Note 12 - Income Taxes - Effective Tax Rate Analysis and Reconciliation of Expected Statutory Rate (Details) - USD ($) $ in Thousands	3 Months Ended														12 Months Ended
	Dec. 31, 2018	[1]	Sep. 30, 2018	[2]	Jun. 30, 2018	[3],[4]	Mar. 31, 2018	[5]	Dec. 31, 2017	[6],[7]	Sep. 30, 2017	[8]	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Expected income tax provision at U.S. statutory rate															$ 1,059	$ 1,343
Increase (decrease) in tax from:
Nondeductible expenses															1,466	2,463
Domestic tax expense, net of Federal benefit															310	791
Deemed dividend from foreign subsidiaries															175	423
NOL carryforwards utilized															118	36
Foreign income tax rate differences															90	(229)
Restricted stock															67	(59)
Global intangible low taxed income															57
Current year tax credits (foreign and research)															(553)	(379)
Effective Income Tax Rate Reconciliation, Federal Transition Tax Payable, Amount															(476)	476
Section 250 foreign derived intangible income deduction															(233)
Changes in valuation allowance															(129)	17
Federal tax rate changes																(1,843)
Domestic production activities deduction																(290)
Acquisition costs																142
Other															55	(28)
Income tax expense	$ 295		$ 728		$ 382		$ 601		$ 55		$ 823		$ 891	$ 1,094	$ 2,006	$ 2,863

[1] The quarter ended December 31, 2018 includes a $2,828 increase in the fair value of contingent consideration, which was not deductible for tax purposes.

[2] The quarter ended September 30, 2018 includes $3,057 increase in the fair value of contingent consideration, which was not deductible for tax purposes.

[3] The quarter ended June 30, 2018 includes a $710 reduction in the fair value of contingent consideration, which was not taxable.

[4] The quarter ended June 30, 2018 includes the reversal of certain adjustments originally recorded in the quarter ended December 31, 2017 which were related to tax legislation enacted in December 2017, as discussed in Notes 2 and 12.

[5] The quarter ended March 31, 2018 includes a $1,726 increase in the fair value of contingent consideration, which was not deductible for tax purposes.

[6] 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.

[7] The quarter ended December 31, 2017 includes adjustments related to tax legislation enacted in December 2017, as discussed in Note 2 and 12.

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