Description of Business (Details) $ / shares in Units, $ in Millions			3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 26, 2019 USD ($)	Jun. 07, 2019 USD ($)	Sep. 30, 2019 USD ($) casino	Sep. 30, 2019 USD ($) casino	Jun. 30, 2020 USD ($) $ / shares shares
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of casinos operated or managed | casino			54	54
Payments for capital improvements			$ 10,918.0	$ 10,918.0
Capital Investment
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payments for capital improvements		$ 325.0
Up-front payments to the City
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payments for capital improvements		25.0
Additional one time payments to the city
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payments for capital improvements		40.0
Gaming Control Board Health research annual payment
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payments for capital improvements		3.4
Gaming Control Board annual license payment
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payments for capital improvements		3.0
Annual payments to the City
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payments for capital improvements		6.0
Minimum annual state gaming tax payments thru April 2022
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payments for capital improvements		60.0
Minimum annual state gaming tax payments after April 2022
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payments for capital improvements		$ 65.0
Eldorado Resorts, Inc. | Real Estate Purchase Agreements
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Aggregate consideration	$ 1,800.0
Increase in annual rent payment	99.0
Proceeds	$ 1,400.0
Due diligence period	90 days
Operating contract extension period		30 years
Forecast | Eldorado Resorts, Inc. | Caesars Entertainment, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Shares of Caesars common stock (in shares) | shares					682,161,838
Disposal group proposed merger post merger ownership percentage					49.00%
Merger agreement termination fee paid by caesars					$ 154.9
Reimbursable expenses maximum					50.0
Merger agreement termination fee					$ 836.8
Forecast | Eldorado Resorts, Inc. | Caesars Entertainment, Inc. | Cash per share
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Disposal group proposed merger agreement stock conversion price cash per share | $ / shares					$ 8.40
Forecast | Eldorado Resorts, Inc. | Caesars Entertainment, Inc. | Additional potential cash per share
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Disposal group proposed merger agreement stock conversion price cash per share | $ / shares					$ 0.003333
Forecast | Eldorado Resorts, Inc. | Caesars Entertainment, Inc. | Acquiror stock per share
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Disposal group proposed merger agreement stock conversion price					0.0899
Trading period					10 days
Forecast | Eldorado Resorts, Inc. | Caesars Entertainment, Inc. | Shares Held In Escrow
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Shares of Caesars common stock (in shares) | shares					8,271,660
Forecast | Eldorado Resorts, Inc. | Caesars Entertainment, Inc. | Common Stock
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Shares of Caesars common stock (in shares) | shares					76,000,000
Forecast | Caesars Entertainment, Inc. | Caesars Entertainment, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Merger agreement termination fee paid by caesars					$ 418.4
United States
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of casinos operated or managed | casino			50	50
Geographic concentration risk | United States
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of casinos operated or managed | casino			14	14
Geographic concentration risk | United States | Las Vegas
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of casinos operated or managed | casino			9	9
Geographic concentration risk | International
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of casinos operated or managed | casino			5	5
Geographic concentration risk | Revenue benchmark | United States | Las Vegas
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Concentration risk, percentage			44.00%	45.00%