Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Condensed Consolidated Balance Sheets
Available-for-sale, amortized cost	$ 1,512,806	$ 1,518,156
Equity securities available-for-sale, cost	207,302	202,437
Premiums and reinsurance balances receivable, allowances for uncollectible amounts	15,168	14,898
Reinsurance balances recoverable on unpaid losses and settlement expenses, allowances for uncollectible amounts	11,497	11,885
Property and equipment, accumulated depreciation	$ 39,910	$ 38,447
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	66,601,890	66,474,342
Common stock, shares outstanding (in shares)	43,671,676	43,544,128
Treasury stock, shares (in shares)	22,930,214	22,930,214