Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Summarized financial information for these segments
Insurance premiums and contract charges earned	$ 179,739	$ 175,403
Net investment income	83,313us-gaap_NetInvestmentIncome	83,044us-gaap_NetInvestmentIncome
Net income (loss)	34,275us-gaap_NetIncomeLoss	28,366us-gaap_NetIncomeLoss
Assets	10,074,419us-gaap_Assets		9,768,527us-gaap_Assets
Property and casualty [Member]
Summarized financial information for these segments
Insurance premiums and contract charges earned	146,749	143,892
Net investment income	9,433	9,285
Net income (loss)	17,623	14,027
Assets	1,144,361		1,107,962
Annuity [Member]
Summarized financial information for these segments
Insurance premiums and contract charges earned	6,223	5,924
Net investment income	56,392	55,857
Net income (loss)	12,510	12,239
Assets	6,898,018		6,683,473
Life [Member]
Summarized financial information for these segments
Insurance premiums and contract charges earned	26,767	25,587
Net investment income	17,708	18,134
Net income (loss)	3,385	3,882
Assets	1,918,822		1,858,150
Corporate and other [Member]
Summarized financial information for these segments
Net investment income	6	2
Net income (loss)	757	(1,782)
Assets	140,578		155,678
Intersegment eliminations [Member]
Summarized financial information for these segments
Net investment income	(226)	(234)
Assets	$ (27,360)		$ (36,736)

The sum of insurance premiums earned, premiums earned on the income statement for all insurance contracts after subtracting any amounts ceded to another insurer and adding premiums assumed from other insurers, plus contract charges earned on investment and universal life-type contracts.

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Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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