Investments in Unconsolidated Affiliates, Included in Real Estate Investments (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Investments in and Advances to Affiliates [Line Items]
Investments in unconsolidated affiliates	$ 2,222		$ 2,259
East San Marco L.L.C
Investments in and Advances to Affiliates [Line Items]
Ownership	50.00%
Investments in unconsolidated affiliates	2,222		2,165
Rivercrest, L.L.C
Investments in and Advances to Affiliates [Line Items]
Ownership	50.00%
Paseos, L.L.C
Investments in and Advances to Affiliates [Line Items]
Ownership	50.00%	[1]
Investments in unconsolidated affiliates			$ 94	[1]
ALP Liquidating Trust
Investments in and Advances to Affiliates [Line Items]
Ownership	26.00%

[1] Paseos, LLC was dissolved as of December 2012.