Summary Of Mortgages Payable (Detail) (USD $)	9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011
Debt Instrument [Line Items]
Mortgages payable	$ 4,295,000	$ 4,423,000
6.76% Mortgage Note Due September 2013 [Member]
Debt Instrument [Line Items]
Mortgages payable	904,000	925,000
Term note stated interest rate	6.76%
Mortgage note due date	Sep. 11, 2013
Self-storage facilities	1
Aggregate net book value of property pledged for mortgage note	1,900,000
Effective interest rate	6.89%
6.35% Mortgage Note Due March 2014 [Member]
Debt Instrument [Line Items]
Mortgages payable	991,000	1,014,000
Term note stated interest rate	6.35%
Mortgage note due date	Mar. 11, 2014
Self-storage facilities	1
Aggregate net book value of property pledged for mortgage note	3,500,000
Effective interest rate	6.48%
5.99% Mortgage Note Due May 2026 [Member]
Debt Instrument [Line Items]
Mortgages payable	2,400,000	2,484,000
Term note stated interest rate	5.99%
Mortgage note due date	May 01, 2026
Self-storage facilities	1
Aggregate net book value of property pledged for mortgage note	$ 4,200,000
Effective interest rate	6.19%
Line Of Credit - Variable Rate LIBOR + 2.0% (2.22% At September30, 2012) [Member]
Debt Instrument [Line Items]
Basis spread over LIBOR	2.00%
Interest rate at end of period	2.22%
Term Note - Variable Rate LIBOR+1.50% (2.21% At September30, 2012) [Member]
Debt Instrument [Line Items]
Basis spread over LIBOR	1.50%
Interest rate at end of period	2.21%
Term Note - Fixed Rate 6.26% [Member]
Debt Instrument [Line Items]
Interest rate at end of period	6.26%
Term Note - Fixed Rate 6.38% [Member]
Debt Instrument [Line Items]
Interest rate at end of period	6.38%
Term Note - Variable Rate LIBOR+2.0% (2.23% at September 20, 2012) One [Member]
Debt Instrument [Line Items]
Basis spread over LIBOR	2.00%
Interest rate at end of period	2.23%
Term Note - Variable Rate LIBOR+2.0% (2.22% at September 20, 2012) One [Member]
Debt Instrument [Line Items]
Basis spread over LIBOR	2.00%
Interest rate at end of period	2.22%
Term Note - Fixed Rate 5.54% [Member]
Debt Instrument [Line Items]
Term note stated interest rate	5.54%