Stock-Based Compensation - Schedule of Option Activity (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018
Options
Fully vested and expected to vest as of December 31, 2018				345,790
Weighted Average Exercise Price
Fully vested and expected to vest as of December 31, 2018				$ 60.99
Weighted Average Remaining Contractual Term
Fully vested and expected to vest as of December 31, 2018	1 year 2 months 30 days
Aggregate Intrinsic Value
Fully vested and expected to vest as of December 31, 2018				$ 14,796,122
Stock Option Exercises from the Plans [Abstract]
Cash received from the exercise of stock options	$ 21,971,000	$ 62,209,000	$ 3,487,000
Wynn Resorts Limited 2014 Omnibus Incentive Plan
Options
Outstanding as of January 1, 2018	345,790	644,460		345,790
Granted	0
Exercised	(261,470)
Forfeited or expired	(37,200)
Outstanding as of December 31, 2018	345,790	644,460
Exercisable as of December 31, 2018				285,790
Weighted Average Exercise Price
Outstanding as of January 1, 2018	$ 73.93
Granted	0.00
Exercised	77.07
Forfeited or expired	172.07
Outstanding as of December 31, 2018	$ 60.99	$ 73.93
Exercisable as of December 31, 2018				$ 63.91
Weighted Average Remaining Contractual Term
Outstanding as of December 31, 2018	1 year 2 months 30 days
Exercisable as of December 31, 2018	1 year 5 months 9 days
Aggregate Intrinsic Value
Outstanding as of December 31, 2018				$ 14,796,122
Exercisable as of December 31, 2018				$ 11,688,722
Stock Option Exercises from the Plans [Abstract]
Weighted average grant date fair value	$ 0.00	$ 0.00	$ 34.90
Intrinsic value of stock options exercised	$ 22,387,000	$ 29,716,000	$ 3,657,000
Cash received from the exercise of stock options	$ 20,148,000	$ 61,506,000	$ 3,487,000
Share Option Plan
Options
Outstanding as of January 1, 2018	10,558,400	7,006,000		10,558,400
Granted	4,494,000
Exercised	(941,600)
Outstanding as of December 31, 2018	10,558,400	7,006,000
Fully vested and expected to vest as of December 31, 2018				10,558,400
Exercisable as of December 31, 2018				3,302,800
Weighted Average Exercise Price
Outstanding as of January 1, 2018	$ 2.32
Granted	2.65
Exercised	1.94
Outstanding as of December 31, 2018	$ 2.49	$ 2.32
Fully vested and expected to vest as of December 31, 2018				$ 2.49
Exercisable as of December 31, 2018				$ 2.72
Weighted Average Remaining Contractual Term
Outstanding as of December 31, 2018	7 years 9 months 18 days
Fully vested and expected to vest as of December 31, 2018	7 years 9 months 18 days
Exercisable as of December 31, 2018	5 years 2 months 12 days
Aggregate Intrinsic Value
Outstanding as of December 31, 2018				$ 1,403,732
Fully vested and expected to vest as of December 31, 2018				1,403,732
Exercisable as of December 31, 2018				$ 484,717
Stock Option Exercises from the Plans [Abstract]
Weighted average grant date fair value	$ 0.57	$ 0.56	$ 0.31
Intrinsic value of stock options exercised	$ 1,715,000	$ 369,000	$ 0
Cash received from the exercise of stock options	$ 1,823,000	$ 703,000	$ 0