XML 40 R30.htm IDEA: XBRL DOCUMENT v3.10.0.1

Commitments and Contingencies (Tables)

6 Months Ended

Jun. 30, 2018

Commitments and Contingencies Disclosure [Abstract]

Commitments and Letters of Credit

The following table sets forth our commitments and letters of credit as of the dates presented:

(dollars in thousands)	June 30, 2018				December 31, 2017
Commitments to extend credit	$	1,413,700			$	1,420,428
Standby letters of credit	80,709				80,918
Total	$	1,494,409			$	1,501,346

X

- Definition

Commitments and Letters of Credit [Table Text Block]

+ References

No definition available.

+ Details

Name:	stba_CommitmentsandLettersofCreditTableTextBlock
Namespace Prefix:	stba_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	us-gaap_CommitmentsAndContingenciesDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration