Acquisitions, Investments, Dispositions and Divestitures - Income from Discontinued Operations (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended							12 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net revenues								$ 212.0	$ 261.2	$ 265.4
Pre-tax (loss)/income from operations	3.0	105.9	(15.4)	(12.8)	4.0	4.1	(15.5)	(59.4)	59.2	49.9
(Loss)/income, net of income taxes								(109.5)	31.4	26.1
Harrahs St. Louis [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net revenues								208.4	257.7	262.4
Pre-tax (loss)/income from operations								62.2	75.3	65.7
(Loss)/income, net of income taxes								(1.7)	45.8	39.8
Macau [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net revenues								3.6	3.5	3.0
Pre-tax (loss)/income from operations								(121.6)	(16.1)	(15.8)
(Loss)/income, net of income taxes								$ (107.8)	$ (14.4)	$ (13.7)