Share-Based Compensation (Narrative) (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) $ / shares	Dec. 31, 2015 USD ($) $ / shares	May 07, 2015 shares	May 31, 2012 shares	May 31, 2005 shares
Nonemployee director annual stock grants | shares	20,000
Share-based compensation expense | $	$ 2,612	$ 1,732	$ 2,134
Weighted Average Fair Value Per Share, Options granted | $ / shares	$ 5.76	$ 3.65	$ 4.74
Weighted Average Remaining Contractual Life (Years), Options outstanding	3 years 4 months 22 days
Number of Shares Authorized, Available to Issue and Outstanding | shares	1,810,850
Unrecognized compensation cost | $	$ 617
Aggregate Intrinsic Value, Options exercised | $	$ 2,314	$ 4,730	$ 5,551
Aggregate Intrinsic Value, Per Share, Options exercised | $ / shares	$ 13.55	$ 7.06	$ 12.69
2012 Plan [Member]
Shares available for grants | shares	951,668			3,000,000	1,500,000
Stock Option Plan, Award Vesting Period	5 years
Common stock on date granted term period, years	10
Weighted Average Fair Value Per Share, Options granted | $ / shares	$ 5.76
2005 Plan [Member]
Shares available for grants | shares	0					1,500,000
Stock Option Plan, Award Vesting Period	10 years
Common stock on date granted term period, years	10
Expected To Be Recognized During 2016 [Member]
Unrecognized compensation cost | $	$ 552
Expected To Be Recognized During 2017 [Member]
Unrecognized compensation cost | $	$ 65
Prior To Shareholder Approval of Increase [Member]
Nonemployee director annual stock grants | shares	15,000