423	396
Acquisition costs											142
NOL carryforwards utilized											36	180
Changes in valuation allowance											17	(15)
Other											(28)	(1)
Income tax expense	$ 55		$ 823		$ 891	$ 1,094	$ 612	$ 631	$ 263	$ 43	$ 2,863	$ 1,549

[1] The quarter ended December 31, 2017 includes a $7,525 increase in the fair value of contingent consideration, which was not deductible for tax purposes.

[2] The quarter ended December 31, 2017 includes adjustments related to tax legislation enacted in December 2017, as discussed in Note 2 and 11.

[3] The quarter ended September 30, 2017 includes a $549 reduction in the fair value of contingent consideration, which was not taxable.