Summary of Significant Accounting Policies - Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2019
Building and building improvements | Minimum
Property and Equipment [Line Items]
Property and Equipment, Useful Life	20 years
Building and building improvements | Maximum
Property and Equipment [Line Items]
Property and Equipment, Useful Life	40 years
Advertising structures | Minimum
Property and Equipment [Line Items]
Property and Equipment, Useful Life	5 years
Advertising structures | Maximum
Property and Equipment [Line Items]
Property and Equipment, Useful Life	20 years
Furniture, equipment and other | Minimum
Property and Equipment [Line Items]
Property and Equipment, Useful Life	3 years
Furniture, equipment and other | Maximum
Property and Equipment [Line Items]
Property and Equipment, Useful Life	10 years