Fair Value Of Financial Instruments (Details) (USD $)												3 Months Ended	12 Months Ended
	Jan. 31, 2013	Jan. 31, 2013 Senior Notes	Sep. 30, 2012 Senior Notes	Jan. 31, 2012 Senior Notes	Jan. 31, 2013 Level 1 Senior Notes	Jan. 31, 2013 Level 1 Fair Value, Measurements, Recurring	Jan. 31, 2012 Level 1 Fair Value, Measurements, Recurring	Jan. 31, 2013 Level 2 Fair Value, Measurements, Recurring	Jan. 31, 2012 Level 2 Fair Value, Measurements, Recurring	Jan. 31, 2013 Level 3 Fair Value, Measurements, Recurring	Jan. 31, 2012 Level 3 Fair Value, Measurements, Recurring	Apr. 30, 2013 Subsequent Event	Jan. 31, 2013 Selling, General and Administrative Expenses	Jan. 31, 2013 Other Expense (Income)
Assets, Fair Value Disclosure [Abstract]
Foreign currency forward contracts								$ 19,835,000	$ 6,243,000
Liabilities, Fair Value Disclosure [Abstract]
Foreign currency forward contracts								19,628,000	11,226,000
Acquisition-related contingent consideration										18,147,000	15,506,000
Adjustments to the fair value of acquisition-related contingent consideration													2,600,000	800,000
Acquisition related contingent consideration paid												8,700,000
Fair value of deferred compensation plan assets	35,300,000
Fair value of deferred compensation plan liabilities	31,200,000
Convertible senior debentures, face value		350,000,000	350,000,000	0
Convertible debt, fair value disclosures					$ 363,900,000