Related Party Transactions and Interests in Consolidated Entities - Net Income Attributable to Non-Controlling Interests (Parenthetical) (Detail) (AAA Investments [Member])	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
AAA Investments [Member]
Related Party Transaction [Line Items]
Non-controlling interests ownership percentage in AAA	97.00%	97.00%	97.00%	98.00%