Property, Plant, and Equipment, Net (Schedule of Property, Plant, and Equipment, Net) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Impairment of Long-Lived Assets Held-for-use	$ 2,072,000	$ 1,401,000	$ 4,310,000
Property, plant, and equipment, gross	780,950,000	737,205,000
Less accumulated depreciation	(489,354,000)	(455,811,000)
Property, plant, and equipment, net	291,596,000	281,394,000
Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	20,961,000	21,065,000
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	170,928,000	173,919,000
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	327,678,000	322,032,000
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	88,305,000	83,613,000
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	131,756,000	121,949,000
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 41,322,000	$ 14,627,000