Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, at beginning of year	$ (16,850)		$ (17,330)
Net unrealized gains (losses) arising during the period	(630)		(2,770)
Less: Net realized gains reclassified to net income	(12,750)		(3,250)
Total other comprehensive income (loss)	12,120		480		$ 7,070
Reclassification of stranded tax effects	(1,270)
Balance, at end of year	(6,000)		(16,850)		(17,330)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax	(1,470)		3,250		1,670
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	3,300		4,110		(650)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	10,290		(6,880)		6,050
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, Tax	500
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	1,000		1,200
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax	100		900
Defined Benefit Plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, at beginning of year	(7,200)		(10,450)
Net unrealized gains (losses) arising during the period	(1,870)	[1]	0
Less: Net realized gains reclassified to net income	(400)	[2]	(3,250)	[3]
Reclassification of stranded tax effects	(1,260)
Balance, at end of year	(9,930)		(7,200)		(10,450)
Derivative Instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, at beginning of year	940		(3,170)
Net unrealized gains (losses) arising during the period	3,300	[1]	4,110	[4]
Less: Net realized gains reclassified to net income	0		0
Reclassification of stranded tax effects	(10)
Balance, at end of year	4,230		940		(3,170)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, at beginning of year	(10,590)		(3,710)
Net unrealized gains (losses) arising during the period	(2,060)		(6,880)
Less: Net realized gains reclassified to net income	(12,350)		0
Reclassification of stranded tax effects	0
Balance, at end of year	(300)		(10,590)		(3,710)
Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Total other comprehensive income (loss)	$ 12,120		$ 480		$ 7,070

[1] Defined benefit plans, net of income tax of $0.5 million. See Note 15, "Employee Benefit Plans," for additional details. Derivative instruments, net of income tax of $1.0 million. See Note 12, "Derivative Instruments," for further details.

[2] Defined benefit plans, net of income tax of $0.1 million. See Note 15, "Employee Benefit Plans," for additional details

[3] Defined benefit plans, net of income tax of $0.9 million. See Note 15, "Employee Benefit Plans," for additional details.

[4] Derivative instruments, net of income tax expense of $1.2 million. See Note 12, "Derivative Instruments," for further details.