Mortgages and Notes Payable (Schedule of Mortages and Notes Payable) (Details) (USD $)			3 Months Ended								0 Months Ended						0 Months Ended				0 Months Ended																		0 Months Ended
	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2013 Senior notes due February 1, 2014 at 5 3/4%	Nov. 30, 2013 Senior notes due January 15, 2015 at 5 7/8%	Jan. 29, 2013 Convertible senior notes due February 1, 2019 at 1.375%	Nov. 30, 2013 Convertible Senior Notes Due Two Thousand Nineteen At One Point Three Seven Five Percent [Member]	Nov. 30, 2013 Mortgages and land contracts due to land sellers and other loans (at interest rates of 7% at November 30, 2013 and 6% to 7% at November 30, 2012)	Nov. 30, 2012 Mortgages and land contracts due to land sellers and other loans (at interest rates of 7% at November 30, 2013 and 6% to 7% at November 30, 2012)	Nov. 30, 2012 Mortgages and land contracts due to land sellers and other loans (at interest rates of 7% at November 30, 2013 and 6% to 7% at November 30, 2012) Minimum	Nov. 30, 2012 Mortgages and land contracts due to land sellers and other loans (at interest rates of 7% at November 30, 2013 and 6% to 7% at November 30, 2012) Maximum	Jul. 31, 2012 Senior Notes [Member]	Feb. 07, 2012 Senior Notes [Member]	Oct. 29, 2013 Senior Notes [Member] Senior notes due February 1, 2014 at 5 3/4%	Nov. 30, 2013 Senior Notes [Member] Senior notes due February 1, 2014 at 5 3/4%	Nov. 30, 2012 Senior Notes [Member] Senior notes due February 1, 2014 at 5 3/4%	Jan. 28, 2004 Senior Notes [Member] Senior notes due February 1, 2014 at 5 3/4%	Oct. 29, 2013 Senior Notes [Member] Senior notes due January 15, 2015 at 5 7/8%	Nov. 30, 2013 Senior Notes [Member] Senior notes due January 15, 2015 at 5 7/8%	Nov. 30, 2012 Senior Notes [Member] Senior notes due January 15, 2015 at 5 7/8%	Dec. 15, 2004 Senior Notes [Member] Senior notes due January 15, 2015 at 5 7/8%	Oct. 29, 2013 Senior Notes [Member] Senior notes due June 15, 2015 at 6 1/4%	Nov. 30, 2013 Senior Notes [Member] Senior notes due June 15, 2015 at 6 1/4%	Nov. 30, 2012 Senior Notes [Member] Senior notes due June 15, 2015 at 6 1/4%	Jun. 02, 2005 Senior Notes [Member] Senior notes due June 15, 2015 at 6 1/4%	Nov. 30, 2013 Senior Notes [Member] Senior notes due September 15, 2017 at 9.10%	Nov. 30, 2012 Senior Notes [Member] Senior notes due September 15, 2017 at 9.10%	Nov. 30, 2013 Senior Notes [Member] Senior notes due June 15, 2018 at 7 1/4%	Nov. 30, 2012 Senior Notes [Member] Senior notes due June 15, 2018 at 7 1/4%	Apr. 03, 2006 Senior Notes [Member] Senior notes due June 15, 2018 at 7 1/4%	Nov. 30, 2013 Senior Notes [Member] Senior notes due March 15, 2020 at 8.00%	Nov. 30, 2012 Senior Notes [Member] Senior notes due March 15, 2020 at 8.00%	Feb. 07, 2012 Senior Notes [Member] Senior notes due March 15, 2020 at 8.00%	Nov. 30, 2013 Senior Notes [Member] Senior notes due December 15, 2021 at 7.00%	Oct. 29, 2013 Senior Notes [Member] Senior notes due December 15, 2021 at 7.00%	Nov. 30, 2012 Senior Notes [Member] Senior notes due December 15, 2021 at 7.00%	Nov. 30, 2013 Senior Notes [Member] Senior notes due September 15, 2022 at 7.50%	Nov. 30, 2012 Senior Notes [Member] Senior notes due September 15, 2022 at 7.50%	Jul. 31, 2012 Senior Notes [Member] Senior notes due September 15, 2022 at 7.50%	Jan. 29, 2013 Convertible Notes Payable [Member] Convertible senior notes due February 1, 2019 at 1.375%	Nov. 30, 2013 Convertible Notes Payable [Member] Convertible senior notes due February 1, 2019 at 1.375%	Nov. 30, 2012 Convertible Notes Payable [Member] Convertible senior notes due February 1, 2019 at 1.375%
Debt Instrument [Line Items]
Proceeds from Convertible Debt																																							$ 222,700,000
Extinguishment of Debt, Amount			56,300,000	11,000,000							244,900,000	340,000,000	19,700,000				91,100,000				37,000,000
Senior notes, rate					1.375%	1.375%	7.00%		6.00%	7.00%				5.75%	5.75%	5.75%		5.88%	5.88%	5.875%		6.25%	6.25%	6.25%			7.25%	7.25%	7.25%	8.00%	8.00%	8.00%	7.00%	7.00%		7.50%	7.50%	7.50%
Mortgages and notes payable	$ 2,150,498,000	$ 1,722,815,000					$ 13,615,000	$ 52,311,000						$ 0	$ 75,911,000			$ 0	$ 101,999,000			$ 199,864,000	$ 236,826,000		$ 262,048,000	$ 261,430,000	$ 299,261,000	$ 299,129,000		$ 345,710,000	$ 345,209,000		$ 450,000,000		$ 0	$ 350,000,000	$ 350,000,000			$ 230,000,000	$ 0