Goodwill And Acquisition-Related Intangibles, Net (Tables)
 12 Months Ended
Mar. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]  
Schedule Of Changes In The Carrying Amount Of Goodwill
The changes in the carrying amount of goodwill for the fiscal year ended March 31, 2015 are as follows (in millions):
 
As of
March 31, 2014
 
Activity
 
Effects of Foreign Currency Translation
 
As of
March 31, 2015
Goodwill
$
2,091

 
$
—

 
$
(10
)
 
$
2,081

Accumulated impairment
(368
)
 
—

 
—

 
(368
)
Total
$
1,723

 
$
—

 
$
(10
)
 
$
1,713


The changes in the carrying amount of goodwill for the fiscal year ended March 31, 2014 are as follows (in millions):
 
As of
March 31, 2013
 
Activity
 
Effects of Foreign Currency Translation
 
As of
March 31, 2014
Goodwill
$
2,089

 
$
5

 
$
(3
)
 
$
2,091

Accumulated impairment
(368
)
 
—

 
—

 
(368
)
Total
$
1,721

 
$
5

 
$
(3
)
 
$
1,723
Schedule Of Acquisition-Related Intangibles
Acquisition-related intangibles, consisted of the following (in millions): 
 
As of March 31, 2015
 
As of March 31, 2014
 
Gross
Carrying
Amount
 
Accumulated
Amortization
 
Acquisition-
Related
Intangibles, Net
 
Gross
Carrying
Amount
 
Accumulated
Amortization
 
Acquisition-
Related
Intangibles, Net
Developed and core technology
$
531

 
$
(439
)
 
$
92

 
$
531

 
$
(385
)
 
$
146

Trade names and trademarks
130

 
(111
)
 
19

 
130

 
(105
)
 
25

Registered user base and other intangibles
87

 
(87
)
 
—

 
87

 
(87
)
 
—

Carrier contracts and related
85

 
(85
)
 
—

 
85

 
(79
)
 
6

Total
$
833

 
$
(722
)
 
$
111

 
$
833

 
$
(656
)
 
$
177
Schedule Of Amortization Of Intangible Assets
Amortization of intangibles for the fiscal years ended March 31, 2015, 2014 and 2013 are classified in the Consolidated Statement of Operations as follows (in millions): 
 
Year Ended March 31,
 
2015
 
2014
 
2013
Cost of product
$
16

 
$
33

 
$
55

Cost of service and other
36

 
27

 
38

Operating expenses
14

 
16

 
30

Total
$
66

 
$
76

 
$
123
Schedule Of Future Amortization Of Acquisition-Related Intangibles
As of March 31, 2015, future amortization of acquisition-related intangibles that will be recorded in the Consolidated Statement of Operations is estimated as follows (in millions): 
Fiscal Year Ending March 31,
 
2016
$
53

2017
32

2018
12

2019
8

2020
6

Thereafter
—

Total
$
111