Property, Plant and Equipment (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Property, Plant and Equipment [Line Items]
Increase (Decrease) in Accounts Payable			$ 900	$ 2,100
Impairments	$ 85	$ 0	85	0
Leased devices [Member]
Property, Plant and Equipment [Line Items]
Increase (Decrease) in Accounts Payable			206	1
Increase (Decrease) in Inventories			$ 1,550	$ 70