Information on Geographic Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Apr. 30, 2011	Jan. 31, 2011	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2010
Revenues
Revenues	$ 632,826	$ 554,319	$ 373,681	$ 321,955	$ 427,785	$ 394,305	$ 319,675	$ 334,116	$ 1,882,781	$ 1,475,881	$ 1,494,771
Income (loss) before income taxes
Income (loss) before income taxes	60,749	42,952	15,649	(6,408)	15,277	3,888	(31,484)	(17,047)	112,942	(29,366)	(117,187)
Total assets
Total assets	6,181,044				5,055,246				6,181,044	5,055,246
North [Member]
Revenues
Revenues									513,724	381,569	407,723
Income (loss) before income taxes
Income (loss) before income taxes									71,836	42,525	(2,296)
Total assets
Total assets	1,205,900				1,060,215				1,205,900	1,060,215
Mid-Atlantic [Member]
Revenues
Revenues									564,434	499,747	488,359
Income (loss) before income taxes
Income (loss) before income taxes									67,768	57,606	33,946
Total assets
Total assets	1,304,798				1,160,926				1,304,798	1,160,926
South [Member]
Revenues
Revenues									366,701	285,012	264,321
Income (loss) before income taxes
Income (loss) before income taxes									18,000	(25,936)	(35,193)
Total assets
Total assets	821,001				760,097				821,001	760,097
West [Member]
Revenues
Revenues									437,922	309,553	334,368
Income (loss) before income taxes
Income (loss) before income taxes									39,383	(27,113)	(11,895)
Total assets
Total assets	913,699				650,844				913,699	650,844
Corporate and other [Member]
Revenues
Revenues
Income (loss) before income taxes
Income (loss) before income taxes									(84,045)	(76,448)	(101,749)
Total assets
Total assets	$ 1,935,646				$ 1,423,164				$ 1,935,646	$ 1,423,164