Summary of Significant Accounting Policies - Summary of Estimated Useful Lives (Detail)	9 Months Ended
	Sep. 30, 2015
Tenant Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	Shorter of lease term or expected useful life
Integral Equipment, Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Minimum [Member] | Buildings [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	25 years
Minimum [Member] | Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	10 years
Maximum [Member] | Buildings [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	40 years
Maximum [Member] | Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	25 years