Significant Accounting Policies - Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2019
Land improvements
Estimated useful lives of property and equipment
Useful lives	15 years
Building and improvements | Minimum
Estimated useful lives of property and equipment
Useful lives	5 years
Building and improvements | Maximum
Estimated useful lives of property and equipment
Useful lives	31 years
Vessels | Minimum
Estimated useful lives of property and equipment
Useful lives	10 years
Vessels | Maximum
Estimated useful lives of property and equipment
Useful lives	35 years
Furniture, fixtures and equipment | Minimum
Estimated useful lives of property and equipment
Useful lives	3 years
Furniture, fixtures and equipment | Maximum
Estimated useful lives of property and equipment
Useful lives	31 years