Debt 5 (Details) (USD $)	12 Months Ended			1 Months Ended		2 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013	Jun. 30, 2013	Aug. 31, 2013	Dec. 01, 2014	Dec. 31, 2009
Debt Disclosure [Abstract]
Interest expense	$ 77,000,000	$ 75,000,000	$ 64,000,000
Debt Instruments
Debt issuance costs	0	5,000,000	0
Proceeds from issuance of Senior Notes	0	498,000,000	0
Senior Notes, Discount	4,000,000	5,000,000
Revolving Credit Facility
Debt Instruments
Maximum committed amount available under revolving credit facility	1,000,000,000
Maximum available credit increase under revolving credit facility	500,000,000
Borrowings outstanding	0	0
Debt issuance costs				1,000,000
Borrowing activity	0	0	0
Revolving credit facility, Covenant description	The revolving credit facility contains customary covenants for borrowings of this type, including two financial covenants: (i) as of any date, for the period of four fiscal quarters ended on or immediately prior to such date, the ratio of consolidated debt for borrowed money to consolidated cash flow, each as defined in the revolving credit facility agreement, must not exceed 4.00 to 1.00; and (ii) as of any date, for the period of four fiscal quarters ended on or immediately prior to such date, the ratio of consolidated cash flow to the sum of interest payable on, and amortization of debt discount in respect of, all consolidated debt for borrowed money, as defined in the credit agreement, must not be less than 3.50 to 1.00.
Revolving credit facility, Financial covenant, Ratio of consolidated debt for borrowed money to consolidated cash flow	400.00%
Revolving credit facility, Financial covenant, Ratio of consolidated cash flow to the sum of interest payable and amortization of debt discount on all consolidated debt for borrowed money	350.00%
Revolving credit facility, Covenant compliance	At March 31, 2015, the Company was in compliance with all covenants.
Base Rate Borrowings
Debt Instruments
Interest rate that would have applied at year end under revolving credit facility	3.38%
Eurocurrency Rate Borrowings
Debt Instruments
Interest rate that would have applied at year end under revolving credit facility	1.18%
2.875% Senior Notes due August 2018 (2.875% Notes)
Debt Instruments
Debt issuance costs					2,000,000
Senior Notes, Face amount					250,000,000
Senior Notes, Interest rate					2.875%
Proceeds from issuance of Senior Notes					249,000,000
Senior Notes, Discount					1,000,000
Additional basis points for redemption of Senior Notes					0.25%
Repurchase percentage of principal amount with accrued and unpaid interest					101.00%
4.500% Senior Notes due August 2023 (4.500% Notes)
Debt Instruments
Debt issuance costs					2,000,000
Senior Notes, Face amount					250,000,000
Senior Notes, Interest rate					4.50%
Proceeds from issuance of Senior Notes					249,000,000
Senior Notes, Discount					1,000,000
Additional basis points for redemption of Senior Notes					0.30%
Repurchase percentage of principal amount with accrued and unpaid interest					101.00%
5.375% Senior Notes due December 2019 (5.375% Notes)
Debt Instruments
Senior Notes, Face amount							750,000,000
Senior Notes, Interest rate							5.375%
Additional basis points for redemption of Senior Notes							0.30%
Repurchase percentage of principal amount with accrued and unpaid interest							101.00%
6.125% Senior Notes due December 2014 (6.125% Notes)
Debt Instruments
Senior Notes, Face amount						500,000,000
Senior Notes, Interest rate						6.125%
Repayment of debt obligations						500,000,000
Multi-Currency Line of Credit
Debt Instruments
Borrowings outstanding	0
Amount pledged in support of bank guarantees and other local credit lines	$ 27,000,000	$ 49,000,000
Borrowings outstanding		less than $1 million