Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities
Net earnings	$ 168,893	$ 238,063
Adjustments to reconcile net earnings to net cash provided by (used in) operating activities:
Depreciation and amortization	45,109	43,554
Change in the fair value of equity securities	138,777	(112,728)
Net realized capital (gains) losses	10,003	(12,931)
Change in allowance for credit losses on available for sale securities	582	(1,972)
(Increase) decrease in reinsurance recoverables, net of reinsurance payable	69,339	(6,669)
(Increase) decrease in premium balances receivable	(69,795)	(138,822)
(Increase) decrease in ceded unearned premiums	(19,676)	(34,049)
(Increase) decrease in deferred acquisition costs	(49,901)	(41,969)
(Increase) decrease in funds held under reinsurance agreements	128,177	8,951
Increase (decrease) in unearned premiums	206,882	192,735
Increase (decrease) in loss and loss adjustment expenses	(41,268)	322,420
Change in unrealized foreign currency exchange rate losses (gains)	34,879	44,344
Other, net	(111,098)	(58,632)
Net adjustments	342,010	204,232
Net cash provided by operating activities	510,903	442,295
Cash flows from investing activities
Purchases of debt securities	(1,527,777)	(1,401,010)
Purchases of equity securities	(147,826)	(746,350)
Sales of debt securities	778,330	1,197,630
Maturities and redemptions of debt securities	426,106	552,933
Sales of equity securities	276,605	262,690
Net (purchases) sales of short-term investments	(163,620)	117,295
Net (purchases) sales and maturities of commercial mortgage loans	13,304	30,618
(Purchases) sales of property and equipment	(14,249)	(12,322)
Purchases of affiliates and subsidiaries, net of cash acquired	0	0
Other, net	56,101	101,159
Net cash (used in) provided by investing activities	(303,026)	102,643
Cash flows from financing activities
Treasury stock acquisitions	(95,987)	(63,192)
Increase (decrease) in other debt	(24,820)	(55,729)
Other, net	(13,992)	(8,938)
Net cash used in financing activities	(134,799)	(127,859)
Effect of foreign exchange rate changes on cash	(7,988)	(11,047)
Net increase in cash	65,090	406,032
Cash at beginning of period	927,966	791,442
Cash at end of period	993,056	1,197,474
Supplemental disclosures of cash flow information
Interest paid	19,243	10,000
Income taxes paid	$ 13,766	$ 22,599