CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net income (loss)	$ 358,770	$ (57,783)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Net investment (gains) losses	(102,936)	9,831
Net realized and unrealized (gains) losses on other investments	(83,247)	39,700
Amortization of fixed maturities	19,054	14,850
Interest in (income) loss of equity method investments	(18,960)	16,475
Amortization of value of business acquired	2,056	3,083
Other amortization and depreciation	31,346	30,481
Share-based compensation expense, net of cash payments	13,950	7,125
Changes in:
Accrued interest receivable	1,760	9,223
Reinsurance recoverable balances on unpaid and paid losses	(161,894)	(353,946)
Deferred acquisition costs	(144,256)	(92,026)
Prepaid reinsurance premiums	(284,411)	(250,988)
Reserve for losses and loss expenses	229,099	438,746
Unearned premiums	1,014,854	797,402
Insurance and reinsurance balances, net	(338,258)	(440,688)
Other items	(2,000)	(65,493)
Net cash provided by operating activities	534,927	105,992
Purchases of:
Fixed maturities, available for sale	(7,528,567)	(5,311,263)
Fixed maturities, held to maturity	(117,175)	0
Equity securities	(66,443)	(15,724)
Mortgage loans	(73,472)	(95,764)
Other investments	(125,534)	(75,803)
Short-term investments	(116,599)	(134,822)
Proceeds from the sale of:
Fixed maturities, available for sale	6,255,928	5,357,595
Equity securities	10,876	86,833
Other investments	172,499	80,235
Short-term investments	124,271	81,215
Proceeds from the redemption of fixed maturities, available for sale	960,936	796,594
Proceeds from the redemption of fixed maturities, held to maturity	118,897	0
Proceeds from redemption of short-term investments	40,868	57,948
Proceeds from the repayment of mortgage loans	10,940	3,951
Purchase of other assets	(14,107)	(28,470)
Net cash provided by (used in) investing activities	(346,682)	802,525
Cash flows from financing activities:
Taxes paid on withholding shares	(9,820)	(8,602)
Dividends paid - common shares	(74,306)	(71,994)
Repurchase of preferred shares	0	(225,000)
Dividends paid - preferred shares	(15,125)	(16,706)
Redemption of senior notes	0	(500,000)
Net cash used in financing activities	(99,251)	(822,302)
Effect of exchange rate changes on foreign currency cash, cash equivalents and restricted cash	(2,783)	(13,839)
Increase in cash, cash equivalents and restricted cash	86,211	72,376
Cash, cash equivalents and restricted cash - beginning of period	1,503,232	1,576,457
Cash, cash equivalents and restricted cash - end of period	1,589,443	1,648,833
Supplemental disclosures of cash flow information:
Income taxes paid (refund)	29,849	(408)
Interest paid	$ 29,700	$ 34,820