Combined Financial Statements for Limited Partnerships Recorded Under Equity Method of Accounting (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Assets
Land and property	$ 32,240	$ 32,025
Other assets	16,217	16,300
Total assets	1,422,458	1,427,193
Liabilities
Notes payable	7,589	8,436
Other liabilities	12,675	12,348
Total liabilities	1,282,965	1,294,566
Partners' equity
Total revenue	6,606	6,603	6,213
Total expenses	(6,905)	(7,518)	(7,053)
Net loss	(299)	(915)	(840)
Equity Method Investments
Assets
Cash	367	449
Land and property	50,361	52,003
Other assets	2,485	2,390
Total assets	53,213	54,842
Liabilities
Notes payable	43,764	45,310
Other liabilities	1,394	1,066
Total liabilities	45,158	46,376
Partners' equity
General partners	(3,649)	(3,521)
Limited partners	11,704	11,987
Total partners' equity	8,055	8,466
Total liabilities and partners' equity	$ 53,213	$ 54,842