Rollforward of Level 3 Assets Measured on a Recurring Basis (Details) (Fair Value, Recurring Measurements [Member], Level 3 [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Fair Value, Recurring Measurements [Member] \| Level 3 [Member]
Fair Value, Assets Measured on a Recurring Basis, Unobservable Input Reconciliation [Line Items]
Level 3 assets, beginning of period	$ 10,131	$ 12,265	$ 6,937	$ 24,998
Net unrealized gains (losses) included in other comprehensive income	206	(454)	(130)	(735)
Net realized gains (losses) included in realized investments gains, including other-than-temporary impairment losses	50	158	10	1,624
Purchases	757	13,609	3,173	17,609
Sales	0	0	0	(3,823)
Settlements	(3,162)	(193)	(3,900)	(1,655)
Transfers into level 3	0	488	2,951	4,991
Transfers out of level 3	(1,140)	(4,815)	(2,199)	(21,951)
Level 3 assets, end of period	$ 6,842	$ 21,058	$ 6,842	$ 21,058

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Amount of gain (loss) recognized in earnings, arising from assets measured at fair value on a recurring basis using unobservable inputs (level 3).

+ References

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- Definition

Amount of gain (loss) recognized in other comprehensive income, arising from assets measured at fair value on a recurring basis using unobservable inputs (level 3).

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- Definition

Purchases that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.

+ References

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- Definition

Sales that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.

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- Definition

Settlements that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.

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- Definition

Transfers into assets measured at fair value and categorized within Level 3 of the fair value hierarchy that have taken place during the period.

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- Definition

Transfers out of assets measured at fair value and categorized within Level 3 of the fair value hierarchy that have taken place during the period.

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- Definition

This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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