XML 50 R34.htm IDEA: XBRL DOCUMENT v3.7.0.1
Summary of Significant Accounting Policies - Estimated Useful Lives of Real Estate Investments (Detail)
3 Months Ended
Mar. 31, 2017
Minimum | Buildings and building improvements  
Property Subject to or Available for Operating Lease [Line Items]  
Estimated useful lives 20 years
Minimum | Land improvements  
Property Subject to or Available for Operating Lease [Line Items]  
Estimated useful lives 10 years
Minimum | Fixtures and integral equipment  
Property Subject to or Available for Operating Lease [Line Items]  
Estimated useful lives 3 years
Maximum | Buildings and building improvements  
Property Subject to or Available for Operating Lease [Line Items]  
Estimated useful lives 40 years
Maximum | Land improvements  
Property Subject to or Available for Operating Lease [Line Items]  
Estimated useful lives 20 years
Maximum | Fixtures and integral equipment  
Property Subject to or Available for Operating Lease [Line Items]  
Estimated useful lives 20 years