Property, plant and equipment (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	$ 681,700	$ 539,600
Less: Accumulated depreciation and amortization	(171,500)	(132,400)
Total Property, plant and equipment, net	510,200	407,200
Depreciation and amortization	36,316	32,242	$ 28,023
Land and Improvements [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	44,600	21,800
Buildings, Building Improvements and Leasehold Improvements [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	216,200	160,000
Furniture and Equipment [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	293,900	206,800
Software [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	55,200	50,800
Construction-In-Progress [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	$ 71,800	$ 100,200

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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- Definition

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

+ References

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

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