Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt securities, available-for-sale	$ 4,382,254	$ 4,476,358
Short-term investments	70,761	67,353
Cash and cash equivalents	309,802	135,942
Other investments	287,683	311,287
Restricted cash and cash equivalents	30,070	28,521
Accrued investment income	26,131	30,927
Premiums and other receivables, net	1,541,760	1,428,948
Deferred acquisition costs	277,368	263,523
Reinsurance recoverable, net	1,401,681	1,394,308
Prepaid reinsurance premiums	511,648	575,747
Premises and equipment, net	398,161	403,827
Intangible assets, net	357,568	365,823
Prepaid and other assets	86,359	94,642
Unpaid loss and loss adjustment expense reserves	2,848,193	2,886,414
Unearned premiums and other revenue	2,376,375	2,312,241
Reinsurance payable	553,982	562,844
Accounts payable and accrued expenses	313,638	315,366
Other liabilities	$ 411,820	$ 376,169
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	113,708,996	113,368,811
Common stock, shares outstanding	113,708,996	113,368,811
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Shares of preferred stock issued	2,565,120	2,565,120
Preferred stock, shares outstanding	2,565,120	2,565,120
Aggregate liquidation preference	$ 450,000	$ 450,000
Debt securities, available-for sale, allowance for expected credit losses	2,927	0
Premiums and other receivables, allowance for expected credit losses	27,114	24,067
Reinsurance recoverable, allowance for expected credit losses	517	0
Reciprocal Exchanges
Debt securities, available-for-sale	313,743	324,249
Short-term investments	19,778	5,245
Cash and cash equivalents	0	959
Restricted cash and cash equivalents	116	24
Accrued investment income	2,152	2,001
Premiums and other receivables, net	49,344	55,859
Deferred acquisition costs	22,737	23,307
Reinsurance recoverable, net	119,508	119,125
Prepaid reinsurance premiums	91,003	105,894
Premises and equipment, net	93	241
Intangible assets, net	3,180	3,225
Prepaid and other assets	4,110	3,521
Unpaid loss and loss adjustment expense reserves	197,934	205,786
Unearned premiums and other revenue	232,538	252,553
Reinsurance payable	38,353	35,689
Accounts payable and accrued expenses	5,746	8,497
Other liabilities	41,266	30,803
Debt securities, available-for sale, allowance for expected credit losses	298
Premiums and other receivables, allowance for expected credit losses	1,013	541
Reinsurance recoverable, allowance for expected credit losses	173
Related Parties
Other investments	235,843	238,841
Accrued investment income	$ 1,203	$ 2,391