v2.4.0.6
CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)
Dec. 31, 2011
Stockholders' Equity  
Preferred stock, par value (in dollars per share) $ 0.01
Preferred stock, shares authorized (in shares) 10,000,000
Preferred stock, shares outstanding (in shares) 0.0
Class P [Member]
  
Stockholders' Equity  
Common stock, par value (in dollars per share) $ 0.01
Common stock, shares authorized (in shares) 2,000,000,000
Common stock, shares issued (in shares) 170,921,140
Common stock, shares outstanding (in shares) 170,921,140
Class A [Member]
  
Stockholders' Equity  
Common stock, par value (in dollars per share) $ 0.01
Common stock, shares authorized (in shares) 707,000,000
Common stock, shares issued (in shares) 535,972,387
Common stock, shares outstanding (in shares) 535,972,387
Class B [Member]
  
Stockholders' Equity  
Common stock, par value (in dollars per share) $ 0.01
Common stock, shares authorized (in shares) 100,000,000
Common stock, shares issued (in shares) 94,132,596
Common stock, shares outstanding (in shares) 94,132,596
Class C [Member]
  
Stockholders' Equity  
Common stock, par value (in dollars per share) $ 0.01
Common stock, shares authorized (in shares) 2,462,927
Common stock, shares issued (in shares) 2,318,258
Common stock, shares outstanding (in shares) 2,318,258