Income Taxes (Details Textual) (USD $)	3 Months Ended		12 Months Ended
	Apr. 30, 2012	Apr. 30, 2011	Jan. 31, 2012
Income Taxes (Textual) [Abstract]
Income tax expense (benefit)	$ 9,573,000	$ 17,749,000
Net operating loss carryforward			170,233,000
Net operating loss carryforwards expiration dates			Years ending January 31, 2026 through January 31, 2032
Charitable contribution deduction carryforward			30,401,000
Charitable contribution deduction carryforward expiration dates			Years ending January 31, 2013 through January 31, 2017
General Business credits carryovers			20,212,000
General Business credits carryovers expiration dates			Years ending January 31, 2013 through January 31, 2032
Alternative Minimum Tax credits			27,452,000
Net deferred tax asset unrecognized			$ 17,265,000