Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Cash Provided by (Used in) Operating Activities	$ 498,756	$ 506,805
Cash Flows from Investing Activities:
Proceeds from Sales of Fixed-Maturity Investments Available for sale	894,998	770,393
Proceeds from Sales of Trading Securities	11,602	120,875
Proceeds from Sales of Equity Securities	77,445	52,295
Proceeds from Redemption of Fixed-Maturity Investments Available for sale	443,723	287,557
Proceeds from Redemptions of Trading securities	22,112	36,827
Purchases of Fixed-Maturity Investments Available for sale	(2,099,281)	(1,352,883)
Purchases of Equity Securities	(69,206)	(45,748)
Sales, Redemptions and (Purchases) of Short-term Investments, Net	(21,797)	(12,199)
Sales, Redemptions and (Purchases) of Other assets and other invested assets, net	989	687
Proceeds from sale of a subsidiary, net of cash sold	16,481	0
Purchases of property and equipment, net	(14,723)	(20,707)
Net cash provided by (used in) investing activities	(737,657)	(162,903)
Cash Flows from Financing Activities:
Dividends and dividend equivalents paid	(73,365)	(1,559)
Issuance of senior notes, net	515,567	442,498
Repayments and repurchases of senior notes	0	(610,739)
Issuance of common stock	1,505	2,126
Repurchases of common shares	(226,305)	(275,185)
Credit facility commitment fees paid	(1,993)	(710)
Change in secured borrowings, net (with terms three months or less)	(19,191)	9,568
Proceeds from secured borrowings (with terms greater than 3 months)	138,909	73,011
Payments of secured borrowings (with terms greater than 3 months)	(105,977)	(37,550)
Repayments of other borrowings	(79)	(114)
Net cash provided by (used in) financing activities	229,071	(398,654)
Effect of exchange rate changes on cash and restricted cash	0	(4)
Increase (decrease) in cash and restricted cash	(9,830)	(54,756)
Cash and restricted cash, beginning of period	96,274	107,002
Cash and restricted cash, end of period	$ 86,444	$ 52,246

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