Property, Plant and Equipment, Net - Schedule of Components (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment, Net
Property, plant and equipment, net	$ 333,310	$ 313,418
Land and land improvements
Property, Plant and Equipment, Net
Property, plant, and equipment, gross	17,547	17,846
Buildings and leasehold improvements
Property, Plant and Equipment, Net
Property, plant, and equipment, gross	113,486	106,316
Furniture and equipment
Property, Plant and Equipment, Net
Property, plant, and equipment, gross	231,261	202,897
Property, plant and equipment in service, net
Property, Plant and Equipment, Net
Property, plant, and equipment, gross	362,294	327,059
Accumulated depreciation	(150,280)	(130,814)
Property, plant and equipment, net	212,014	196,245
Construction in progress
Property, Plant and Equipment, Net
Property, plant and equipment, net	$ 121,296	$ 117,173