Note 13 - Retirement Benefit Plans - Changes in Benefit Obligations and Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair value of plan assets at end of year	$ 0
Pension Plan [Member]
Fair value of plan assets at beginning of year	13,300
Fair value of plan assets at end of year		$ 13,300
Postretirement Health Coverage [Member]
Benefit obligation at beginning of year	7,300	7,800
Service cost	100	100	$ 0
Interest cost	100	200	300
Actuarial loss (gain)	600	(300)
Foreign exchange	0	0
Settlement	0	0
Benefits paid	(1,100)	(500)
Benefit obligation at end of year	7,000	7,300	7,800
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Employer contributions	1,000	500
Foreign exchange	0	0
Settlement	0	0
Benefits paid	(1,000)	(500)
Fair value of plan assets at end of year	0	0	0
Funded status at end of year	(7,000)	(7,300)
Noncurrent other assets	0	0
Current liabilities	(700)	(700)
Long-term liabilities	(6,300)	(6,600)
Net accrued liability	(7,000)	(7,300)
Prior service cost	0	0
Net actuarial (loss) gain	200	800
Accumulated other comprehensive (loss) income	200	800
UNITED STATES | Pension Plan [Member]
Service cost	0	0	0
Interest cost	100	0	100
UNITED STATES | Nonqualified Plan [Member]
Benefit obligation at beginning of year	1,200	1,300
Service cost	0	0
Interest cost	100	0
Actuarial loss (gain)	0	0
Foreign exchange	0	0
Settlement	0	0
Benefits paid	(200)	(100)
Benefit obligation at end of year	1,100	1,200	1,300
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Employer contributions	100	100
Foreign exchange	0	0
Settlement	0	0
Benefits paid	(100)	(100)
Fair value of plan assets at end of year	0	0	0
Funded status at end of year	(1,100)	(1,200)
Noncurrent other assets	0	0
Current liabilities	(100)	(100)
Long-term liabilities	(1,000)	(1,100)
Net accrued liability	(1,100)	(1,200)
Prior service cost	0	0
Net actuarial (loss) gain	(900)	(900)
Accumulated other comprehensive (loss) income	(900)	(900)
Foreign Plan [Member] | Pension Plan [Member]
Benefit obligation at beginning of year	17,600	15,700
Service cost	0	0	0
Interest cost	200	200	300
Actuarial loss (gain)	(600)	1,700
Foreign exchange	(400)	800
Settlement	(300)	0
Benefits paid	(300)	(800)
Benefit obligation at end of year	16,200	17,600	15,700
Fair value of plan assets at beginning of year	13,300	12,200
Actual return on plan assets	(400)	600
Employer contributions	800	900
Foreign exchange	(200)	400
Settlement	(300)	0
Benefits paid	(300)	(800)
Fair value of plan assets at end of year	12,900	13,300	$ 12,200
Funded status at end of year	(3,300)	(4,300)
Noncurrent other assets	1,400	1,100
Current liabilities	(200)	0
Long-term liabilities	(4,500)	(5,400)
Net accrued liability	(3,300)	(4,300)
Prior service cost	(200)	(200)
Net actuarial (loss) gain	(2,100)	(2,000)
Accumulated other comprehensive (loss) income	$ (2,300)	$ (2,200)