Note 13 - Employee Retirement Plans - Obligations and Funded Status Schedule (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2015
Change in benefit obligation
Benefit obligation at beginning of year	$ 3,715,000	$ 3,809,000
Service cost	85,000	90,000	$ 82,000
Interest cost	124,000	144,000	160,000
Plan participants’ contributions	1,000	1,000
Actuarial loss (gain)	229,000	(95,000)
Other	(3,000)	(8,000)
Benefits paid	(210,000)	(188,000)
Foreign currency translation	(54,000)	(38,000)
Benefit obligation at end of year	3,887,000	3,715,000	3,809,000
Change in plan assets
Fair value of plan assets at beginning of year	3,058,000	3,263,000
Actual gain (loss) on plan assets	310,000	(108,000)
Employer contributions	125,000	116,000
Plan participants’ contributions	1,000	1,000
Benefits paid	(210,000)	(188,000)
Foreign currency translation	(59,000)	(26,000)
Fair value of plan assets at end of year	3,225,000	3,058,000	3,263,000
Funded status at end of year
Fair value of plan assets	3,058,000	3,058,000	3,263,000	$ 3,225,000	$ 3,058,000
Benefit obligations	(3,715,000)	(3,715,000)	(3,809,000)	(3,887,000)	(3,715,000)
Funded status of plans				(662,000)	(657,000)
Amounts recognized in the consolidated balance sheets consist of:
Noncurrent asset				35,000	50,000
Current liability				(18,000)	(35,000)
Noncurrent liability				(679,000)	(672,000)
Recognized liability				(662,000)	(657,000)
Amounts recognized in accumulated other comprehensive income consist of:
Net actuarial loss				348,000	332,000
Prior service cost (credit)				30,000	35,000
Amount recognized at end of year				378,000	367,000
United States Pension Plan of US Entity [Member]
Change in benefit obligation
Benefit obligation at beginning of year	3,161,000	3,222,000
Service cost	61,000	64,000	55,000
Interest cost	111,000	126,000	137,000
Plan participants’ contributions	1,000	1,000
Actuarial loss (gain)	145,000	(87,000)
Other	1,000
Benefits paid	(191,000)	(165,000)
Foreign currency translation
Benefit obligation at end of year	3,289,000	3,161,000	3,222,000
Change in plan assets
Fair value of plan assets at beginning of year	2,616,000	2,814,000
Actual gain (loss) on plan assets	235,000	(111,000)
Employer contributions	104,000	77,000
Plan participants’ contributions	1,000	1,000
Benefits paid	(191,000)	(165,000)
Foreign currency translation
Fair value of plan assets at end of year	2,765,000	2,616,000	2,814,000
Funded status at end of year
Fair value of plan assets	2,616,000	2,616,000	2,814,000	2,765,000	2,616,000
Benefit obligations	(3,161,000)	(3,161,000)	(3,222,000)	(3,289,000)	(3,161,000)
Funded status of plans				(524,000)	(545,000)
Amounts recognized in the consolidated balance sheets consist of:
Noncurrent asset
Current liability				(13,000)	(30,000)
Noncurrent liability				(511,000)	(515,000)
Recognized liability				(524,000)	(545,000)
Amounts recognized in accumulated other comprehensive income consist of:
Net actuarial loss				311,000	305,000
Prior service cost (credit)				31,000	37,000
Amount recognized at end of year				342,000	342,000
Foreign Pension Plan [Member]
Change in benefit obligation
Benefit obligation at beginning of year	554,000	587,000
Service cost	24,000	26,000	27,000
Interest cost	13,000	18,000	23,000
Plan participants’ contributions
Actuarial loss (gain)	84,000	(8,000)
Other	(4,000)	(8,000)
Benefits paid	(19,000)	(23,000)
Foreign currency translation	(54,000)	(38,000)
Benefit obligation at end of year	598,000	554,000	587,000
Change in plan assets
Fair value of plan assets at beginning of year	442,000	449,000
Actual gain (loss) on plan assets	75,000	3,000
Employer contributions	21,000	39,000
Plan participants’ contributions
Benefits paid	(19,000)	(23,000)
Foreign currency translation	(59,000)	(26,000)
Fair value of plan assets at end of year	460,000	442,000	449,000
Funded status at end of year
Fair value of plan assets	442,000	442,000	449,000	460,000	442,000
Benefit obligations	$ (554,000)	$ (554,000)	$ (587,000)	(598,000)	(554,000)
Funded status of plans				(138,000)	(112,000)
Amounts recognized in the consolidated balance sheets consist of:
Noncurrent asset				35,000	50,000
Current liability				(5,000)	(5,000)
Noncurrent liability				(168,000)	(157,000)
Recognized liability				(138,000)	(112,000)
Amounts recognized in accumulated other comprehensive income consist of:
Net actuarial loss				37,000	27,000
Prior service cost (credit)				(1,000)	(2,000)
Amount recognized at end of year				$ 36,000	$ 25,000