Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Significant Accounting Policies [Line Items]
Earned asset management fees	$ 1,223	$ 1,228	$ 2,439	$ 2,513
Eliminated management fee income	$ 863	$ 906	$ 1,746	$ 1,876
Buildings and improvements | Maximum
Significant Accounting Policies [Line Items]
Property, useful lives			40 years
Buildings and improvements | Minimum
Significant Accounting Policies [Line Items]
Property, useful lives			30 years
Furniture, fixtures, and equipment | Maximum
Significant Accounting Policies [Line Items]
Property, useful lives			10 years
Furniture, fixtures, and equipment | Minimum
Significant Accounting Policies [Line Items]
Property, useful lives			5 years