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								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Numerator:
Net Income (Loss) Available to Common Stockholders, Basic	$ (46,834)	$ 41,071	$ 53,497	$ 21,934	$ (38,946)	$ 71,902	$ 65,056	$ 14,852	$ 69,668	$ 112,864	$ 78,847
Income attributable to noncontrolling interests assuming conversion									(82)	(128)	(392)
Net income available to Extended Stay America, Inc. common shareholders - diluted									$ 69,586	$ 112,736	$ 78,455
Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract]
Weighted-average number of Extended Stay America, Inc. common shares outstanding - basic (in shares)									186,546	189,389	193,101
Dilutive securities (in shares)									276	432	569
Weighted-average number of common shares outstanding - diluted (in shares)									186,822	189,821	193,670
Net income per common share-basic (in dollars per share)	$ (0.26)	$ 0.22	$ 0.28	$ 0.12	$ (0.21)	$ 0.38	$ 0.34	$ 0.08	$ 0.37	$ 0.60	$ 0.41
Net income per common share-diluted (in dollars per share)	$ (0.26)	$ 0.22	$ 0.28	$ 0.12	$ (0.21)	$ 0.38	$ 0.34	$ 0.08	$ 0.37	$ 0.59	$ 0.41