Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
CASH FROM OPERATING ACTIVITIES:
Net income to common stockholders	$ 397,431	$ 346,472
Adjustments to reconcile net income to net cash from (used in) operating activities:
Net realized and unrealized gains on investments	(142,226)	(118,095)
Depreciation and amortization	51,289	56,372
Noncontrolling interests	1,610	1,879
Investment funds	(58,251)	(53,070)
Stock incentive plans	27,340	19,722
Change in:
Arbitrage trading account	(14,797)	(7,871)
Premiums and fees receivable	(223,771)	(152,832)
Reinsurance accounts	(112,681)	(77,140)
Deferred policy acquisition costs	(23,632)	(11,152)
Income taxes	2,759	(39,069)
Reserves for losses and loss expenses	350,981	123,582
Unearned premiums	254,010	171,468
Other	(107,416)	(140,904)
Net cash from operating activities	402,646	119,362
CASH FROM (USED IN) INVESTING ACTIVITIES:
Proceeds from sale of fixed maturity securities	1,320,079	2,773,554
Proceeds from sale of equity securities	39,103	284,204
Contributions to investment funds	(2,896)	(4,996)
Proceeds from maturities and prepayments of fixed maturity securities	1,490,772	1,305,805
Purchase of fixed maturity securities	(2,633,251)	(4,062,901)
Purchase of equity securities	(41,849)	(87,059)
Real estate purchased	(117,773)	(419,021)
Change in loans receivable	140	(16,310)
Net additions to property, furniture and equipment	(10,804)	(29,704)
Change in balances due to security brokers	19,096	46,641
Payment for business purchased net of cash acquired	0	6,637
Net cash from (used in) investing activities	62,617	(216,424)
CASH (USED IN) FROM FINANCING ACTIVITIES:
Repayment of senior notes and other debt	0	(23)
Net proceeds from issuance of debt	0	200,838
Cash dividends to common stockholders	(18,302)	(77,873)
Purchase of common treasury shares	0	(6,799)
Other, net	(5,548)	(1,763)
Net cash (used in) from financing activities	(23,850)	114,380
Net impact on cash due to change in foreign exchange rates	(841)	(56,587)
Net change in cash and cash equivalents	440,572	(39,269)
Cash and cash equivalents at beginning of year	817,602	950,471
Cash and cash equivalents at end of period	$ 1,258,174	$ 911,202