Pension Benefits Pension Benefits Tables (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Defined Benefit Plan Disclosure [Line Items]
Net periodic pension expense	$ 12	$ 10	$ 23	$ 21
United States Pension Plan of US Entity, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	0	1	1	2
Interest cost on projected benefit obligation	4	5	9	10
Expected return on assets	(5)	(5)	(11)	(10)
Amortization of unrecognized actuarial loss, prior service costs and net transitional obligation	6	7	10	16
Net periodic pension expense	5	8	9	18
Foreign Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	5	1	9	2
Interest cost on projected benefit obligation	9	2	18	3
Expected return on assets	(8)	(2)	(15)	(4)
Amortization of unrecognized actuarial loss, prior service costs and net transitional obligation	1	1	2	2
Net periodic pension expense	$ 7	$ 2	$ 14	$ 3