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Investments (Held-To-Maturity Securities Disclosure) (Details) (USD $) | Jun. 30, 2011 securities years | Dec. 31, 2010 securities years
--- | --- | ---
Amortized Cost | $ 1,059,314,000 |  | $ 1,199,801,000 |
Net Unrealized Gains (Losses) | 11,264,000 |  | 14,523,000 |
Carrying Value | 1,070,578,000 |  | 1,214,324,000 |
Unrecognized Holding Gains | 51,896,000 |  | 43,998,000 |
Unrecognized Holding Losses | (1,497,000) |  | (2,028,000) |
Fair Value | 1,120,977,000 |  | 1,256,294,000 |
Held To Maturity securities average duration | 3.2 |  | 3.4 |
U.S. Government and Government Agencies [Member] |  |  |  |
Amortized Cost | 86,479,000 |  | 93,411,000 |
Net Unrealized Gains (Losses) | 4,280,000 |  | 4,695,000 |
Carrying Value | 90,759,000 |  | 98,106,000 |
Unrecognized Holding Gains | 6,336,000 |  | 5,023,000 |
Unrecognized Holding Losses | 0 |  | 0 |
Fair Value | 97,095,000 |  | 103,129,000 |
Foreign Government [Member] |  |  |  |
Amortized Cost | 5,292,000 |  | 5,292,000 |
Net Unrealized Gains (Losses) | 330,000 |  | 368,000 |
Carrying Value | 5,622,000 |  | 5,660,000 |
Unrecognized Holding Gains | 0 |  | 0 |
Unrecognized Holding Losses | (167,000) |  | (30,000) |
Fair Value | 5,455,000 |  | 5,630,000 |
Obligations of States and Political Subdivisions [Member] |  |  |  |
Amortized Cost | 779,013,000 |  | 874,388,000 |
Net Unrealized Gains (Losses) | 17,284,000 |  | 22,183,000 |
Carrying Value | 796,297,000 |  | 896,571,000 |
Unrecognized Holding Gains | 25,828,000 |  | 16,845,000 |
Unrecognized Holding Losses | (594,000) |  | (1,132,000) |
Fair Value | 821,531,000 |  | 912,284,000 |
Corporate Securities [Member] |  |  |  |
Amortized Cost | 72,739,000 |  | 76,663,000 |
Net Unrealized Gains (Losses) | (3,023,000) |  | (3,990,000) |
Carrying Value | 69,716,000 |  | 72,673,000 |
Unrecognized Holding Gains | 8,027,000 |  | 9,705,000 |
Unrecognized Holding Losses | (8,000) |  | (313,000) |
Fair Value | 77,735,000 |  | 82,065,000 |
Asset-backed Securities ("ABS") [Member] |  |  |  |
Amortized Cost | 10,238,000 |  | 12,947,000 |
Net Unrealized Gains (Losses) | (2,255,000) |  | (2,422,000) |
Carrying Value | 7,983,000 |  | 10,525,000 |
Unrecognized Holding Gains | 1,803,000 |  | 1,847,000 |
Unrecognized Holding Losses | (510,000) |  | (444,000) |
Fair Value | 9,276,000 |  | 11,928,000 |
Commercial Mortgage-backed Securities ("CMBS") [Member] |  |  |  |
Amortized Cost | 42,784,000 |  | 54,909,000 |
Net Unrealized Gains (Losses) | (6,181,000) |  | (7,354,000) |
Carrying Value | 36,603,000 | [1] | 47,555,000 | [1]
Unrecognized Holding Gains | 7,470,000 |  | 7,483,000 |
Unrecognized Holding Losses | (218,000) |  | (109,000) |
Fair Value | 43,855,000 |  | 54,929,000 |
Government Guaranteed Agency Securities Carrying Value | 5,000,000 |  | 8,900,000 |
Residential Mortgage Backed Securities ("RMBS") [Member] |  |  |  |
Amortized Cost | 62,769,000 |  | 82,191,000 |
Net Unrealized Gains (Losses) | 829,000 |  | 1,043,000 |
Carrying Value | 63,598,000 | [2] | 83,234,000 | [2]
Unrecognized Holding Gains | 2,432,000 |  | 3,095,000 |
Unrecognized Holding Losses | 0 |  | 0 |
Fair Value | 66,030,000 |  | 86,329,000 |
Government Guaranteed Agency Securities Carrying Value | $ 6,900,000 |  | $ 4,000,000 |
[1] | 1 CMBS includes government guaranteed agency securities with a carrying value of $5.0 million at June 30, 2011 and $8.9 million at December 31, 2010.
[2] | 2 RMBS includes government guaranteed agency securities with a carrying value of $6.9 million at June 30, 2011 and $4.0 million at December 31, 2010.

X
- Definition For an unclassified balance sheet, this item represents investments in debt securities which are categorized as held-to-maturity; such investments are measured at carrying value, which represents amortized cost adjusted for net unrealized gains (losses) resulting from: (i) an other-than-temporary impairment; or (ii) a previous available-for-sale designation. The held-to-maturity category is for those securities that the Entity has the positive intent and ability to hold until maturity. + Details
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- Definition The carrying value of agency securities that are issued by a particular agency of the federal government which are guaranteed by the U.S. government. + Details
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- Definition This item represents debt securities categorized as held-to-maturity, at cost, net of adjustments made for amortization and net unrealized gains (losses) resulting from: (i) other-than-temporary impairments and (ii) a previous available-for-sale designation. + Details
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- Definition As of the balance sheet date, the excess of fair value over carrying value of a debt security categorized as held-to-maturity, exclusive of dividend or interest income recognized but not yet received and exclusive of any write-downs for other-than-temporary impairment. Such item represents the gross unrecognized holding gain. + Details
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- Definition As of the balance sheet date, the excess of carrying value over fair value of a debt security categorized as held-to-maturity, exclusive of dividend or interest income recognized but not yet received and exclusive of any write-downs for other-than-temporary impairment. Such item represents the gross unrecognized holding loss. + Details
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- Definition The remaining aggregate increase (decrease) in the market value of held-to-maturity securities either (i) prior to the securities' transfer to a held-to-maturity designation or (ii) resulting from a non-credit other-than-temporary impairment. + Details
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- Definition This item represents the aggregate fair value of investments in debt securities as of the balance sheet date and which are categorized as held-to-maturity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 19 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 137 + Details
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