Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
CASH FROM OPERATING ACTIVITIES:
Net (loss) income to common stockholders	$ (4,418)	$ 180,722
Adjustments to reconcile net income to net cash from (used in) operating activities:
Net investment losses (gains)	177,174	(68,653)
Depreciation and amortization	25,063	27,424
Noncontrolling interests	892	892
Investment funds	(40,576)	(11,411)
Stock incentive plans	11,683	14,828
Change in:
Arbitrage trading account	2,455	(7,753)
Premiums and fees receivable	(97,169)	(156,450)
Reinsurance accounts	(43,104)	(20,272)
Deferred policy acquisition costs	(26,139)	(17,732)
Income taxes	(12,500)	36,180
Reserves for losses and loss expenses	200,294	119,780
Unearned premiums	163,793	135,184
Other	(204,878)	(154,409)
Net cash from operating activities	152,570	78,330
CASH FROM INVESTING ACTIVITIES:
Proceeds from sale of fixed maturity securities	1,574,232	973,626
Proceeds from sale of equity securities	5,311	37,762
Distributions from (contributions to) investment funds	99,194	(13,874)
Proceeds from maturities and prepayments of fixed maturity securities	1,055,722	686,795
Purchase of fixed maturity securities	(2,598,076)	(1,528,267)
Purchase of equity securities	(35,260)	(35,314)
Real estate purchased	(24,249)	(52,901)
Change in loans receivable	2,877	(726)
Net purchases of property, furniture and equipment	(14,637)	(3,299)
Change in balances due to security brokers	(34,378)	(22,011)
Other	86	0
Net cash from investing activities	30,822	41,791
CASH USED IN FINANCING ACTIVITIES:
Net payments for stock options exercised	(3,321)	0
Net proceeds from issuance of debt	4,259	0
Cash dividends to common stockholders	(20,069)	0
Purchase of common treasury shares	(202,621)	0
Other, net	(204)	(976)
Net cash used in financing activities	(221,956)	(976)
Net impact on cash due to change in foreign exchange rates	(20,134)	681
Net change in cash and cash equivalents	(58,698)	119,826
Cash and cash equivalents at beginning of year	1,023,710	817,602
Cash and cash equivalents at end of period	$ 965,012	$ 937,428