Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Condensed Consolidated Balance Sheets
Available-for-sale, amortized cost	$ 1,956,137	$ 1,915,278
Available-for-sale, allowance for credit losses	985	0
Equity securities, cost	270,987	262,131
Premiums and reinsurance balances receivable, allowances for uncollectible amounts	17,139	16,682
Reinsurance balances recoverable on unpaid losses and settlement expenses, allowances for uncollectible amounts	8,035	9,402
Property and equipment, accumulated depreciation	$ 65,762	$ 62,703
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	200,000,000	100,000,000
Common stock, shares issued (in shares)	67,882,816	67,799,229
Common stock, shares outstanding (in shares)	44,952,602	44,869,015
Treasury stock, shares (in shares)	22,930,214	22,930,214