Summary of Significant Accounting Policies - Summary of Useful Lives of Assets (Detail)	12 Months Ended
	Dec. 31, 2018
Real Estate Properties [Line Items]
Lease intangibles	Over lease term
Building [Member] | Minimum [Member]
Real Estate Properties [Line Items]
Estimated useful life of asset	30 years
Building [Member] | Maximum [Member]
Real Estate Properties [Line Items]
Estimated useful life of asset	40 years
Building and Land Improvements [Member]
Real Estate Properties [Line Items]
Estimated useful life of asset	10 years
Furniture, Fixtures and Equipment [Member] | Minimum [Member]
Real Estate Properties [Line Items]
Estimated useful life of asset	1 year
Furniture, Fixtures and Equipment [Member] | Maximum [Member]
Real Estate Properties [Line Items]
Estimated useful life of asset	7 years