Investments (Components of Other Comprehensive Income Related to Available-For-Sale Securities) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Apr. 30, 2012	Apr. 30, 2011
Other Comprehensive Income Related to Available-For-Sale Securities [Roll Forward]
Accumulated OCI related to available-for-sale securities, beginning of the period	$ (3,760)	$ 17,871
Unrealized gains on available-for-sale securities	0	161
Reclassification adjustment for gains included in net loss	(34)	(65)
Changes in accumulated OCI on available-for-sale securities, before tax	(34)	96
Deferred income tax benefit	3,794	0
Changes in accumulated OCI on available-for-sale securities, net of tax	3,760	96
Accumulated OCI related to available-for-sale securities, end of the period	$ 0	$ 17,967

Accumulated appreciation or loss, net of tax, in value of the total of available-for-sale securities at the end of an accounting period.

+ References+ Details

Gross appreciation or the gross loss in value of the total unsold securities, after tax, attributable to the parent entity.

+ References

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- Definition

Pre tax reclassification adjustment for gains or losses realized upon the sale of securities.

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+ Details

- Definition

Gross appreciation or the gross loss in value of the total of unsold available-for-sale securities during the period being reported (except when designated as a fair value hedge).

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+ Details

- Definition

Tax effect on gross appreciation or the gross loss in value of the total of unsold securities during the period being reported on.

+ References+ Details