Investments Investments (Available for Sale) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 577,183	$ 514,237
Gross Unrealized Holding Gains	14,540	2,882
Gross Unrealized Holding Losses	1,646	6,868
Estimated Fair Value	590,077	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	3	2
Gross Unrealized Holding Losses	0	1
Estimated Fair Value	113	611
Obligations of states, municipalities and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	125,619	153,884
Gross Unrealized Holding Gains	6,344	2,010
Gross Unrealized Holding Losses	2	1,294
Estimated Fair Value	131,961	154,600
Corporate and other securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	125,873	97,889
Gross Unrealized Holding Gains	3,572	264
Gross Unrealized Holding Losses	229	1,401
Estimated Fair Value	129,216	96,752
Commercial mortgage and asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	175,355	151,137
Gross Unrealized Holding Gains	2,995	252
Gross Unrealized Holding Losses	485	1,522
Estimated Fair Value	177,865	149,867
Residential mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	150,226	110,717
Gross Unrealized Holding Gains	1,626	354
Gross Unrealized Holding Losses	930	2,650
Estimated Fair Value	$ 150,922	$ 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).

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