Notes Payable (Narratives) (Details) - USD ($)	3 Months Ended		6 Months Ended
	May 31, 2016	May 31, 2015	May 31, 2016	May 31, 2015	Nov. 30, 2015
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 275,000,000		$ 275,000,000
Letters of credit outstanding	$ 35,000,000		35,000,000		$ 33,400,000
Proceeds from Issuance of Senior Long-term Debt			$ 0	$ 250,000,000
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities	8,402,000	8,402,000	8,402,000	8,402,000
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	$ 40,100,000		$ 40,100,000
Long-term Debt, Maturities, Repayments of Principal in Year Two	266,400,000		266,400,000
Long-term Debt, Maturities, Repayments of Principal in Year Three	300,000,000		300,000,000
Long-term Debt, Maturities, Repayments of Principal in Year Four	630,000,000		630,000,000
Long-term Debt, Maturities, Repayments of Principal in Year Five	350,000,000		350,000,000
Long-term Debt, Maturities, Repayments of Principal after Year Five	1,050,000,000		1,050,000,000
Inventories pledged to collateralize mortgages and land contracts, carrying value	144,100,000		144,100,000
Letter of Credit [Member]
Debt Instrument [Line Items]
Unsecured revolving credit facility, maximum borrowing capacity	137,500,000		137,500,000
Line of Credit Facility, Amount Outstanding	31,557,000.000		31,557,000.000
Letters of credit outstanding	3,400,000		3,400,000		$ 9,100,000
Unsecured revolving credit facility, remaining borrowing capacity	105,900,000		$ 105,900,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Unsecured revolving credit facility, expiration date			Aug. 07, 2019
Unsecured revolving credit facility, maximum borrowing capacity	450,000,000		$ 450,000,000
Line of Credit Facility, Amount Outstanding	0		0
Unsecured revolving credit facility, remaining borrowing capacity	$ 243,400,000		$ 243,400,000
Revolving Credit Facility [Member] | Minimum [Member]
Debt Instrument [Line Items]
Line of credit facility, unused capacity, commitment fee percentage			0.30%
Revolving Credit Facility [Member] | Maximum [Member]
Debt Instrument [Line Items]
Line of credit facility, unused capacity, commitment fee percentage			0.50%
Convertible Notes Payable [Member] | Convertible Senior Notes Due Two Thousand Nineteen At One Point Three Seven Five Percent [Member] [Member]
Debt Instrument [Line Items]
Senior notes, rate	1.375%		1.375%		1.375%
Debt Conversion, Converted Instrument, Shares Issued			36.5297
Debt instrument, convertible, conversion price	$ 27.37		$ 27.37
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities			8,401,831
Senior Notes [Member] | Senior notes due September 15, 2017 at 9.10%
Debt Instrument [Line Items]
Senior notes, rate	9.10%		9.10%		9.10%
Senior Notes [Member] | Senior Notes Due Two Thousand Nineteen at Four Point Seven Five Percent [Member]
Debt Instrument [Line Items]
Senior notes, rate	4.75%		4.75%		4.75%
Senior Notes [Member] | Senior notes due March 15, 2020 at 8.00%
Debt Instrument [Line Items]
Senior notes, rate	8.00%		8.00%		8.00%
Senior Notes [Member] | Senior notes due September 15, 2022 at 7.50%
Debt Instrument [Line Items]
Senior notes, rate	7.50%		7.50%		7.50%
Senior Notes [Member] | Senior Notes Due Two Thousand Twenty Three At Seven Point Six Two Five Percent [Domain]
Debt Instrument [Line Items]
Senior notes, rate	7.625%		7.625%		7.625%