Fair Value Of Financial Assets And Liabilities (Carrying Value And Fair Value Of Debt) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Mar. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term debt, carrying value	$ 53,000	$ 387,866
Long-term debt, carrying value	2,408,761	2,107,096
Total debt, carrying value	2,461,761	2,494,962
Total debt, fair value	2,470,809	2,489,195
Commercial paper [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term debt, carrying value	53,000	387,866
Short-term debt, fair value	53,000	387,866
Trade receivables securitization [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, carrying value	295,000	295,000
Long-term debt, fair value	295,000	295,000
Revolving Credit Borrowings [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, carrying value	64,609	62,286
Long-term debt, fair value	64,609	62,286
4.5% Senior Notes Maturing September 2014 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, carrying value	399,976	399,952
Long-term debt, fair value	403,036	407,092
3.25% Senior Notes Maturing October 2015 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, carrying value	249,906	249,887
Long-term debt, fair value	257,260	258,630
2.95% Senior Notes Maturing June 2016 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, carrying value	249,866	249,848
Long-term debt, fair value	258,803	259,257
1.65% Senior Notes Maturing February 2018 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, carrying value	324,607	324,579
Long-term debt, fair value	323,307	319,098
2.375% Senior Notes Maturing February 2020 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, carrying value	274,759	274,748
Long-term debt, fair value	269,954	265,600
2.90% Senior Notes Maturing November 2022 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, carrying value	249,766	249,760
Long-term debt, fair value	241,535	233,230
3.65% Senior Notes Maturing July 2024 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, carrying value	299,417	0
Long-term debt, fair value	303,372	0
Other long-term debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, carrying value	855	1,036
Long-term debt, fair value	$ 933	$ 1,136