NET INCOME PER SHARE - Calculations of Basic and Diluted Net Income Per Share, Including a Reconciliation of Numerators and Denominators (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Numerator:
Net income available to Extended Stay America, Inc. common shareholders - basic	$ 53,497	$ 65,056	$ 75,431	$ 79,908
Income attributable to noncontrolling interests assuming conversion	(7)	(1)	(12)	(26)
Net income available to common shareholders - diluted	$ 53,490	$ 65,055	$ 75,419	$ 79,882
Denominator:
Weighted-average number of Extended Stay America, Inc. common shares outstanding - basic (shares)	188,450	189,626	188,399	190,197
Dilutive securities (shares)	363	557	296	512
Weighted-average number of common shares outstanding - diluted (shares)	188,813	190,183	188,695	190,709
Net income per common share - basic (dollars per share)	$ 0.28	$ 0.34	$ 0.40	$ 0.42
Net income per common share - diluted (dollars per share)	$ 0.28	$ 0.34	$ 0.40	$ 0.42