Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities
Net earnings	$ 204,641	$ 196,294
Adjustments to reconcile net earnings to net cash provided by (used in) operating activities:
Depreciation and amortization	34,406	65,199
Net realized capital (gains) losses	(96,836)	(50,902)
Other than temporary impairment losses	5,220	32,312
(Increase) decrease in reinsurance recoverables, net of reinsurance payable	26,318	50,668
(Increase) decrease in premium balances receivable	(113,005)	(87,487)
(Increase) decrease in ceded unearned premiums	(12,011)	(14,029)
(Increase) decrease in deferred acquisition costs	(23,658)	(17,960)
Increase (decrease) in unearned premiums	92,398	18,338
Increase (decrease) in loss and loss adjustment expenses	(87,822)	(188,267)
Change in unrealized foreign exchange (losses) gains	(18,543)	78,955
Other, net	(126,845)	67,433
Net adjustments	(320,378)	(45,740)
Net cash provided by (used in) operating activities	(115,737)	150,554
Cash flows from investing activities
Purchases of debt securities	(1,744,739)	(1,903,342)
Purchases of equity securities	(704,290)	(1,376,991)
Sales of debt securities	1,668,560	2,178,552
Maturities and redemptions of debt securities	244,451	432,542
Sales of equity securities	314,160	863,175
Net (purchase) sale in short-term investments	418,649	(372,447)
Purchases of property and equipment	(12,019)	(1,557)
Other, net	(1,499)	20,439
Net cash (used in) provided by investing activities	183,273	(159,629)
Cash flows from financing activities
Treasury stock acquisitions	(94,642)	(31,576)
Other, net	8,929	(8,735)
Net cash provided by (used in) financing activities	(85,713)	(40,311)
Effect of exchange rate changes on cash	1,276	(25,259)
Net (decrease) increase in cash	(16,901)	(74,645)
Cash at beginning of period	498,315	649,524
Cash at end of period	481,414	574,879
Cash paid during the period for:
Interest paid	8,580	8,438
Income taxes paid (refunds received)	$ 71,106	$ (45,366)