Short-Term Debt and Short-Term Restricted Cash and Cash Equivalents (Details) (USD $) In Millions, unless otherwise specified		6 Months Ended
	Oct. 31, 2010	Apr. 30, 2011 Line of Credit [Member]	Apr. 30, 2011 Line Of Credit Amendment [Member]
Line of Credit Facility [Abstract]
Credit facility initiation date		2007-05-11	2009-08-17
Line of credit facility, revolving credit, description		On May 11, 2007, we entered into a five-year credit agreement, which provides for a 300 million unsecured credit facility that will expire on May 11, 2012. On September 8, 2009, we entered into an Accession Agreement, increasing the credit facility from 300 million to 330 million. The company may use amounts borrowed under the facility for general corporate purposes. As of April 30, 2011 the company has no borrowings outstanding under the facility.
Line of credit facility, term (in years)		5
Credit facility - initial borrowing capacity		$ 300
Line of credit facility, expiration date		2012-05-11
Credit facility - Accession Agreement initiation date		2009-09-08
Credit facility - borrowing capacity		330
Line of credit facility, amount outstanding		0
Line of credit facility, covenant terms			On August 17, 2009 the credit facility agreement was amended to provide additional financing flexibility in advance of the acquisition of Varian, Inc. The amendment allowed for incremental indebtedness to be excluded from the leverage ratio covenant until March 1, 2011 and reduced the basket for other secured financings permitted from 300 million to 75 million during this period. The amendment has since expired and we were in compliance with the covenants for the credit facility during the three months ended April 30, 2011.
Other secured financing maximum		300	75
Short-term restricted cash and cash equivalents	$ 1,550