Commitments (Purchase Commitments) (Details) (Raw Materials [Member], USD $)	12 Months Ended
Jan. 31, 2013
Raw Materials [Member]
Long-term Purchase Commitment [Line Items]
Purchase commitment	$ 6,194,000

The minimum amount the entity agreed to spend under the long-term purchase commitment.

No definition available.

Name:	us-gaap_LongTermPurchaseCommitmentAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration