EARNINGS PER COMMON SHARE (Additional Information) (Detail)	12 Months Ended
Dec. 31, 2013
Percentage Of Mandatory Convertible Trust Preferred Securities	6.00%

Percentage Of Mandatory Convertible Trust Preferred Securities.

No definition available.

Name:	svfb_PercentageOfMandatoryConvertibleTrustPreferredSecurities
Namespace Prefix:	svfb_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration