Note 13 - Employee Retirement Plans - Benefit Obligation and Funded Status (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension Plan [Member] | UNITED STATES
Benefit obligation at beginning of year	$ 4,203,000	$ 3,856,000
Service cost	102,000	92,000	$ 76,000
Interest cost	78,000	110,000	133,000
Plan participants’ contributions		1,000
Plan amendments		1,000
Actuarial (gain) loss	(107,000)	329,000
Other		8,000
Benefits paid	(201,000)	(194,000)
Benefit obligation at end of year	4,075,000	4,203,000	3,856,000
Balance	3,575,000	3,153,000
Actual gain (loss) on plan assets	208,000	420,000
Defined Benefit Plan, Plan Assets, Contributions by Employer	16,000	195,000
Plan participants’ contributions		1,000
Benefits paid	(201,000)	(194,000)
Balance	3,598,000	3,575,000	3,153,000
Fair value of plan assets	3,598,000	3,575,000	3,153,000
Benefit obligations	4,075,000	4,203,000	3,856,000
Funded status of plans	(477,000)	(628,000)
Current liability	(15,000)	(13,000)
Noncurrent liability	(462,000)	(615,000)
Recognized liability	(477,000)	(628,000)
Net actuarial loss (gain)	272,000	387,000
Prior service cost (credit)	22,000	26,000
Amounts recognized at end of year	294,000	413,000
Pension Plan [Member] | Foreign Plan [Member]
Benefit obligation at beginning of year	778,000	725,000
Service cost	25,000	26,000	25,000
Interest cost	10,000	12,000	15,000
Actuarial (gain) loss	(17,000)	29,000
Other	(2,000)	(37,000)
Benefits paid	(26,000)	(19,000)
Foreign currency translation	(32,000)	42,000
Benefit obligation at end of year	736,000	778,000	725,000
Balance	598,000	518,000
Actual gain (loss) on plan assets	(2,000)	49,000
Defined Benefit Plan, Plan Assets, Contributions by Employer	31,000	50,000
Benefits paid	(26,000)	(44,000)
Foreign currency translation	(17,000)	25,000
Balance	584,000	598,000	518,000
Fair value of plan assets	584,000	598,000	518,000
Benefit obligations	736,000	778,000	725,000
Funded status of plans	(152,000)	(180,000)
Noncurrent asset	100,000	99,000
Current liability	(7,000)	(7,000)
Noncurrent liability	(245,000)	(272,000)
Recognized liability	(152,000)	(180,000)
Net actuarial loss (gain)	(3,000)	7,000
Prior service cost (credit)	1,000	1,000
Amounts recognized at end of year	(2,000)	8,000
Other Postretirement Benefits Plan [Member]
Benefit obligation at beginning of year	764,000	705,000
Service cost	10,000	9,000	9,000
Interest cost	15,000	20,000	27,000
Plan participants’ contributions	7,000	8,000
Actuarial (gain) loss	(105,000)	58,000
Other		2,000
Benefits paid	(37,000)	(38,000)
Benefit obligation at end of year	654,000	764,000	705,000
Balance	30,000
Defined Benefit Plan, Plan Assets, Contributions by Employer	9,000	60,000
Plan participants’ contributions	7,000	8,000
Benefits paid	(37,000)	(38,000)
Balance	9,000	30,000
Fair value of plan assets	9,000	30,000
Benefit obligations	654,000	764,000	$ 705,000
Funded status of plans	(645,000)	(734,000)
Current liability	(23,000)	(7,000)
Noncurrent liability	(622,000)	(727,000)
Recognized liability	(645,000)	(734,000)
Net actuarial loss (gain)	(22,000)	86,000
Prior service cost (credit)	(20,000)	(26,000)
Amounts recognized at end of year	(42,000)	60,000
Other Postretirement Benefits Plan [Member] | UNITED STATES
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 0	$ 30,000