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