XML 45 R44.htm IDEA: XBRL DOCUMENT v3.3.0.814
Intangible Assets (Intangible Assets Subject to Amortization) (Details) - USD ($)
$ in Millions
6 Months Ended
Sep. 30, 2015
Mar. 31, 2015
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Value $ 8,994 $ 8,988
Accumulated Amortization (3,839) (3,095)
Net Carrying Value 5,155 5,893
Customer Relationships [Member]    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Value 6,923 6,923
Accumulated Amortization (3,449) (2,791)
Net Carrying Value 3,474 4,132
Favorable spectrum leases [Member]    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Value 884 884
Accumulated Amortization (91) (71)
Net Carrying Value 793 813
Favorable tower leases [Member]    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Value 589 589
Accumulated Amortization (242) (189)
Net Carrying Value 347 400
Trademarks [Member]    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Value 520 520
Accumulated Amortization (35) (27)
Net Carrying Value 485 493
Other Finite Lived Intangible Assets [Member]    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Value 78 72
Accumulated Amortization (22) (17)
Net Carrying Value 56 55
Finite Lived Intangible Assets Excluding Customer Relationships [Member]    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Value 2,071 2,065
Accumulated Amortization (390) (304)
Net Carrying Value $ 1,681 $ 1,761
Minimum [Member] | Customer Relationships [Member]    
Finite-Lived Intangible Assets [Line Items]    
Finite-Lived Intangible Asset, Useful Life 4 years  
Minimum [Member] | Favorable tower leases [Member]    
Finite-Lived Intangible Assets [Line Items]    
Finite-Lived Intangible Asset, Useful Life 3 years  
Minimum [Member] | Other Finite Lived Intangible Assets [Member]    
Finite-Lived Intangible Assets [Line Items]    
Finite-Lived Intangible Asset, Useful Life 4 years  
Maximum [Member] | Customer Relationships [Member]    
Finite-Lived Intangible Assets [Line Items]    
Finite-Lived Intangible Asset, Useful Life 8 years  
Maximum [Member] | Favorable spectrum leases [Member]    
Finite-Lived Intangible Assets [Line Items]    
Finite-Lived Intangible Asset, Useful Life 23 years  
Maximum [Member] | Favorable tower leases [Member]    
Finite-Lived Intangible Assets [Line Items]    
Finite-Lived Intangible Asset, Useful Life 7 years  
Maximum [Member] | Trademarks [Member]    
Finite-Lived Intangible Assets [Line Items]    
Finite-Lived Intangible Asset, Useful Life 34 years  
Maximum [Member] | Other Finite Lived Intangible Assets [Member]    
Finite-Lived Intangible Assets [Line Items]    
Finite-Lived Intangible Asset, Useful Life 10 years