Schedule of Summarized Real Estate Secured Debt (Detail) - USD ($)			3 Months Ended
		Jul. 28, 2016	Mar. 31, 2017		Dec. 31, 2016
Debt Instrument [Line Items]
Debt Instrument Carrying Amount			$ 390,361,353
Debt issuance costs, net			(1,768,155)		$ (1,550,410)
Total			389,977,293		320,820,740
Amended KeyBank Credit Facility
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	[1]		$ 98,300,000		12,300,000
Debt Instrument, Interest Rate	[1]		3.03%
Debt Instrument Maturity Date	[1]		Dec. 22, 2018
Amended KeyBank Property Loan
Debt Instrument [Line Items]
Debt Instrument, Interest Rate	[2]		3.03%
Burlington I Variable Rate
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	[3]		$ 2,262,483		2,242,880
Debt Instrument, Interest Rate	[3]		4.93%
Debt Instrument Maturity Date	[3]		Oct. 15, 2018
Oakville I Variable Rate
Debt Instrument [Line Items]
Debt Instrument, Interest Rate	[3]		4.45%
Debt Instrument Maturity Date	[3]		Dec. 31, 2017
Burlington II and Oakville II Variable Rate
Debt Instrument [Line Items]
Debt Instrument, Interest Rate	[3]		3.40%
Debt Instrument Maturity Date	[3]		Feb. 28, 2021
Fixed Rate Secured Debt
Debt Instrument [Line Items]
Premium on secured debt, net			$ 1,962,760		2,069,847
Debt issuance costs, net			(2,346,820)		(2,605,542)
Total			389,977,293		310,820,740
Fixed Rate Secured Debt | Amended KeyBank Property Loan
Debt Instrument [Line Items]
Debt Instrument Carrying Amount, short term debt	[2]		$ 47,068,964		92,753,550
Debt Instrument Maturity Date	[2]		May 01, 2017
Fixed Rate Secured Debt | Raleigh Myrtle Beach Promissory Note
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	[4]		$ 12,215,266		12,263,391
Debt Instrument, Interest Rate	[4]		5.73%
Debt Instrument Maturity Date	[4]		Sep. 01, 2023
Fixed Rate Secured Debt | Milton Fixed Rate
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	[3]		$ 4,983,574		4,956,483
Debt Instrument, Interest Rate	[3]		5.81%
Debt Instrument Maturity Date	[3]		Oct. 15, 2018
Fixed Rate Secured Debt | Burlington I Fixed Rate
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	[3]		$ 4,891,092		4,870,817
Debt Instrument Maturity Date	[3]		Oct. 15, 2018
Debt Instrument Fixed Rate	[3]		5.98%
Fixed Rate Secured Debt | Oakville I Variable Rate
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	[3]		$ 7,552,374		7,486,937
Fixed Rate Secured Debt | Burlington II and Oakville II Variable Rate
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	[3]		12,276,273		12,232,378
Fixed Rate Secured Debt | Oakland and Concord Loan
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	[5]		$ 20,000,000		20,000,000
Debt Instrument, Interest Rate	[5]		3.95%
Debt Instrument Maturity Date	[5]		Apr. 10, 2023
Fixed Rate Secured Debt | KeyBank CMBS Loan
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	[6]		$ 95,000,000		95,000,000
Debt Instrument Maturity Date		Aug. 01, 2026	Aug. 01, 2026	[6]
Debt Instrument Fixed Rate		3.89%	3.89%	[6]
Fixed Rate Secured Debt | Midland North Carolina CMBS Loan
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	[7]		$ 47,249,999		47,249,999
Debt Instrument, Interest Rate	[7]		5.31%
Debt Instrument Maturity Date	[7]		Aug. 01, 2024
Fixed Rate Secured Debt | Dufferin Loan [Member]
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	[8]		$ 10,826,886		0
Debt Instrument, Interest Rate	[8]		3.21%
Debt Instrument Maturity Date	[8]		May 31, 2019
Fixed Rate Secured Debt | Mavis Loan [Member]
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	[8]		$ 9,126,183		0
Debt Instrument, Interest Rate	[8]		3.21%
Debt Instrument Maturity Date	[8]		May 31, 2019
Fixed Rate Secured Debt | Brewster Loan [Member]
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	[8]		$ 5,964,840		0
Debt Instrument Maturity Date	[8]		May 31, 2019
Debt Instrument Fixed Rate	[8]		3.21%
Fixed Rate Secured Debt | Granite Loan [Member]
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	[9]		$ 6,687,962		0
Debt Instrument, Interest Rate	[9]		5.45%
Debt Instrument Maturity Date	[9]		Jun. 15, 2018
Fixed Rate Secured Debt | Centennial Loan [Member]
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	[9]		$ 5,955,457		0
Debt Instrument, Interest Rate	[9]		5.70%
Debt Instrument Maturity Date	[9]		Jun. 15, 2018
Unsecured Debt [Member] | Amended KeyBank Subordinate Loan
Debt Instrument [Line Items]
Debt Instrument Carrying Amount, short term debt	[10]		$ 0		$ 10,000,000
Unsecured Debt [Member] | KeyBank Property Loan | Amended KeyBank Subordinate Loan
Debt Instrument [Line Items]
Debt Instrument, Interest Rate	[10]		6.25%
Debt Instrument Maturity Date	[10]		Mar. 31, 2017

