Quarterly Results (Unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
	Nov. 30, 2011	Aug. 31, 2011	May 31, 2011	Feb. 28, 2011	Nov. 30, 2010	Aug. 31, 2010	May 31, 2010	Feb. 28, 2010	Nov. 30, 2011	Nov. 30, 2010	Nov. 30, 2009
Consolidated quarterly results
Revenues	$ 479,872,000	$ 367,316,000	$ 271,738,000	$ 196,940,000	$ 450,963,000	$ 501,003,000	$ 374,052,000	$ 263,978,000	$ 1,315,866,000	$ 1,589,996,000	$ 1,824,850,000
Gross Profit	72,941,000	63,579,000	20,570,000	25,279,000	87,391,000	88,436,000	66,217,000	36,545,000
Pretax Income (loss)	11,411,000	(9,649,000)	(68,804,000)	(114,126,000)	15,442,000	(6,697,000)	(30,609,000)	(54,504,000)	(181,168,000)	(76,368,000)	(311,184,000)
Net income (loss)	13,911,000	(9,649,000)	(68,504,000)	(114,526,000)	17,442,000	(1,397,000)	(30,709,000)	(54,704,000)	(178,768,000)	(69,368,000)	(101,784,000)
Basic and Diluted earnings (loss) per share	$ 0.18	$ (0.13)	$ (0.89)	$ (1.49)	$ 0.23	$ (0.02)	$ (0.40)	$ (0.71)	$ (2.32)	$ (0.90)	$ (1.33)
Quarterly results (Textual) [Abstract]
Pretax, noncash inventory impairment charges	1,300,000	300,000	20,100,000	1,000,000	1,600,000	1,400,000		6,800,000	22,730,000	9,815,000	120,848,000
Land option contract abandonment charges	1,000,000	800,000	500,000	800,000	1,600,000	2,000,000		6,500,000	3,061,000	10,110,000	47,301,000
Loss on loan guaranty			14,600,000	22,800,000					30,765,000
Gain on loan guaranty	6,600,000
Joint ventures impairment charges				$ 53,700,000					$ 53,700,000	$ 0	$ 38,500,000