Summary of Significant Accounting Policies - Summary of Estimated Useful Lives of Real property Assets (Detail)	12 Months Ended
	Dec. 31, 2018
Land [Member]
Property, Plant and Equipment [Line Items]
Standard Depreciable Life, Description	Not Depreciated
Buildings [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Standard depreciable life	35 years
Buildings [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Standard depreciable life	40 years
Site Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Standard depreciable life	7 years
Site Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Standard depreciable life	10 years