Acquisitions and dispositions - Acquisitions, Fair Value of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill	$ 1,429,346	$ 1,309,167
TEQ
Business Acquisition [Line Items]
Trade Accounts Receivable	11,781
Inventories	4,262
Property, Plant and Equipment	42,005
Goodwill	75,595
Other intangible assets	56,170
Payable to suppliers	(4,965)
Other net tangible assets/(liabilities)	3,243
Deferred income taxes, net	(799)
Net assets	187,292
Corenso
Business Acquisition [Line Items]
Trade Accounts Receivable	8,673
Inventories	8,707
Property, Plant and Equipment	36,928
Goodwill	43,427
Other intangible assets	29,170
Payable to suppliers	(5,963)
Other net tangible assets/(liabilities)	405
Deferred income taxes, net	(10,713)
Net assets	$ 110,634