Guarantees (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2013
Guarantees [Abstract]
Undrawn standby letters of credit outstanding	$ 2.0
Letter of credit, expiration term	1 year

Period remaining on line of credit facility before it terminates, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	us-gaap_LineOfCreditFacilityExpirationPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration