XML 57 R38.htm IDEA: XBRL DOCUMENT

Summary of Acquisitions (Parenthetical) (Detail) $ in Thousands		12 Months Ended
	Sep. 03, 2017 USD ($) Property	Dec. 31, 2018 USD ($) Property	Dec. 31, 2017 USD ($) Property
Business Acquisition [Line Items]
Number of units in real estate properties acquired \| Property		2,379	2,340
Purchase Price		$ 272,948	$ 243,585
Defeasance costs related to properties acquired	$ 3,624
Acquisition of Nine-Property Portfolio First Phase Acquisition (HPI Portfolio)
Business Acquisition [Line Items]
Number of units in real estate properties acquired \| Property	2,352
Purchase Price	$ 228,144