Note 15 - Accumulated Other Comprehensive Loss - Reclassifications Out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Selling, general and administrative expenses									$ 70,468	$ 60,422	$ 57,867
Total before tax									141,825	127,539	89,565
Tax benefit									(38,061)	(40,214)	(32,389)
Amounts reclassified from accumulated other comprehensive loss	$ 40,259	$ 17,296	$ 25,030	$ 19,865	$ 37,384	$ 9,218	$ 20,494	$ 14,582	102,450	81,678	57,217
Release of currency translation adjustment										1,158	$ 15,573
Reclassification out of Accumulated Other Comprehensive Income [Member]
Amounts reclassified from accumulated other comprehensive loss									(921)	(878)
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Cost of goods sold, selling, general, and administrative expenses									(1,400)	(1,152)
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Selling, general and administrative expenses									(52)	(52)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Total before tax									(1,452)	(1,204)
Tax benefit									531	397
Amounts reclassified from accumulated other comprehensive loss									(921)	(807)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Amounts reclassified from accumulated other comprehensive loss										(71)
Release of currency translation adjustment										$ (71)