Equity Incentive Plans (Schedule of Stock-option Expense to be Recognized in the Future) (Details) $ in Thousands	Dec. 31, 2017 USD ($)
Share-based Compensation [Abstract]
Stock option expense to be recognized in 2018	$ 291
Stock option expense to be recognized in 2019	4
Stock option expense to be recognized in 2020	4
Total Compensation Cost To Be Recognized, Stock Options	$ 299

Unrecognized cost of unvested options awarded to employees as compensation.

No definition available.

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant