Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, at beginning of year	$ (6,000)		$ (16,850)
Net unrealized gains (losses) arising during the period	(260)		(630)
Less: Net realized gains reclassified to net income	(640)		(12,750)
Total other comprehensive income	380		12,120		$ 480
Reclassification of stranded tax effects			(1,270)
Balance, at end of year	(5,620)		(6,000)		(16,850)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax	1,310		(1,470)		3,250
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(7,810)		3,300		4,110
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	6,880		10,290		(6,880)
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, Tax	400		500
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, Tax	400		500
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	2,500		1,000
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax	200		100
Defined Benefit Plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, at beginning of year	(9,930)		(7,200)
Net unrealized gains (losses) arising during the period	670	[1]	(1,870)	[2]
Less: Net realized gains reclassified to net income	(640)	[3]	(400)	[4]
Reclassification of stranded tax effects			(1,260)
Balance, at end of year	(8,620)		(9,930)		(7,200)
Derivative Instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, at beginning of year	4,230		940
Net unrealized gains (losses) arising during the period	(7,810)	[1]	3,300	[2]
Less: Net realized gains reclassified to net income	0		0
Reclassification of stranded tax effects			(10)
Balance, at end of year	(3,580)		4,230		940
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, at beginning of year	(300)		(10,590)
Net unrealized gains (losses) arising during the period	6,880		(2,060)
Less: Net realized gains reclassified to net income	0		(12,350)
Reclassification of stranded tax effects			0
Balance, at end of year	6,580		(300)		(10,590)
Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Total other comprehensive income	$ 380		$ 12,120		$ 480

[1] Defined benefit plans, net of income tax of $0.4 million. See Note 18, "Employee Benefit Plans," for additional details. Derivative instruments, net of income tax of $2.5 million. See Note 14, "Derivative Instruments," for further details.

[2] Defined benefit plans, net of income tax of $0.5 million. See Note 18, "Employee Benefit Plans," for additional details. Derivative instruments, net of income tax expense of $1.0 million. See Note 14, "Derivative Instruments," for further details.

[3] Defined benefit plans, net of income tax of $0.2 million. See Note 18, "Employee Benefit Plans," for additional details

[4] Defined benefit plans, net of income tax of $0.1 million. See Note 18, "Employee Benefit Plans," for additional details.