Other Assets (Details) (USD $)	Feb. 28, 2013		Nov. 30, 2012		Jan. 29, 2013 Convertible senior notes due February 1, 2019 at 1.375%
Other Assets [Abstract]
Cash surrender value of insurance contracts	$ 67,276,000		$ 64,757,000
Debt issuance costs	21,159,000	[1]	14,563,000	[1]
Property and equipment, net	7,887,000		7,920,000
Prepaid expenses	6,256,000		7,810,000
Total	102,578,000		95,050,000
Debt Instrument [Line Items]
Debt Instrument, Face Amount					$ 230,000,000

[1] The increase in debt issuance costs as of February 28, 2013 compared to November 30, 2012 primarily reflected the costs associated with our issuance of the $230 Million Convertible Senior Notes during the three months ended February 28, 2013.