Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended	12 Months Ended
	Feb. 29, 2012	Dec. 31, 2012 business_segments Casinos States Country	Dec. 31, 2011	Dec. 31, 2010
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of casinos operated or managed		52
Number of states in U.S where company operates		13
Number of countries operates		7
Number of land based casinos operated or managed		33
Number of riverboat or dockside casinos operated or managed		11
Number of casino combined with racetrack one		1
Number of casino combined with racetrack two		1
Number of casino combined with racetrack three		1
Reportable Segments		1
Common stock, stock split	1.742
Casino Reinvestment Development Authority Investment Obligations [Abstract]
Assessment of licenses		1.25%
Investment alternative tax		2.50%
Revenue Recognition [Abstract]
Cost of Promotional Allowances, Total Food and Beverage Expense		$ 477.1	$ 469.4	$ 475.6
Cost of Promotional Allowances, Room Expense		186.7	188.1	187.6
Cost of Promotional Allowances, Property general, admin and other		49.7	59.0	59.2
Cost of Promotional Allowances		713.5	716.5	722.4
Advertising Expense [Abstract]
Advertising expense		$ 194.2	$ 190.1	$ 195.5
Indian Land [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of casinos operated or managed		3
Cleveland, Ohio [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of casinos operated or managed		1
Canada [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of casinos operated or managed		1
Uruguay [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of land based casinos operated or managed		1
England [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of land based casinos operated or managed		9
Scotland [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of land based casinos operated or managed		1
Egypt [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of land based casinos operated or managed		2
South Africa [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of land based casinos operated or managed		1
Land improvements [Member]
Proprty and Equipment [Abstract]
Useful life of asset		12 years
Buildings [Member] | Minimum [Member]
Proprty and Equipment [Abstract]
Useful life of asset		30 years
Buildings [Member] | Maximum [Member]
Proprty and Equipment [Abstract]
Useful life of asset		40 years
Leasehold improvements [Member] | Minimum [Member]
Proprty and Equipment [Abstract]
Useful life of asset		5 years
Leasehold improvements [Member] | Maximum [Member]
Proprty and Equipment [Abstract]
Useful life of asset		15 years
Riverboats and barges [Member]
Proprty and Equipment [Abstract]
Useful life of asset		30 years
Furniture, fixtures, and equipment [Member] | Minimum [Member]
Proprty and Equipment [Abstract]
Useful life of asset		2 years 6 months
Furniture, fixtures, and equipment [Member] | Maximum [Member]
Proprty and Equipment [Abstract]
Useful life of asset		20 years