Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
CASH FROM OPERATING ACTIVITIES:
Net income to common stockholders	$ 394,803	$ 449,287	$ 309,057
Adjustments to reconcile net income to net cash from operating activities:
Net investment (gains) losses	(125,481)	(56,581)	38,408
Depreciation and amortization	88,012	82,867	78,875
Noncontrolling interests	(70)	279	23
Investment funds	1,751	49,400	166,685
Stock incentive plans	27,175	27,407	24,465
Change in:
Arbitrage trading account	(8,106)	(12,993)	(406,622)
Premiums and fees receivable	(122,468)	(41,167)	17,159
Reinsurance accounts	(161,070)	(14,960)	26,010
Deferred policy acquisition costs	(43,738)	(15,272)	6,181
Deferred income taxes	44,945	63,866	(52,536)
Reserves for losses and loss expenses	325,758	(103,745)	41,923
Unearned premiums	238,499	3,414	(57,261)
Other	10,269	19,514	123,687
Net cash from operating activities	670,279	451,316	316,054
CASH FLOWS FROM (USED IN) INVESTING ACTIVITIES:
Proceeds from sale of fixed maturity securities	1,293,876	1,554,906	2,436,258
Proceeds from sale of equity securities	159,827	137,990	188,646
Distributions from (contributions to) investment funds	(113,913)	(53,979)	(87,011)
Proceeds from maturities and prepayments of fixed maturity securities	1,697,144	1,374,378	1,214,157
Purchase of fixed maturity securities	(2,815,340)	(2,755,449)	(4,869,368)
Purchase of equity securities	(97,986)	(193,914)	(67,309)
Real Estate purchased	(96,552)	0	0
Change in loans receivable	92,176	23,317	(11,363)
Net additions to property, furniture and equipment	(45,320)	(49,605)	(30,455)
Change in balances due to (from) security brokers	(16,194)	(297)	144,023
Payment for business purchased, net of cash acquired	(261,992)	0	(33,812)
Net cash from (used in) investing activities	(204,274)	37,347	(1,116,234)
CASH FLOWS FROM (USED IN) FINANCING ACTIVITIES:
Net proceeds from issuance of debt	0	309,030	333,589
Net proceeds from stock options exercised	21,963	17,730	5,426
Repayment of senior notes and other debt	(1,310)	(162,685)	(11,165)
Cash dividends to common stockholders	(43,253)	(49,348)	(28,843)
Purchase of common treasury shares	(187,163)	(471,007)	(147,144)
Other	14,550	(2,795)	21,522
Net cash from (used in) financing activities	(195,213)	(359,075)	173,385
Net impact on cash due to change in foreign exchange rates	(2,002)	(2,066)	7,390
Net increase (decrease) in cash and cash equivalents	268,790	127,522	(619,405)
Cash and cash equivalents at beginning of year	642,952	515,430	1,134,835
Cash and cash equivalents at end of year	$ 911,742	$ 642,952	$ 515,430

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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).