CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows provided by (used in) operating activities:
Net income (loss)	$ (490,137)	$ 570,145	$ 1,313,339
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Net realized (gains) losses on investments	(221,876)	(372,138)	(202,178)
Net realized and unrealized (gains) losses on derivative instruments	41,732	(2,521)	(53,123)
Amortization of premiums (discounts) on fixed maturities	160,191	193,482	194,824
(Income) loss from investment and operating affiliates	(122,487)	(67,802)	(46,072)
Loss (gain) sale of subsidiaries	0	(7,088)	0
Gain on sale of operating affiliate	0	0	(340,407)
Share based compensation	64,199	81,001	74,431
Depreciation and amortization	97,038	118,063	92,313
Accretion of deposit liabilities	29,243	43,984	43,633
Changes in:
Unpaid losses and loss expenses	2,881,359	1,073,313	(211,831)
Future policy benefit reserves	(235,328)	(162,096)	(278,818)
Funds withheld on life retrocession agreements, net	(281,136)	(223,516)	(210,943)
Unearned premiums	733,182	436,106	(528,214)
Premiums receivable	(1,200,673)	(1,084,432)	156,168
Unpaid losses and loss expenses recoverable	(1,575,247)	(360,223)	(439,548)
Ceded unearned premiums	(430,213)	70,529	237,017
Reinsurance balances receivable	(327,462)	(174,126)	2,319
Deferred acquisition costs and value of business acquired	(118,566)	(62,926)	126,455
Reinsurance balances payable	1,120,507	398,738	229,205
Deferred tax asset - net	(59,498)	(41,641)	(47,924)
Derivatives	(18,856)	119,038	185,300
Other assets	(54,417)	(26,673)	17,054
Other liabilities	(236,443)	(49,853)	152,822
Other	72,192	(65,548)	26,968
Total adjustments	523,456	373,761	(668,858)
Net cash provided by (used in) operating activities	33,319	943,906	644,481
Cash flows provided by (used in) investing activities:
Proceeds from sale of fixed maturities and short-term investments	15,702,126	12,757,580	16,868,228
Proceeds from redemption of fixed maturities and short-term investments	3,470,496	3,847,709	3,751,174
Proceeds from sale of equity securities	757,549	848,779	664,735
Purchases of fixed maturities and short term investments	(19,281,797)	(15,457,689)	(19,718,064)
Purchases of equity securities	(326,610)	(1,103,447)	(567,334)
Proceeds from sale of affiliates	593,539	397,091	748,575
Purchases of affiliates	(176,034)	(681,385)	(280,856)
Purchase of subsidiaries, net of acquired cash	0	(92,893)	(1,020,015)
Proceeds from sale of subsidiary	0	22,998	0
Change in restricted cash	(3,993)	1,488	(154,992)
Other, net	(72,550)	197,536	(155,019)
Net cash provided by (used in) investing activities	662,726	737,767	136,432
Cash flows provided by (used in) financing activities:
Proceeds from issuance of ordinary shares and exercise of stock options	50,634	9,854	9,976
Buybacks of ordinary shares	(571,614)	(1,051,050)	(468,971)
Repurchase of preference shares	(411,492)	0	0
Employee withholding on share-based compensation	(24,189)	(28,569)	(28,925)
Dividends paid on ordinary shares	(228,232)	(222,761)	(208,516)
Distributions to non-controlling interests	(124,305)	(130,447)	(117,683)
Contributions from non-controlling interest	59,583	47,524	23,610
Proceeds from issuance of debt	558,311	0	980,600
Repayment of debt	(17,909)	(8,248)	(87,447)
Deposit liabilities	(34,565)	(69,482)	(84,758)
Net cash provided by (used in) financing activities	(743,778)	(1,453,179)	17,886
Effects of exchange rate changes on foreign currency cash	56,699	(57,742)	(64,377)
Increase (decrease) in cash and cash equivalents	8,966	170,752	734,422
Cash and cash equivalents – beginning of period	3,426,988	3,256,236	2,521,814
Cash and cash equivalents – end of period	3,435,954	3,426,988	3,256,236
Supplemental cash flow disclosures:
Net taxes paid	30,955	81,662	96,886
Interest paid on notes payable and debt	137,584	138,025	115,598
Life Funds Withheld Assets
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Net realized and unrealized (gains) losses on derivative instruments	$ 206,015	$ 540,090	$ 151,691