Unaudited Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Investments:
Fixed maturities available for sale, at fair value (amortized cost: $17,955,515 and $16,598,808; net of allowance for credit losses: $3,933 at September 30, 2020)	$ 18,452,888	$ 16,894,526
Short-term investments available for sale, at fair value (amortized cost: $2,038,244 and $957,283; net of allowance for credit losses: $0 at September 30, 2020)	2,039,097	956,546
Collateral received under securities lending, at fair value (amortized cost: $64,251 and $388,366)	64,259	388,376
Equity securities, at fair value	1,502,015	838,925
Investments accounted for using the fair value option	3,749,575	3,663,477
Investments accounted for using the equity method	1,883,702	1,660,396
Total investments	27,691,536	24,402,246
Cash	976,398	726,230
Accrued investment income	106,940	117,937
Securities pledged under securities lending, at fair value (amortized cost: $62,662 and $378,738)	62,749	379,868
Premiums receivable (net of allowance for credit losses: $37,100 and $21,003)	2,225,311	1,778,717
Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses (net of allowance for credit losses: $13,994 and $1,364)	4,621,937	4,346,816
Contractholder receivables (net of allowance for credit losses: $5,902 and $0)	2,185,614	2,119,460
Ceded unearned premiums	1,450,200	1,234,683
Deferred acquisition costs	750,901	633,400
Receivable for securities sold	158,674	24,133
Goodwill and intangible assets	713,777	738,083
Other assets	1,771,998	1,383,788
Total assets	42,716,035	37,885,361
Liabilities
Reserve for losses and loss adjustment expenses	15,900,526	13,891,842
Unearned premiums	5,062,052	4,339,549
Reinsurance balances payable	873,067	667,072
Contractholder payables	2,191,515	2,119,460
Collateral held for insured obligations	221,957	206,698
Senior notes	2,860,811	1,871,626
Revolving credit agreement borrowings	210,687	484,287
Securities lending payable	64,251	388,366
Payable for securities purchased	382,236	87,579
Other liabilities	1,681,181	1,513,330
Total liabilities	29,448,283	25,569,809
Commitments and Contingencies
Redeemable noncontrolling interests	57,835	55,404
Shareholders' Equity
Non-cumulative preferred shares	780,000	780,000
Common shares ($0.0011 par, shares issued: 578,024,671 and 574,617,195)	642	638
Additional paid-in capital	1,950,782	1,889,683
Retained earnings	11,829,322	11,021,006
Accumulated other comprehensive income (loss), net of deferred income tax	386,357	212,091
Common shares held in treasury, at cost (shares: 172,005,713 and 168,997,994)	(2,495,106)	(2,406,047)
Total shareholders' equity available to Arch	12,451,997	11,497,371
Non-redeemable noncontrolling interests	757,920	762,777
Total shareholders' equity	13,209,917	12,260,148
Total liabilities, noncontrolling interests and shareholders' equity	$ 42,716,035	$ 37,885,361