Investment in Joint Ventures - Additional Information (Detail) (USD $)	3 Months Ended				12 Months Ended				12 Months Ended				3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Sovran HHF and Sovran HHF II [Member]	Mar. 31, 2013 Sovran HHF and Sovran HHF II [Member]	Dec. 31, 2013 Sovran HHF Storage Holdings LLC [Member]	Dec. 31, 2012 Sovran HHF Storage Holdings LLC [Member]	Dec. 31, 2008 Sovran HHF Storage Holdings LLC [Member] Property	Mar. 31, 2014 Sovran HHF Storage Holdings LLC [Member]	Dec. 31, 2012 Sovran HHF Storage Holdings II LLC [Member] Property	Dec. 31, 2011 Sovran HHF Storage Holdings II LLC [Member] Property	Mar. 31, 2014 Sovran HHF Storage Holdings II LLC [Member]	Dec. 31, 2013 Sovran HHF Storage Holdings II LLC [Member]	Mar. 31, 2014 Iskalo Office Holdings, LLC [Member]	Mar. 31, 2013 Iskalo Office Holdings, LLC [Member]	Dec. 31, 2013 Iskalo Office Holdings, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest								20.00%			15.00%		49.00%
Investment at carrying value					$ 17,400,000			$ 17,300,000			$ 12,900,000	$ 12,800,000	$ (500,000)		$ (500,000)
Payment for property acquisition	95,350,000						171,500,000		29,000,000	166,100,000
Number of properties owned and managed under twenty-percent stake joint venture							25
Contribution of company to joint venture as share in capital						1,200,000	18,600,000		2,400,000	12,800,000
Receipt of return of capital distribution					3,400,000
Excess of investment over net asset due to capitalization of acquisition related costs								1,700,000
Number of properties owned and managed under fifteen-percent stake joint venture									10	20
Management and call center fee as a percentage of revenues			7.00%
Management and call center fee earned			900,000	800,000
Company's share in income (loss) of joint venture	458,000	386,000	400,000	400,000									32,000	21,000
Rent paid during the period													$ 300,000	$ 200,000