[1] As of March 31, 2017, this facility encumbers 21 properties (Xenia, Sidney, Troy, Greenville, Washington Court House, Richmond, Connersville, Vallejo, Port St. Lucie I, Sacramento, Sonoma, Las Vegas I, Las Vegas II, Las Vegas III, Baltimore, Aurora II, Plantation, Wellington, Naples, Port St. Lucie II, and Doral).

[2] As of March 31, 2017, this loan encumbers five properties (Pompano Beach, Lake Worth, Jupiter, Royal Palm Beach, and Delray).

[3] Canadian Dollar denominated loans shown above in USD based on the foreign exchange rate in effect as of March 31, 2017. Variable rate loans are based on Canadian Prime, or the Canadian Dealer Offered Rate ("CDOR").

[4] Fixed rate debt with principal and interest payments due monthly. This promissory note is encumbered by five properties, Morrisville, Cary, Raleigh, Myrtle Beach I, and Myrtle Beach II.

[5] This loan was assumed during the acquisition of the Oakland and Concord properties, along with an interest rate swap with USAmeriBank that fixes the interest rate at 3.95%.

[6] This loan encumbers 29 properties (Whittier, La Verne, Santa Ana, Upland, La Habra, Monterey Park, Huntington Beach, Chico, Lancaster I, Riverside, Fairfield, Lompoc, Santa Rosa, Federal Heights, Aurora, Littleton, Bloomingdale, Crestwood, Forestville, Warren I, Sterling Heights, Troy, Warren II, Beverly, Everett, Foley, Tampa, Boynton Beach, and Lancaster II). The separate assets and credit of these encumbered properties are not available to pay our other debts.

[7] This loan encumbers 11 self storage properties (Asheville I, Arden, Asheville II, Hendersonville I, Asheville III, Asheville IV, Asheville V, Asheville VI, Asheville VII, Asheville VIII, and Hendersonville II) with monthly interest only payments until September 2019, at which time both interest and principal payments will be due monthly.

[8] Canadian Dollar denominated loans shown above in USD based on the foreign exchange rate in effect as of March 31, 2017. These loans were assumed during the Toronto Merger, along with an interest rate swap with the Bank of Montreal that fixes the interest rate at 3.21%.

[9] Canadian Dollar denominated loans shown above in USD based on the foreign exchange rate in effect as of March 31, 2017. The Granite and Centennial loans were assumed during the Toronto Merger with variable interest rates of 5.45% and 5.70%, respectively, as of March 31, 2017.

[10] The Amended KeyBank Subordinate Loan was repaid in full on March 8, 2017.