Note 7 - Income Taxes (Detail) - Summary of deductions for intangible assets and goodwill: (USD $) In Thousands, unless otherwise specified	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
2013						$ 4,700
2014					4,800
2015				5,100
2016			5,300
2017		5,600
2018 and thereafter	38,200
	$ 63,700