Variable Interest Entities (VIEs) - Schedule of Operating Results Relating to Entities (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Variable Interest Entity [Line Items]
Revenue	$ 2,712,559	$ 2,275,076	$ 7,155,568	$ 6,262,724
Operating, administrative and other expenses	626,905	601,026	1,768,838	1,695,623
Gain on disposition of real estate	3,154	7,235	10,140	37,102
Net income attributable to non-controlling interests	$ 868	$ 2,593	$ 9,193	27,607
Variable Interest Entities [Member]
Variable Interest Entity [Line Items]
Revenue				3,561
Operating, administrative and other expenses				2,588
Gain on disposition of real estate				23,028
Net income attributable to non-controlling interests				$ 21,724