Disposition of Real Estate and Discontinued Operations - Operating Results Related to Assets Sold (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Discontinued Operations And Disposal Groups [Abstract]
Revenues		$ 10,785		$ 36,367
Expenses
Operating expenses		2,773		9,784
Impairment charges	$ 0	365	$ 0	8,877
Interest, net		2,670		9,176
Depreciation and amortization		4,513		14,891
Total expenses, discontinued operations		10,321		42,728
Income (loss) from discontinued operations		464		(6,361)
Gain on disposition of real estate, net of tax		57,105		74,287
Income from discontinued operations	$ 0	$ 57,569	$ 0	$ 67,926