Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Condensed Consolidated Balance Sheets
Available-for-sale, amortized cost	$ 1,912,851	$ 1,915,278
Available-for-sale, allowance for credit losses	878	0
Equity securities, cost	272,152	262,131
Premiums and reinsurance balances receivable, allowances for uncollectible amounts	16,948	16,682
Reinsurance balances recoverable on unpaid losses and settlement expenses, allowances for uncollectible amounts	8,539	9,402
Property and equipment, accumulated depreciation	$ 64,322	$ 62,703
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	67,852,870	67,799,229
Common stock, shares outstanding (in shares)	44,922,656	44,869,015
Treasury stock, shares (in shares)	22,930,214	22,930,214