Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2010
Current
Federal	$ (9,252)	$ (3,780)	$ 2,327
State	(48)	4,382	5,320
Current income tax expense (benefit)	(9,300)	602	7,647
Deferred
Federal	(42,342)	63,664	(16,554)
State	(12,702)	5,860	(1,233)
Deferred income tax expense (benefit)	(55,044)	69,524	(17,787)
Total income tax expense (benefit)	$ (64,344)	$ 70,126	$ (10,140)