Equity - Distributions of promoted interest to share holders (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2014
Class Of Stock [Line Items]
Distributions to holders of promoted interest	$ (6,650)	$ (2,000)
Dogwood Forest Of Acworth
Class Of Stock [Line Items]
Distributions to holders of promoted interest	(3,850)
Wellmore of Tega Cay
Class Of Stock [Line Items]
Distributions to holders of promoted interest	$ (2,800)
Harborchase of Villages Crossing
Class Of Stock [Line Items]
Distributions to holders of promoted interest		$ (2,000)