Credit Facilities and Mortgage Notes Payable - Richmond Credit Facility - Additional Information (Detail) (Richmond Credit Facility [Member], USD $) In Millions, unless otherwise specified	12 Months Ended			1 Months Ended
	Dec. 31, 2013	Jan. 31, 2013	Dec. 31, 2012	Dec. 31, 2012 Minimum [Member]	Dec. 31, 2012 Maximum [Member]
Debt Instrument [Line Items]
Credit Facility maximum borrowing capacity		$ 100	$ 80
Increased borrowing capacity after considering accordion feature		$ 125
Credit facility interest rate description	Interest at variable rates ranging from LIBOR plus 4.0% to LIBOR plus 4.5%. The interest rate at December 31, 2013 was LIBOR plus 4.00%, or 4.16% per annum
Credit facility base for variable interest rate spread rate	4.00%			4.00%	4.50%
Credit facility base for variable interest rate spread rate	4.16%
Credit facility, maturity date	Dec. 18, 2015
Additional extension period credit facility	1 year