Letters of Credit and Off Balance Sheet Liabilities (Narrative) (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Letters of Credit and Off Balance Sheet Liabilities [Abstract]
Outstanding standby letters of credit	$ 1.8	$ 1.6

Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments.

No definition available.

Name:	us-gaap_ContractualObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant