v2.4.0.6
Consolidated Statements of Changes in Equity (Parenthetical) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Proceeds from issuance of offering costs $ 4.9 $ 9.4 $ 3.1
Class A [Member] | Common Stock and Paid-in Capital [Member]
     
Proceeds from issuance of offering costs $ 4.9 $ 9.4 $ 3.1