Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011
CASH FROM (USED IN) OPERATING ACTIVITIES:
Net income to common stockholders	$ 345,103	$ 274,184
Adjustments to reconcile net income to net cash from operating activities:
Net investment gains	(94,003)	(73,412)
Depreciation and amortization	65,089	57,332
Noncontrolling interests	41	(98)
Investment funds	(50,124)	(11,236)
Stock incentive plans	21,070	19,727
Change in:
Arbitrage trading account	(2,355)	(2,840)
Premiums and fees receivable	(192,803)	(111,411)
Reinsurance accounts	(90,587)	(137,192)
Deferred policy acquisition costs	(34,843)	(41,635)
Deferred income taxes	(195)	25,934
Reserves for losses and loss expenses	215,993	250,393
Unearned premiums	284,908	264,681
Other liabilities	(13,945)	(29,184)
Net cash from (used in) operating activities	453,349	485,243
CASH FROM (USED IN) INVESTING ACTIVITIES:
Proceeds from sale of fixed matuirty securities	549,876	1,129,377
Proceeds from sale of equity securities	233,239	112,760
Distributions from (contributions to) investment funds	(6,293)	(148,537)
Proceeds from maturities and prepayments of fixed maturity securities	1,659,751	1,190,751
Purchase of fixed maturity securities	(2,510,322)	(2,118,556)
Purchase of equity securities	(218,490)	(49,932)
Real estate purchased	(71,348)	(347,602)
Change in loans receivable	(106,721)	71,803
Net additions to real estate, furniture and equipment	(22,319)	(37,405)
Change in balances due to security brokers	79,344	122,447
Payment for business purchased, net of cash acquired	0	(8,579)
Net cash from (used in) investing activities	(413,283)	(83,473)
CASH FROM (USED IN) FINANCING ACTIVITIES:
Net proceeds from issuance of debt	375,641	309
Net proceeds from stock options exercised	8,667	13,757
Cash dividends to common stockholders	(35,730)	(32,272)
Purchase of common treasury shares	(121,362)	(177,648)
Other, net	15,799	16,816
Net cash from (used in) financing activities	243,015	(179,038)
Net impact on cash due to change in foreign exchange rates	(5,259)	446
Net change in cash and cash equivalents	277,822	223,178
Cash and cash equivalents at beginning of year	911,742	642,952
Cash and cash equivalents at end of period	$ 1,189,564	$ 866,130

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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).