v2.4.0.8
Commitments and Contingencies (Loss Contingency) (Details) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Sep. 30, 2013
action
Sep. 30, 2013
Property Tax Assessment
Dec. 31, 2009
State of Nevada Department of Taxation
Sales and Use Tax Deficiency
Dec. 31, 2009
State of New Jersey
Real Estate Taxes [Member]
Dec. 31, 2010
Subsidiary, Borgata
Property Tax Assessment
Dec. 31, 2009
Subsidiary, Borgata
Property Tax Assessment
Loss Contingencies [Line Items]            
Number of legal actions brought against company to date 2          
Amount of assessment by taxing authority     $ 12.3 $ 2,300.0    
Amount of interest assessed by taxing authority     7.5      
Increase in assessed property value, percentage   46.00%        
Range of possible additional property tax obligation, minimum   5.4        
Range of possible additional tax obligation, maximum   14.7     870.0 880.0
Accrual for potential property tax obligation   $ 14.7