INVESTMENTS (Details 4) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Assets measured at Fair Value
Trading securities:	$ 7	$ 15
Available-for-sale securities:	1,535,006	1,453,961
Non-U.S. govt. & agency
Assets measured at Fair Value
Available-for-sale securities:	6,697	1,557
US Government Agencies Debt Securities [Member]
Assets measured at Fair Value
Available-for-sale securities:	113,819	102,213
Equities
Assets measured at Fair Value
Available-for-sale securities:	388,689	321,897
Fair value measured on recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets measured at Fair Value
Available-for-sale securities:	388,689	321,897
Total assets at fair value	388,689	321,897
Fair value measured on recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Equities
Assets measured at Fair Value
Available-for-sale securities:	388,689	321,897
Fair value measured on recurring basis \| Significant Other Observable Inputs (Level 2)
Assets measured at Fair Value
Trading securities:	7	15
Available-for-sale securities:	1,146,317	1,132,064
Total assets at fair value	1,146,324	1,132,079
Fair value measured on recurring basis \| Significant Other Observable Inputs (Level 2) \| Mortgage-backed:
Assets measured at Fair Value
Trading securities:	7	15
Available-for-sale securities:	248,986	254,141
Fair value measured on recurring basis \| Significant Other Observable Inputs (Level 2) \| ABS/CMO:
Assets measured at Fair Value
Available-for-sale securities:	56,953	49,915
Fair value measured on recurring basis \| Significant Other Observable Inputs (Level 2) \| Non-U.S. govt. & agency
Assets measured at Fair Value
Available-for-sale securities:	6,697	1,557
Fair value measured on recurring basis \| Significant Other Observable Inputs (Level 2) \| US Treasury Securities [Member]
Assets measured at Fair Value
Available-for-sale securities:	16,172	15,824
Fair value measured on recurring basis \| Significant Other Observable Inputs (Level 2) \| US Government Agencies Debt Securities [Member]
Assets measured at Fair Value
Available-for-sale securities:	113,819	102,213
Fair value measured on recurring basis \| Significant Other Observable Inputs (Level 2) \| Corporates
Assets measured at Fair Value
Available-for-sale securities:	467,100	471,376
Fair value measured on recurring basis \| Significant Other Observable Inputs (Level 2) \| Municipals
Assets measured at Fair Value
Available-for-sale securities:	236,590	237,038
Fair value measured on recurring basis \| Total
Assets measured at Fair Value
Trading securities:	7	15
Available-for-sale securities:	1,535,006	1,453,961
Total assets at fair value	1,535,013	1,453,976
Fair value measured on recurring basis \| Total \| Mortgage-backed:
Assets measured at Fair Value
Trading securities:	7	15
Available-for-sale securities:	248,986	254,141
Fair value measured on recurring basis \| Total \| ABS/CMO:
Assets measured at Fair Value
Available-for-sale securities:	56,953	49,915
Fair value measured on recurring basis \| Total \| Non-U.S. govt. & agency
Assets measured at Fair Value
Available-for-sale securities:	6,697	1,557
Fair value measured on recurring basis \| Total \| US Treasury Securities [Member]
Assets measured at Fair Value
Available-for-sale securities:	16,172	15,824
Fair value measured on recurring basis \| Total \| US Government Agencies Debt Securities [Member]
Assets measured at Fair Value
Available-for-sale securities:	113,819	102,213
Fair value measured on recurring basis \| Total \| Corporates
Assets measured at Fair Value
Available-for-sale securities:	467,100	471,376
Fair value measured on recurring basis \| Total \| Municipals
Assets measured at Fair Value
Available-for-sale securities:	236,590	237,038
Fair value measured on recurring basis \| Total \| Equities
Assets measured at Fair Value
Available-for-sale securities:	$ 388,689	$ 321,897

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

+ References+ Details

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Trading Securities which consist of all investments in certain debt and equity securities that are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time) or for which an entity has elected the fair value option. Trading generally reflects active and frequent buying and selling, and trading securities are generally used with the objective of generating profits on short-term differences in price, but this category of investments may also include items which are not intended to be sold in the near term or for which the fair value option has been elected.

+ References+ Details