Accumulated Other Comprehensive Loss (Reclassifications Out of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020		Jun. 30, 2019		Jun. 30, 2020	Jun. 30, 2019
Schedule of Reclassifciations Out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) before income taxes	$ 7,832		$ 40,408		$ (44,742)	$ 20,818
Income tax provision (benefit)	12,200		(10,997)		13,664	(5,555)
Net income (loss)	20,032		29,411		(31,078)	15,263
Reclassifications Out of Accumulated Other Comprehensive Income (Loss)
Schedule of Reclassifciations Out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss)	1,638	[1]	(171)	[1]	2,194	11,460
Reclassifications Out of Accumulated Other Comprehensive Income (Loss) | Defined Benefit Plan Items
Schedule of Reclassifciations Out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior-service cost	(228)	[1],[2]	(228)	[1],[2]	(456)	(456)
Income (loss) before income taxes	(228)	[1]	(228)	[1]	(456)	(456)
Income tax provision (benefit)	57	[1]	57	[1]		114
Net income (loss)	(171)	[1]	(171)	[1]	(342)	(342)
Reclassifications Out of Accumulated Other Comprehensive Income (Loss) | Cash Flow Hedges
Schedule of Reclassifciations Out of Accumulated Other Comprehensive Income [Line Items]
Interest payments	2,412		0		3,381	182
Income (loss) before income taxes	2,412	[1]	0	[1]	3,381	182
Income tax provision (benefit)	(603)	[1]	0	[1]	(845)	(46)
Net income (loss)	$ 1,809	[1]	0	[1]	$ 2,536	136
Reclassifications Out of Accumulated Other Comprehensive Income (Loss) | Foreign Currency Translation Adjustment
Schedule of Reclassifciations Out of Accumulated Other Comprehensive Income [Line Items]
Realized loss on pre-existing investment			0			(11,666)
Income (loss) before income taxes			0	[1]		11,666
Income tax provision (benefit)			0	[1]		0
Net income (loss)			$ 0	[1]		$ 11,666

[1] Amounts in parentheses indicate credits to profit/loss

[2] This accumulated other comprehensive loss component is included in the computation of net periodic benefit cost.