Impairment of Long-Lived Assets - Additional Information (Detail)		3 Months Ended				9 Months Ended
	Apr. 17, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($) Property	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)
Property Plant And Equipment [Abstract]
Impairment charges		$ 0		$ 510,000	$ 421,040	$ 510,041	$ 421,040
Number of income properties held for sales | Property				2
Gain (loss) on sale of property	$ (497,000)		$ 13,000	$ (277,000)			(228,000)
Estimated closing costs				$ 233,000			$ 193,000