Fair Value Of Financial Assets And Liabilities (Carrying Value And Fair Value Of Debt) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Carrying Value	$ 2,607,818	$ 1,772,287
Total Debt, Carrying Value	2,607,818	2,160,739
Trade Receivables Securitization [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Carrying Value	295,000	295,000
Senior Subordinated Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Carrying Value	215,446	215,446
Other long-term debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Carrying Value	2,475	6,150
Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Debt	2,670,949	2,237,065
Estimate of Fair Value, Fair Value Disclosure [Member] | Trade Receivables Securitization [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Debt	295,000	295,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Revolving Credit Borrowings [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Debt	44,077	49,810
Estimate of Fair Value, Fair Value Disclosure [Member] | 2.85% Senior Notes Maturing October 2013 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Debt	303,413	314,881
Estimate of Fair Value, Fair Value Disclosure [Member] | 4.5% Senior Notes Maturing September 2014 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Debt	421,582	429,530
Estimate of Fair Value, Fair Value Disclosure [Member] | 3.25% Senior Notes Due October 2015 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Debt	263,702	260,325
Estimate of Fair Value, Fair Value Disclosure [Member] | 2.95% Senior Notes Maturing June 2016 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Debt	262,954	257,821
Estimate of Fair Value, Fair Value Disclosure [Member] | 1.65% Senior Notes Maturing February 2018 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Debt	325,401	0
Estimate of Fair Value, Fair Value Disclosure [Member] | 2.375% Senior Notes Maturing February 2020 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Debt	274,432	0
Estimate of Fair Value, Fair Value Disclosure [Member] | 2.90% Senior Notes Maturing November 2022 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Debt	248,404	0
Estimate of Fair Value, Fair Value Disclosure [Member] | Senior Subordinated Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Debt	229,381	234,836
Estimate of Fair Value, Fair Value Disclosure [Member] | Other long-term debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Debt	2,603	6,410
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial Paper [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Debt	0	388,452
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total Debt, Carrying Value	2,607,818	2,160,739
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Trade Receivables Securitization [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Carrying Value	295,000	295,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Revolving Credit Borrowings [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Carrying Value	44,077	49,810
Carrying (Reported) Amount, Fair Value Disclosure [Member] | 2.85% Senior Notes Maturing October 2013 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Carrying Value	302,466	306,677
Carrying (Reported) Amount, Fair Value Disclosure [Member] | 4.5% Senior Notes Maturing September 2014 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Carrying Value	399,856	399,760
Carrying (Reported) Amount, Fair Value Disclosure [Member] | 3.25% Senior Notes Due October 2015 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Carrying Value	249,811	249,736
Carrying (Reported) Amount, Fair Value Disclosure [Member] | 2.95% Senior Notes Maturing June 2016 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Carrying Value	249,778	249,708
Carrying (Reported) Amount, Fair Value Disclosure [Member] | 1.65% Senior Notes Maturing February 2018 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Carrying Value	324,471	0
Carrying (Reported) Amount, Fair Value Disclosure [Member] | 2.375% Senior Notes Maturing February 2020 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Carrying Value	274,706	0
Carrying (Reported) Amount, Fair Value Disclosure [Member] | 2.90% Senior Notes Maturing November 2022 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Carrying Value	249,732	0
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Senior Subordinated Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Carrying Value	215,446	215,446
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Other long-term debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Carrying Value	2,475	6,150
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial Paper [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper, Carrying Value	$ 0	$ 388,452