Loans & Leases (Narrative) (Detail) (USD $)	3 Months Ended	6 Months Ended
Jun. 30, 2014	Jun. 30, 2014
Disclosure Loans & Leases Narrative [Abstract]
Significant Credit Rating Loans Threshold	$ 5,000,000	$ 5,000,000
Indirect Auto Loans Reclassified From Held For Investment To Held For Sale		265,000,000
Transfer For Loans Designated As Held For Sale	$ 1,236,000	$ 1,236,000

Relationship threshold on significant credits with ratings of special mention or substandard to determine if the credit should be reviewed on a quarterly basis.

No definition available.

Name:	susq_SignificantCreditRatingLoansThreshold
Namespace Prefix:	susq_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant