Note 2 - Schedule of Adoption of New Revenue Standard Impacted the Consolidated Financial Statements - Income Statement (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
	Jan. 01, 2018	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Gross sales		$ 147,214	$ 134,487	$ 286,344	$ 238,198
Net revenue		152,046	134,554	293,143	239,560
Cost of goods sold		87,254	76,995	177,496	135,126
Gross profit		64,792	57,559	115,647	104,434
Operating profit		44,652	34,972	75,033	62,566
Provision for income taxes		8,748	9,174	14,534	14,986
Income from continuing operations		40,852	25,124	65,101	46,239
Net income		$ 40,419	$ 25,030	$ 64,477	$ 44,895
Income from continuing operations		$ 1.21	$ 0.75	$ 1.94	$ 1.38
Accounting Standards Updated 2014-09 [Member] | Effect of Change [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Gross sales	$ 51,896	$ 18,988		$ 56,268
Net revenue		18,988		56,268
Cost of goods sold	31,347	4,020		24,719
Gross profit		14,968		31,549
Operating profit		14,968		31,549
Provision for income taxes	$ 4,330	3,463		6,634
Income from continuing operations		11,505		24,915
Net income		$ 11,505		$ 24,915
Income from continuing operations		$ 0.34		$ 0.74
Accounting Standards Updated 2014-09 [Member] | Amount Without Adoption of ASC 606 [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Gross sales		$ 128,226		$ 230,076
Net revenue		133,058		236,875
Cost of goods sold		83,234		152,777
Gross profit		49,824		84,098
Operating profit		29,684		43,484
Provision for income taxes		5,285		7,900
Income from continuing operations		29,347		40,186
Net income		$ 28,914		$ 39,562
Income from continuing operations		$ 0.87		$ 1.20