Investments Reconciliation, Investments by Category (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	$ 842,487
US Government and Government Agencies and Authorities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	237,809	$ 151,656
Available-for-sale Securities, Gross Unrealized Gain, Accumulated in Investments	275	189
Available-for-sale Securities, Gross Unrealized Loss, Accumulated in Investments	2,193	1,893
Available-for-sale Securities, Debt Securities	235,891	149,952
Foreign Government Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	2,022	2,031
Available-for-sale Securities, Gross Unrealized Gain, Accumulated in Investments	14	30
Available-for-sale Securities, Gross Unrealized Loss, Accumulated in Investments	0	0
Available-for-sale Securities, Debt Securities	2,036	2,061
US States and Political Subdivisions Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	200,706	170,636
Available-for-sale Securities, Gross Unrealized Gain, Accumulated in Investments	1,929	1,027
Available-for-sale Securities, Gross Unrealized Loss, Accumulated in Investments	1,123	2,551
Available-for-sale Securities, Debt Securities	201,512	169,112
Public Utility, Bonds
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	20,215	7,687
Available-for-sale Securities, Gross Unrealized Gain, Accumulated in Investments	127	116
Available-for-sale Securities, Gross Unrealized Loss, Accumulated in Investments	85	73
Available-for-sale Securities, Debt Securities	20,257	7,730
All Other Corporate Bonds
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	287,025	164,424
Available-for-sale Securities, Gross Unrealized Gain, Accumulated in Investments	1,746	1,238
Available-for-sale Securities, Gross Unrealized Loss, Accumulated in Investments	1,209	1,126
Available-for-sale Securities, Debt Securities	287,562	164,536
Redeemable Preferred Stock
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	755	1,182
Available-for-sale Securities, Gross Unrealized Gain, Accumulated in Investments	11	5
Available-for-sale Securities, Gross Unrealized Loss, Accumulated in Investments	74	62
Available-for-sale Securities, Debt Securities	692	1,125
Fixed Maturities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	763,434	497,616
Available-for-sale Securities, Gross Unrealized Gain, Accumulated in Investments	4,125	2,605
Available-for-sale Securities, Gross Unrealized Loss, Accumulated in Investments	4,704	5,705
Available-for-sale Securities, Debt Securities	762,855	494,516
Mutual Fund
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Equity Securities, Amortized Cost Basis	29,079
Available-for-sale Securities, Gross Unrealized Gain, Accumulated in Investments	2,845
Available-for-sale Securities, Gross Unrealized Loss, Accumulated in Investments	0
Available-for-sale Securities, Equity Securities	31,924
Public Utility, Equities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Equity Securities, Amortized Cost Basis	1,343	1,343
Available-for-sale Securities, Gross Unrealized Gain, Accumulated in Investments	359	164
Available-for-sale Securities, Gross Unrealized Loss, Accumulated in Investments	0	0
Available-for-sale Securities, Equity Securities	1,702	1,507
Other Common Stock
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Equity Securities, Amortized Cost Basis	18,856	19,815
Available-for-sale Equity Securities, Accumulated Gross Unrealized Gain, before Tax	9,093
Available-for-sale Securities, Gross Unrealized Gain, Accumulated in Investments		4,552
Available-for-sale Securities, Gross Unrealized Loss, Accumulated in Investments	47	319
Available-for-sale Securities, Equity Securities	27,902	24,048
Nonredeemable Preferred Stock
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Equity Securities, Amortized Cost Basis	1,718	2,916
Available-for-sale Securities, Gross Unrealized Gain, Accumulated in Investments	53	10
Available-for-sale Securities, Gross Unrealized Loss, Accumulated in Investments	4	83
Available-for-sale Securities, Equity Securities	1,767	2,843
Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Equity Securities, Amortized Cost Basis	50,996	24,074
Available-for-sale Securities, Gross Unrealized Gain, Accumulated in Investments	12,350	4,726
Available-for-sale Securities, Gross Unrealized Loss, Accumulated in Investments	51	402
Available-for-sale Securities, Equity Securities	63,295	$ 28,398
Asset-backed Securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	14,902
Available-for-sale Equity Securities, Accumulated Gross Unrealized Gain, before Tax	23
Available-for-sale Securities, Gross Unrealized Loss, Accumulated in Investments	20
Available-for-sale Securities, Debt Securities	$ 14,905

This item represents the cost of debt securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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