Investments Investments (Available for Sale) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 536,182	$ 514,237
Gross Unrealized Holding Gains	7,528	2,882
Gross Unrealized Holding Losses	2,932	6,868
Estimated Fair Value	540,778	510,251
U.S. Treasury securities and obligations of U.S. government agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	110	610
Gross Unrealized Holding Gains	2	2
Gross Unrealized Holding Losses	0	1
Estimated Fair Value	112	611
Obligations of states, municipalities and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	126,050	153,884
Gross Unrealized Holding Gains	4,164	2,010
Gross Unrealized Holding Losses	54	1,294
Estimated Fair Value	130,160	154,600
Corporate and other securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	108,757	97,889
Gross Unrealized Holding Gains	1,676	264
Gross Unrealized Holding Losses	310	1,401
Estimated Fair Value	110,123	96,752
Commercial mortgage and asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	164,341	151,137
Gross Unrealized Holding Gains	912	252
Gross Unrealized Holding Losses	841	1,522
Estimated Fair Value	164,412	149,867
Residential mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	136,924	110,717
Gross Unrealized Holding Gains	774	354
Gross Unrealized Holding Losses	1,727	2,650
Estimated Fair Value	$ 135,971	$ 108,421

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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-Publisher FASB
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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 50
-Paragraph 2
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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
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