CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:
Net income	$ 727,465	$ 547,241	$ 46,305
Adjustments to reconcile net income to net cash provided by operating activities:
Net realized investment gains	(75,564)	(127,469)	(121,439)
Net realized and unrealized gains of other investments	(128,814)	(87,623)	(31,013)
Amortization of fixed maturities	139,667	135,297	93,356
Other amortization and depreciation	23,272	13,821	16,905
Share-based compensation expense	57,168	67,912	39,134
Changes in:
Accrued interest receivable	88	1,126	(1,982)
Reinsurance recoverable balances	(66,169)	(93,490)	(192,782)
Deferred acquisition costs	(66,874)	18,279	(48,227)
Prepaid reinsurance premiums	(14,585)	(77,053)	(17,227)
Reserve for loss and loss expenses	523,409	633,686	1,392,670
Unearned premiums	229,157	230	120,786
Insurance and reinsurance balances, net	(250,463)	3,218	(28,562)
Other items	(789)	85,442	(77,782)
Net cash provided by operating activities	1,096,968	1,120,617	1,190,142
Cash flows from investing activities:
Fixed maturities	(12,230,274)	(13,513,143)	(15,472,001)
Equity securities	(240,926)	(377,749)	(603,746)
Other investments	(166,835)	(110,084)	(220,000)
Short-term investments	(198,168)	(383,981)	(841,124)
Proceeds from the sale of:
Fixed maturities	10,261,256	11,144,351	13,754,436
Equity securities	323,423	468,473	222,506
Other investments	93,277	53,590	70,988
Short-term investments	197,690	354,924	710,178
Proceeds from redemption of fixed maturities	1,407,676	1,456,553	1,422,171
Proceeds from redemption of short-term investments	61,715	69,751	151,216
Purchase of other assets	(24,304)	(35,322)	(42,193)
Change in restricted cash and cash equivalents	26,183	10,256	14,851
Net cash used in investing activities	(489,287)	(862,381)	(832,718)
Cash flows from financing activities:
Net proceeds from issuance of preferred shares	218,449	393,544	0
Repurchase of preferred shares	(100,000)	(404,073)	0
Repurchase of common shares	(472,263)	(317,687)	(65,885)
Dividends paid - common shares	(118,426)	(120,487)	(206,455)
Dividends paid - preferred shares	(39,193)	(38,228)	(36,875)
Proceeds from issuance of common shares	20,339	5,120	6,735
Sale of shares to noncontrolling interests	50,000	0	0
Net cash used in financing activities	(441,094)	(481,811)	(302,480)
Effect of exchange rate changes on foreign currency cash and cash equivalents	(3,078)	1,543	(2,610)
Increase (decrease) in cash and cash equivalents	163,509	(222,032)	52,334
Cash and cash equivalents - beginning of period	759,817	981,849	929,515
Cash and cash equivalents - end of period	923,326	759,817	981,849
Supplemental disclosures of cash flow information
Income taxes paid	22,472	10,897	23,853
Interest paid	$ 58,125	$ 58,125	$ 58,125