Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Consolidated Statements of Comprehensive Income (Unaudited) [Abstract]
Net Income	$ 12,000	$ 8,581	$ 32,491	$ 24,589
Other Comprehensive Income
Increase in Net Unrealized (Loss) Gain on Available-for-Sale Securities	(1,679)	322	(9,486)	1,106
Deferred Tax Benefit (Expense) Related to Unrealized Gains	496	(135)	2,816	(465)
Reclassification Adjustment for Realized Losses (Gains) on Available-for-Sale Securities Included in Net Income	0	0	1,330	(131)
Deferred Tax Benefit (Expense) Related to Reclassification Adjustment	0	0	(405)	55
Change in Net Unrealized (Losses) Gains on Available-for-Sale Securities, Net of Tax	(1,183)	187	(5,745)	565
Total Other Comprehensive (Loss) Income	(1,183)	187	(5,745)	565
Comprehensive Income	$ 10,817	$ 8,768	$ 26,746	$ 25,154

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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