UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows provided by (used in) operating activities:
Net income (loss)	$ 161,233	$ 213,849
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Total realized investment (gains) losses	83,355	(37,286)
Net realized and unrealized (gains) losses on derivative instruments	(4,221)	7,069
Amortization of premiums (discounts) on fixed maturities	32,298	42,178
(Income) loss from investment and operating affiliates	(39,800)	(28,921)
Share-based compensation	15,448	12,694
Depreciation and amortization	22,481	19,429
Accretion of deposit liabilities	11,125	11,430
Changes in:
Unpaid losses and loss expenses	(240,207)	290,788
Future policy benefit reserves	(51,981)	(55,634)
Funds withheld on GreyCastle life retrocession arrangements, net	(24,578)	(107,596)
Unearned premiums	1,310,888	1,222,570
Premiums receivable	(979,464)	(1,152,760)
Unpaid losses and loss expenses recoverable	36,804	(153,063)
Ceded unearned premiums	(730,516)	(797,191)
Reinsurance balances receivable	(272,531)	(59,052)
Deferred acquisition costs and value of business acquired	(205,798)	(205,830)
Reinsurance balances payable	695,220	849,492
Deferred tax asset - net	25,190	10,852
Derivatives	8,162	58,104
Other assets	(42,006)	(100,791)
Other liabilities	(51,327)	(128,606)
Other	25,022	(9,323)
Total adjustments	(399,357)	(261,346)
Net cash provided by (used in) operating activities	(238,124)	(47,497)
Cash flows provided by (used in) investing activities:
Proceeds from sale of fixed maturities and short-term investments	4,369,199	2,492,005
Proceeds from redemption of fixed maturities and short-term investments	701,404	1,228,356
Proceeds from sale of equity securities	78,716	46,379
Purchases of fixed maturities and short term investments	(4,917,191)	(3,633,007)
Purchases of equity securities	(33,230)	(47,967)
Proceeds from sale of affiliates	244,340	168,237
Purchases of affiliates	(76,014)	(35,926)
Other, net	(26,782)	23,429
Net cash provided by (used in) investing activities	340,442	241,506
Cash flows provided by (used in) financing activities:
Proceeds from issuance of ordinary shares and exercise of stock options	46,504	23,296
Buybacks of common shares	(1,663)	(200,488)
Employee withholding on share-based compensation	(16,696)	(22,871)
Dividends paid on common shares	0	(58,392)
Distributions to non-controlling interests	(15,946)	(25,400)
Contributions from non-controlling interests	439	26
Contingent consideration paid on business combination	(5,000)	0
Deposit liabilities	(71,124)	(7,771)
Net cash provided by (used in) financing activities	(63,486)	(291,600)
Effects of exchange rate changes on foreign currency cash	7,503	30,273
Increase (decrease) in cash, cash equivalents and restricted cash	46,335	(67,318)
Cash, cash equivalents and restricted cash - beginning of year	3,593,451	3,580,492
Cash, cash equivalents and restricted cash - end of period	3,639,786	3,513,174
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	$ (22,921)	$ 50,101