Summary of Significant Accounting Policies (Property, Plant and Equipment Useful Lives) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Interest Costs Capitalized		$ 0.5	$ 0.1
Interest Cost Capitalized	no
Building and Improvements \| Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives	3 years
Building and Improvements \| Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives	40 years
Riverboats and Barges \| Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives	5 years
Riverboats and Barges \| Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives	40 years
Furniture and Equipment \| Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives	1 year
Furniture and Equipment \| Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives	10 years