Accumulated Other Comprehensive Loss (Details) - USD ($)	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 706,871,000	$ 693,756,000	$ 211,749,000
Other comprehensive income (loss), net of tax	16,470,000	(57,121,000)	33,929,000
ASU 2018-02 adoption		0
Ending balance	682,798,000	706,871,000	693,756,000
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(155,697,000)	(76,151,000)	(110,080,000)
Other comprehensive income (loss), net of tax	16,470,000	(57,121,000)	33,929,000
ASU 2018-02 adoption		(22,425,000)
Ending balance	(139,227,000)	(155,697,000)	(76,151,000)
Unrecognized components of employee benefit plans
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(135,590,000)	(81,638,000)	(110,080,000)
Other comprehensive gain (loss) before reclassifications	(8,119,000)	(53,278,000)	26,050,000
Income tax on other comprehensive loss	2,413,000	12,160,000	(5,731,000)
Income tax on reclassifications	(4,711,000)	(2,705,000)	(4,471,000)
Other comprehensive income (loss), net of tax	8,952,000	(31,527,000)	28,442,000
ASU 2018-02 adoption	0	(22,425,000)	0
Ending balance	(126,638,000)	(135,590,000)	(81,638,000)
Pension settlement loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reclassifications to earnings	8,787,000	0	0
Amortization of losses
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reclassifications to earnings	9,889,000	11,877,000	11,984,000
Amortization of prior service costs
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reclassifications to earnings	693,000	572,000	763,000
Amortization of negative plan amendment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reclassifications to earnings	0	(153,000)	(153,000)
Unrealized gain on derivative
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(11,622,000)	619,000	0
Other comprehensive gain (loss) before reclassifications	12,822,000	(22,985,000)	749,000
Income tax on other comprehensive loss	(3,076,000)	5,372,000	(130,000)
Reclassifications to earnings			0
Income tax on reclassifications	(1,761,000)	(1,254,000)	0
Other comprehensive income (loss), net of tax	12,912,000	(12,241,000)	619,000
Ending balance	1,290,000	(11,622,000)	619,000
Foreign currency translation adjustments
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(8,485,000)	4,868,000	0
Other comprehensive income (loss), net of tax	(5,394,000)	(13,353,000)	4,868,000
Ending balance	(13,879,000)	(8,485,000)	4,868,000
Tax effects of foreign translation adjustment	0	0	0
Interest rate swaps \| Unrealized gain on derivative
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reclassifications to earnings	(688,000)	(64,000)	0
Foreign exchange contracts \| Unrealized gain on derivative
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reclassifications to earnings	$ 5,615,000	$ 6,690,000	$ 0

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Amount before tax and reclassification adjustments of other comprehensive income (loss).

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