Net Revenue and Net Income from Property Discontinued Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net revenue from discontinued operations									$ 6,734	$ 10,133	$ 11,203
Results from discontinued operations
Income from discontinued operations									932	1,672	552
Gain on sale of real estate from discontinued operations									36,720	3,981
Total income from discontinued operations	$ 36,999	$ 317	$ 228	$ 108	$ 95	$ 4,677	$ 627	$ 254	$ 37,652	$ 5,653	$ 552