Stock-Based Compensation - Schedule of Option Activity (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019
Options
Fully vested and expected to vest as of December 31, 2019				23,700
Weighted Average Exercise Price
Fully vested and expected to vest as of December 31, 2019				$ 80.42
Weighted Average Remaining Contractual Term
Fully vested and expected to vest as of December 31, 2019	6 years 1 month 28 days
Aggregate Intrinsic Value
Fully vested and expected to vest as of December 31, 2019				$ 1,385,194
Stock Option Exercises from the Plans [Abstract]
Cash received from the exercise of stock options	$ 14,696,000	$ 21,971,000	$ 62,209,000
Wynn Resorts Limited 2014 Omnibus Incentive Plan
Options
Outstanding as of January 1, 2019	23,700	345,790		23,700
Granted	0
Exercised	(293,690)
Forfeited or expired	(28,400)
Outstanding as of December 31, 2019	23,700	345,790
Exercisable as of December 31, 2019				23,700
Weighted Average Exercise Price
Outstanding as of January 1, 2019	$ 60.99
Granted	0
Exercised	50.04
Forfeited or expired	158.09
Outstanding as of December 31, 2019	$ 80.42	$ 60.99
Exercisable as of December 31, 2019				$ 80.42
Weighted Average Remaining Contractual Term
Outstanding as of December 31, 2019	6 years 1 month 28 days
Exercisable as of December 31, 2019	6 years 1 month 28 days
Aggregate Intrinsic Value
Outstanding as of December 31, 2019				$ 1,385,194
Exercisable as of December 31, 2019				$ 1,385,194
Stock Option Exercises from the Plans [Abstract]
Intrinsic value of stock options exercised	$ 24,731,000	$ 22,387,000	29,716,000
Cash received from the exercise of stock options	$ 14,696,000	$ 20,148,000	$ 61,506,000
Original Share Option Plan
Options
Outstanding as of January 1, 2019	11,013,400	10,558,400		11,013,400
Granted	455,000
Exercised	0
Outstanding as of December 31, 2019	11,013,400	10,558,400
Fully vested and expected to vest as of December 31, 2019				11,013,400
Exercisable as of December 31, 2019				5,212,000
Weighted Average Exercise Price
Outstanding as of January 1, 2019	$ 2.49
Granted	2.54
Exercised	0
Outstanding as of December 31, 2019	$ 2.51	$ 2.49
Fully vested and expected to vest as of December 31, 2019				$ 2.51
Exercisable as of December 31, 2019				$ 2.60
Weighted Average Remaining Contractual Term
Outstanding as of December 31, 2019	6 years 10 months 13 days
Fully vested and expected to vest as of December 31, 2019	6 years 10 months 13 days
Exercisable as of December 31, 2019	5 years 4 months 13 days
Aggregate Intrinsic Value
Outstanding as of December 31, 2019				$ 2,521,979
Fully vested and expected to vest as of December 31, 2019				2,521,979
Exercisable as of December 31, 2019				$ 1,398,941
Stock Option Exercises from the Plans [Abstract]
Weighted average grant date fair value	$ 0.55	$ 0.57	$ 0.56
Intrinsic value of stock options exercised	$ 0	$ 1,715,000	$ 369,000
Cash received from the exercise of stock options	$ 0	$ 1,823,000	$ 703,000