Short-term Borrowings (Schedule of Short Term Borrowings) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Lines Of Credit Facility
Weighted daily outstanding amount	$ 28,832	$ 28,608	$ 27,906	$ 27,472
Weighted average interest rates	1.44%	1.32%	1.44%	1.35%

Average amount borrowed under the credit facility during the period.

No definition available.

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