Fair Value Measurements Fair Value Measurements - Changes in Level 3 Fair Value Measurements (Details) - Liability [Member] - Estimate of Fair Value Measurement [Member] - Fair Value, Measurements, Recurring [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance as of beginning of period	$ 102	$ 112
Restructuring of CEOC and other	(1)	(9)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	(15)	(17)
Balance as of end of period	86	86
CEC Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance as of beginning of period	856	1,016
Restructuring of CEOC and other	(25)	(185)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	0	0
Balance as of end of period	$ 831	$ 831