Net Income (Loss) Per Class A Share - Transactions in Class A Shares and Impact on Company's and Holdings' Ownership Interests (Parenthetical) (Detail) (Class A Shares [Member]) In Millions, unless otherwise specified	1 Months Ended
	May 14, 2013
Class A Shares [Member]
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Shares issued for conversion	8.8