Summary of Significant Accounting Policies - Property, Plant and Equipment (Narrative) (Details)	12 Months Ended
	Dec. 31, 2018
Land Improvements
Property, Plant and Equipment
Estimated useful lives	15 years
Minimum | Building and Improvements
Property, Plant and Equipment
Estimated useful lives	10 years
Minimum | Machinery and Equipment
Property, Plant and Equipment
Estimated useful lives	3 years
Maximum | Building and Improvements
Property, Plant and Equipment
Estimated useful lives	39 years
Maximum | Machinery and Equipment
Property, Plant and Equipment
Estimated useful lives	20 years