Property, Plant and Equipment (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross, excluding capital leased assets		$ 395,814,000	$ 327,059,000
Accumulated depreciation		(158,824,000)	(130,814,000)
Property, plant and equipment, net, excluding capital leased assets		236,990,000	196,245,000
Construction in progress		97,863,000	117,173,000
Property, plant and equipment, net		334,853,000	313,418,000
Fixed asset impairment	$ 0	6,135,000	0	$ 0
Interest costs capitalized		6,300,000
Depreciation		29,300,000	23,700,000	$ 22,200,000
Outside the United States
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net		91,900,000	82,800,000
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross, excluding capital leased assets		17,608,000	17,846,000
Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross, excluding capital leased assets		138,126,000	106,316,000
Furniture and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross, excluding capital leased assets		$ 240,080,000	$ 202,897,000