Fair Value Measurements (Summarize Changes in Level 3 Assets) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2012	Dec. 31, 2011
Beginning Balance	$ 82,541	$ 182,255
Earnings	1,883	29,065
Other Comprehensive Income	(457)	(31,735)
Purchases	74	15,540
(Sales)	(9,483)	(90,355)
Maturities	(3,488)	(22,318)
Transfer out	15	89
Ending Balance	71,085	82,541
Fixed Maturities Securities [Member]
Beginning Balance	67,828	88,063
Earnings	113	(454)
Other Comprehensive Income	1,294	(870)
Purchases	74	15,271
(Sales)	0	(11,864)
Maturities	(3,488)	(22,318)
Transfer out	0	0
Ending Balance	65,821	67,828
Equity Securities Available For Sale [Member]
Beginning Balance	13,862	91,005
Earnings	1,962	28,947
Other Comprehensive Income	(1,751)	(30,865)
Purchases	0	0
(Sales)	(9,483)	(75,225)
Maturities	0	0
Transfer out	0	0
Ending Balance	4,590	13,862
Securities Sold But Not Yet Purchased [Member]
Beginning Balance	21	0
Earnings	20	40
Other Comprehensive Income	0	0
Purchases	0	67
(Sales)	0	(86)
Maturities	0	0
Transfer out	0	0
Ending Balance	41	21
Corporate [Member] \| Fixed Maturities Securities [Member]
Beginning Balance	67,828	88,063
Earnings	113	(454)
Other Comprehensive Income	1,294	(870)
Purchases	74	15,271
(Sales)	0	(11,864)
Maturities	(3,488)	(22,318)
Transfer out	0	0
Ending Balance	65,821	67,828
Common Stock [Member] \| Equity Securities Available For Sale [Member]
Beginning Balance	1,559	1,559
Earnings	0	0
Other Comprehensive Income	0	0
Purchases	0	0
(Sales)	(150)	0
Maturities	0	0
Transfer out	0	0
Ending Balance	1,409	1,559
Preferred Stock [Member] \| Equity Securities Available For Sale [Member]
Beginning Balance	12,303	89,446
Earnings	1,962	28,947
Other Comprehensive Income	(1,751)	(30,865)
Purchases	0	0
(Sales)	(9,333)	(75,225)
Maturities	0	0
Transfer out	0	0
Ending Balance	3,181	12,303
Arbitrage Trading Account [Member]
Beginning Balance	851	3,187
Earnings	(192)	572
Other Comprehensive Income	0	0
Purchases	0	269
(Sales)	0	3,266
Maturities	0	0
Transfer out	15	89
Ending Balance	$ 674	$ 851

This element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c(1)

-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.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258

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- Definition

This element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity).

+ References

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Balance Type:	debit
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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

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)(2)

-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258

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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.

+ References

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Balance Type:	credit
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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.

+ References

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Balance Type:	credit
Period Type:	duration

- Definition

This element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c(3)

-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.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(3)

-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258

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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 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.

Reference 2: 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=6925170&loc=d3e19207-110258

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