Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	1 Months Ended	6 Months Ended		0 Months Ended
	Jun. 19, 2013	Jun. 30, 2013	Jun. 30, 2012	Jul. 11, 2013 Dividend Paid [Member] Common Stockholders [Member]	Jul. 11, 2013 Dividend Paid [Member] Common Unitholders [Member]
Schedule Of Significant Accounting Policies [Line Items]
Common units issued		13,059,365
Percentage of Operating Partnership held		59.50%
Cash dividend declared, per share	$ 0.08
Cash dividend declared, payable date	Jul. 11, 2013
Cash dividend declared, record date	Jul. 01, 2013
Dividends paid		$ 12,927,000	$ 8,629,000	$ 1,500,000	$ 1,100,000
Dividend payable		$ 2,600,000