Summary of Significant Accounting Policies - Land, Buildings, Vessels and Equipment (Details) (USD $)	12 Months Ended			3 Months Ended	12 Months Ended									3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Sep. 30, 2012 Base Stock	Dec. 31, 2012 Base Stock	Dec. 31, 2012 Minimum Land Improvements	Dec. 31, 2012 Minimum Buildings and Improvements	Dec. 31, 2012 Minimum Vessels	Dec. 31, 2012 Minimum Furniture, Fxtures and Equipment	Dec. 31, 2012 Maximum Land Improvements	Dec. 31, 2012 Maximum Buildings and Improvements	Dec. 31, 2012 Maximum Vessels	Dec. 31, 2012 Maximum Furniture, Fxtures and Equipment	Dec. 31, 2012 River Downs
Land, Buildings, Vessels and Equipment
Land not used in operations	$ 27,200,000	$ 30,300,000
Asset Reclassification				4,500,000
Depreciation and amortization	115,694,000	103,863,000	109,745,000		400,000
Depreciation expense	$ 115,500,000	$ 103,700,000	$ 109,600,000											$ 4,700,000
Estimated Useful Life						5 years	15 years	10 years	3 years	20 years	35 years	25 years	20 years