Fair Value Disclosures Fair Value Disclosures (Level 4 Inv Impair inputs) (Details 3) (Details) (Operating communities [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012
Minimum [Member]
Fair value inputs, assets, quantitative information [Line Items]
Average selling price	$ 0	$ 303	$ 501	$ 175	$ 413	$ 344
Sales pace (in ones)	0	15	11	4	6	1
Discount rate	0.00%	15.30%	18.30%	14.00%	17.50%	13.00%
Maximum [Member]
Fair value inputs, assets, quantitative information [Line Items]
Average selling price	$ 0	$ 307	$ 536	$ 571	$ 472	$ 2,287
Sales pace (in ones)	0	15	11	12	17	25
Discount rate	0.00%	15.30%	18.30%	17.50%	17.50%	18.80%