Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Mar. 31, 2011	Jun. 30, 2012
CASH FROM (USED IN) OPERATING ACTIVITIES:
Net income to common stockholders	$ 197,774	$ 244,156
Adjustments to reconcile net income to net cash from operating activities:
Net investment gains	(52,174)	(71,777)
Depreciation and amortization	33,179	47,147
Noncontrolling interests	(59)	(20)
Investment funds	(25,218)	(63,243)
Stock incentive plans	13,026	15,827
Change in:
Arbitrage trading account	(4,319)	(1,535)
Premiums and fees receivable	(148,144)	(139,183)
Reinsurance accounts	(71,887)	(46,182)
Deferred policy acquisition costs	(30,255)	(21,637)
Deferred income taxes	21,037	(4,244)
Reserves for losses and loss expenses	163,604	151,975
Unearned premiums	203,515	188,902
Other liabilities	(83,687)	12,225
Net cash from (used in) operating activities	216,392	312,411
CASH FROM (USED IN) INVESTING ACTIVITIES:
Proceeds from sale of fixed matuirty securities	707,598	370,902
Proceeds from sale of equity securities	100,837	70,274
Distributions from (contributions to) investment funds	(124,201)	23,090
Proceeds from maturities and prepayments of fixed maturity securities	774,127	922,961
Purchase of fixed maturity securities	(1,419,857)	(1,658,418)
Purchase of equity securities	(44,736)	(184,751)
Real estate purchased	(117,893)	(15,475)
Change in loans receivable	43,700	(61,886)
Net additions to real estate, furniture and equipment	(18,679)	(20,376)
Change in balances due to security brokers	73,311	38,700
Payment for business purchased, net of cash acquired	(8,579)	0
Net cash from (used in) investing activities	(34,372)	(514,979)
CASH FROM (USED IN) FINANCING ACTIVITIES:
Net proceeds from issuance of debt	0	364,044
Net proceeds from stock options exercised	13,217	4,776
Repayment of debt	624	0
Cash dividends to common stockholders	(21,273)	(11,042)
Purchase of common treasury shares	(59,159)	(48,346)
Other, net	22,635	19,500
Net cash from (used in) financing activities	(43,956)	328,932
Net impact on cash due to change in foreign exchange rates	13,865	(25,886)
Net change in cash and cash equivalents	151,929	100,478
Cash and cash equivalents at beginning of year	642,952	911,742
Cash and cash equivalents at end of period		$ 1,012,220

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Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits are not generally reported as cash and cash equivalents. Includes cash and cash equivalents associated with the entity's continuing operations. Excludes cash and cash equivalents associated with the disposal group (and discontinued operation).