v3.3.0.814
Number of Shares of Class A Common Shares Outstanding on an As-Converted Basis (Detail)
shares in Millions
Sep. 30, 2015
conversion_rate
shares
Mar. 19, 2015
conversion_rate
Sep. 30, 2014
shares
Class of Stock [Line Items]      
As-converted Class A Common Stock [1] 2,434    
Class A common stock      
Class of Stock [Line Items]      
Common stock, shares, outstanding 1,950   1,978
As-converted Class A Common Stock [1] 1,950    
Class B common stock      
Class of Stock [Line Items]      
Common stock, shares, outstanding 245   245
Common stock, conversion rate | conversion_rate [2] 1.6483 1.6483  
As-converted Class A Common Stock [1] 405    
Class C common stock      
Class of Stock [Line Items]      
Common stock, shares, outstanding 20   22
Common stock, conversion rate | conversion_rate 4.0 4.0  
As-converted Class A Common Stock [1] 79    
[1] Figures in the table may not recalculate exactly due to rounding. As-converted class A common stock is calculated based on unrounded numbers.
[2] The class B to class A common stock conversion rate is presented on a rounded basis. Conversion calculations for dividend payments are based on a conversion rate rounded to the tenth decimal.