Pensions and other postretirement benefit plans - Schedule of Estimated Benefit Payments (Details) $ in Thousands	Dec. 31, 2025 USD ($)
Pension benefits
Defined Benefit Plans and Other Postretirement Benefit Plans
2026	$ 112,980
2027	113,107
2028	111,222
2029	112,295
2030	108,085
Thereafter	488,002
Postretirement benefits
Defined Benefit Plans and Other Postretirement Benefit Plans
2026	4,477
2027	4,200
2028	3,943
2029	3,695
2030	3,469
Thereafter	$ 14,275

Amount of benefit for defined benefit plan expected to be paid in five fiscal years after fifth fiscal year following current fiscal year.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-5

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

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Amount of benefit for defined benefit plan expected to be paid in next fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in fourth fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in third fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in second fiscal year following current fiscal year.

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