Fair Value Measurement (Details Textual) (USD $)	12 Months Ended
Jan. 31, 2013	Jan. 31, 2012
Fair Value Measurement (Textual) [Abstract]
Transfers between levels of the fair value hierarchy of its assets or liabilities measured at fair value	$ 0	$ 0

Transfers between levels assets or liabilities measured fair value.

No definition available.

Name:	srna_TransfersBetweenLevelsAssetsOrLiabilitiesMeasuredFairValue
Namespace Prefix:	srna_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration