Summary of Significant Accounting Policies (Property and Equipment) (Details)	12 Months Ended
	Dec. 31, 2018
Buildings and improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	7 years
Buildings and improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	40 years
Vehicles | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Vehicles | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	12 years
Landfill equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Landfill equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	7 years
Other equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Other equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	20 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years