Derivatives And Financial Instruments (Schedule Of Other Comprehensive Income ("OCI") Related To Cash Flow Hedges) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2011	Oct. 31, 2010	Oct. 31, 2011	Oct. 31, 2010
Derivatives And Financial Instruments [Abstract]
Accumulated OCI related to cash flow hedges, beginning of the period	$ 573	$ 747	$ 748	$ 785
Unrealized (losses) gains on cash flow hedges	(1,591)	3,575	4,091	3,191
Reclassification adjustment for losses (gains) included in net income/(loss)	1,044	(1,003)	(4,509)	(619)
Changes in accumulated OCI on cash flow hedges, before tax	(547)	2,572	(418)	2,572
Other comprehensive income (loss) attributable to noncontrolling interest	465	(400)	157	(419)
Deferred income tax benefit (provision)	41	(23)	45	(42)
Changes in accumulated OCI on cash flow hedges, net of tax	(41)	2,149	(216)	2,111
Accumulated OCI related to cash flow hedges, end of the period	$ 532	$ 2,896	$ 532	$ 2,896