Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Condensed Consolidated Balance Sheets
Available-for-sale, amortized cost	$ 1,518,156	$ 1,448,204
Equity securities available-for-sale, cost	202,437	193,535
Premiums and reinsurance balances receivable, allowances for uncollectible amounts	14,898	14,245
Reinsurance balances recoverable on unpaid losses and settlement expenses, allowances for uncollectible amounts	11,885	13,049
Property and equipment, accumulated depreciation	$ 38,447	$ 34,365
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)	66,474,342	66,032,929
Common stock, shares outstanding (in shares)	43,544,128	43,102,715
Treasury stock, shares (in shares)	22,930,214	22,930,214