Unaudited Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Operating Activities
Net income (loss)	$ 601,377	$ 1,194,372
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Net realized (gains) losses	555,273	(379,049)
Equity in net (income) or loss of investment funds accounted for using the equity method and other income or loss	43,815	(181,028)
Amortization of intangible assets	54,374	29,688
Share-based compensation	66,518	57,564
Changes in:
Reserve for losses and loss adjustment expenses, net of unpaid losses and loss adjustment expenses recoverable	634,482	948,505
Unearned premiums, net of ceded unearned premiums	872,371	838,650
Premiums receivable	(1,085,790)	(781,391)
Deferred acquisition costs	(173,911)	(214,893)
Reinsurance balances payable	72,095	331,461
Other items, net	(186,636)	(231,307)
Net cash provided by (used for) operating activities	1,453,968	1,612,572
Investing Activities
Purchases of fixed maturity investments	(9,705,957)	(23,554,384)
Purchases of equity securities	(655,573)	(620,774)
Purchases of other investments	(920,384)	(1,033,134)
Proceeds from sales of fixed maturity investments	8,078,968	23,130,388
Proceeds from sales of equity securities	1,490,212	542,290
Proceeds from sales, redemptions and maturities of other investments	863,333	772,549
Proceeds from redemptions and maturities of fixed maturity investments	444,073	805,836
Net settlements of derivative instruments	(44,838)	17,286
Net (purchases) sales of short-term investments	(439,992)	(378,086)
Change in cash collateral related to securities lending	0	(826)
Purchase of operating affiliate	0	(546,349)
Purchases of fixed assets	(23,830)	(23,585)
Other	98,386	(204,889)
Net cash provided by (used for) investing activities	(815,602)	(1,093,678)
Financing Activities
Proceeds from issuance of preferred shares, net	0	485,821
Purchases of common shares under share repurchase program	(575,676)	(485,315)
Proceeds from common shares issued, net	(4,065)	185
Change in cash collateral related to securities lending	0	826
Third party investment in non-redeemable noncontrolling interests	0	15,971
Dividends paid to redeemable noncontrolling interests	0	(1,907)
Other	(82,007)	27,639
Preferred dividends paid	(20,368)	(20,805)
Net cash provided by (used for) financing activities	(682,116)	22,415
Effects of exchange rate changes on foreign currency cash and restricted cash	(42,790)	(13,390)
Increase (decrease) in cash and restricted cash	(86,540)	527,919
Cash and restricted cash, beginning of year	1,314,771	1,290,544
Cash and restricted cash, end of period	$ 1,228,231	$ 1,818,463