Commitments And Contingencies (Narrative) (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	12 Months Ended
	Jun. 30, 2003	Nov. 30, 2011	Nov. 30, 2010	Nov. 30, 2009	Dec. 31, 2011 Letters Of Credit One [Member]	Nov. 30, 2011 Letters Of Credit One [Member]	Dec. 31, 2011 Letters Of Credit Two [Member]	Nov. 30, 2011 Letters Of Credit Two [Member]	Dec. 31, 2011 Letters Of Credit Three [Member]	Nov. 30, 2011 Letters Of Credit Three [Member]	Dec. 31, 2011 Revolving Line Of Credit [Member]	Nov. 30, 2011 Revolving Line Of Credit [Member]	Dec. 31, 2011 Cash Borrowings [Member]	Nov. 30, 2011 Cash Borrowings [Member]
Commitments And Contingencies [Line Items]
Revolving credit facility amount outstanding					$ 13.0	$ 13.0	$ 1.0	$ 1.0	$ 0.4	$ 0.4			$ 100.0
Revolving credit facility, maximum capacity											250.0	20.0	250.0	150.0
Original land lease expiration date (in years)	51
Prepaid land lease rent	28.0
Prepaid land lease adjustments term (in years)	10
Rental expense		14.2	11.0	9.7
Lease expiration date		September 2019
Long-term income tax liabilities for uncertainty in income taxes		$ 20.8