Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Consolidated Statements of Comprehensive Income [Abstract]
Net Income	$ 28,370	$ 29,723	$ 27,392
Other Comprehensive Loss
Net Unrealized Loss on Available-for-Sale Securities	(1,011)	(1,330)	(3,069)
Deferred Tax Benefit Related to Unrealized Losses	281	559	1,290
Reclassification Adjustment for Realized (Gain) Loss on Available-for-Sale Securities Included in Net Income	(131)	284	(275)
Tax Expense (Benefit) Related to Reclassification Adjustment	55	(119)	116
Change in Net Unrealized Loss on Available-for-Sale Securities, Net of Tax	(806)	(606)	(1,938)
Total Other Comprehensive Loss	(806)	(606)	(1,938)
Comprehensive Income	$ 27,564	$ 29,117	$ 25,454