Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Consolidated Statements of Comprehensive Income (Unaudited) [Abstract]
Net Income	$ 9,941	$ 7,821
Other Comprehensive Income
Increase in Net Unrealized Loss on Available-for-Sale Securities	(5,288)	(114)
Deferred Tax Benefit Related to Unrealized Losses	1,563	48
Change in Net Unrealized Loss on Available-for-Sale Securities, Net of Tax	(3,725)	(66)
Total Other Comprehensive Loss	(3,725)	(66)
Comprehensive Income	$ 6,216	$ 7,755