Inventory Inventory (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended						6 Months Ended		12 Months Ended
	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Apr. 30, 2011	Jan. 31, 2011	Apr. 30, 2012	Apr. 30, 2011	Oct. 31, 2011
Number of Operating Communities Tested	115	113	114	129	142	143
Number of Communities	2	8	3	2	9	6
Fair Value of the Impaired Inventory	$ 22,962	$ 49,758	$ 3,367	$ 867	$ 40,765	$ 56,105
Inventory Write-down	2,008				12,922		10,128	18,048
Operating communities [Member]
Inventory Write-down	$ 2,560	$ 6,425	$ 710	$ 175	$ 10,725	$ 5,475	$ 8,985	$ 16,200	$ 17,085