UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows provided by (used in) operating activities:
Net income (loss)	$ 213,849	$ 83,028
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Total net realized (gains) losses on investments and net unrealized (gains) losses on investments, Trading - Life Funds Withheld Assets	(37,286)	(92,750)
Net realized and unrealized (gains) losses on derivative instruments	7,069	3,622
Amortization of premiums (discounts) on fixed maturities	42,178	47,505
(Income) loss from investment and operating affiliates	(28,921)	19,797
Share-based compensation	12,694	20,707
Depreciation and amortization	19,429	22,592
Accretion of deposit liabilities	11,430	12,055
Changes in:
Unpaid losses and loss expenses	290,788	330,160
Future policy benefit reserves	(55,634)	(59,858)
Funds withheld on GreyCastle life retrocession arrangements, net	(107,596)	(121,272)
Unearned premiums	1,222,570	1,148,149
Premiums receivable	(1,152,760)	(1,322,085)
Unpaid losses and loss expenses recoverable	(153,063)	(82,729)
Ceded unearned premiums	(797,191)	(436,332)
Reinsurance balances receivable	(59,052)	(49,781)
Deferred acquisition costs and value of business acquired	(205,830)	(156,373)
Reinsurance balances payable	849,492	460,982
Deferred tax asset - net	10,852	(7,945)
Derivatives	58,104	17,863
Other assets	(100,791)	(47,084)
Other liabilities	(128,606)	(128,752)
Other	(9,323)	(41,618)
Total adjustments	(261,346)	(227,067)
Net cash provided by (used in) operating activities	(47,497)	(144,039)
Cash flows provided by (used in) investing activities:
Proceeds from sale of fixed maturities and short-term investments	2,492,005	3,772,077
Proceeds from redemption of fixed maturities and short-term investments	1,228,356	949,221
Proceeds from sale of equity securities	46,379	62,895
Purchases of fixed maturities and short term investments	(3,633,007)	(4,325,679)
Purchases of equity securities	(47,967)	(55,411)
Proceeds from sale of affiliates	168,237	41,538
Purchases of affiliates	(35,926)	(247,049)
Purchase of subsidiaries, net of cash acquired	0	(69,745)
Change in restricted cash	(7,019)	(6,027)
Other, net	23,429	82,141
Net cash provided by (used in) investing activities	234,487	203,961
Cash flows provided by (used in) financing activities:
Proceeds from issuance of ordinary shares and exercise of stock options	23,296	491
Buybacks of common shares	(200,488)	(355,901)
Employee withholding on share-based compensation	(22,871)	(27,074)
Dividends paid on common shares	(58,392)	(57,861)
Distributions to non-controlling interests	(25,400)	(27,857)
Contributions from non-controlling interests	26	883
Deposit liabilities	(7,771)	(8,546)
Net cash provided by (used in) financing activities	(291,600)	(475,865)
Effects of exchange rate changes on foreign currency cash	30,273	(19,396)
Increase (decrease) in cash and cash equivalents	(74,337)	(435,339)
Cash and cash equivalents beginning of period	3,426,988	3,256,236
Cash and cash equivalents end of period	3,352,651	2,820,897
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	$ 50,101	$ 236,080