Intangible Lease Assets and Liabilities - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Intangible Assets And Liabilities [Line Items]
Total amortization expense	$ 1,100,000	$ 718,000
Income Properties Revenue [Member]
Intangible Assets And Liabilities [Line Items]
Amortization of lease liabilities in income properties	$ 1,200,000