Financial Instruments (Narrative) (Details) (USD $)	12 Months Ended		1 Months Ended	12 Months Ended			2 Months Ended	12 Months Ended		1 Months Ended
	Nov. 30, 2012	Nov. 30, 2011	Mar. 31, 2006 Interest Rate Swap [Member]	Nov. 30, 2012 Maximum [Member]	Nov. 30, 2012 Minimum [Member]	Nov. 30, 2012 7 Day Maximum [Member]	Jun. 30, 2011 Interest Rate Swap [Member]	Nov. 30, 2012 Interest Rate Swap [Member]	Nov. 30, 2012 Interest Rate Swap [Member] Treasury Lock [Member]	Mar. 31, 2006 5.20% Medium-Term Notes Due 2015 [Member]
Derivative [Line Items]
Foreign currency to purchase or sell	$ 188,800,000	$ 127,600,000
Notional amount of foreign currency exchange contracts with a duration under 7 days						84,900,000
Maximum time frame for short-term foreign exchange contracts	7 days
Maturity period for remaining foreign currency contracts (in months)				12 months	1 month
Total notional amount of interest rate swap contracts			100,000,000				200,000,000		50,000,000
Anticipated issuance, next twelve months								50,000,000
Interest on interest rate swap contracts			5.20%						1.90%
Cash flow hedges settled in cash for gain (loss)							(200,000)
Weighted average fixed interest rate on issuance of notes							4.01%
Aggregate principal amount							250,000,000
Amortization period interest expense (in years)								10 years
Basis spread on variable interest rate derivative contracts, percentage below LIBOR			0.05%
Maturity date of interest rate swap contracts			December 2015
Derivative instruments fair value hedge			100,000,000
Medium-term notes due										200,000,000
Debt instrument interest rate										5.20%
Debt instrument maturity year										2015
Hedge ineffectiveness recognized on interest rate swaps			0
Other comprehensive income (loss) expected to be reclassified in income in next 12 months	(2,800,000)
Cost of long-term investments	$ 69,600,000	$ 59,700,000