Segment Information (Long-Lived Assets By Geographic Area) (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2015
Mar. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]    
Long-lived assets $ 2,283 $ 2,410
North America [Member]    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Long-lived assets 1,809 1,940
International [Member]    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Long-lived assets $ 474 $ 470