Investments (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Fixed maturity securities:
Amortized cost	$ 721,467	$ 761,441
Gross unrealized gains	70,632	56,077
Gross unrealized losses	(338)	(1,519)
Estimated fair value	791,761	815,999
U.S. Treasury securities and other government corporations and agencies [Member]
Fixed maturity securities:
Amortized cost	49,624	58,814
Gross unrealized gains	3,912	4,315
Gross unrealized losses		(39)
Estimated fair value	53,536	63,090
States of the U.S. and political subdivisions of the states [Member]
Fixed maturity securities:
Amortized cost	41,204	27,676
Gross unrealized gains	6,106	4,581
Gross unrealized losses	(57)
Estimated fair value	47,253	32,257
Corporate securities [Member]
Fixed maturity securities:
Amortized cost	288,141	298,452
Gross unrealized gains	38,320	29,601
Gross unrealized losses	(51)	(1,127)
Estimated fair value	326,410	326,926
Mortgage-backed securities [Member]
Fixed maturity securities:
Amortized cost	214,995	257,864
Gross unrealized gains	14,079	12,973
Gross unrealized losses	(102)	(26)
Estimated fair value	228,972	270,811
Commercial mortgage-backed securities [Member]
Fixed maturity securities:
Amortized cost	66,279	60,198
Gross unrealized gains	5,737	3,941
Gross unrealized losses	(98)	(178)
Estimated fair value	71,918	63,961
Asset-backed securities [Member]
Fixed maturity securities:
Amortized cost	61,224	58,437
Gross unrealized gains	2,478	666
Gross unrealized losses	(30)	(149)
Estimated fair value	63,672	58,954
Common stock [Member]
Fixed maturity securities:
Amortized cost	6,926	6,926
Gross unrealized gains
Gross unrealized losses	(220)	(175)
Estimated fair value	6,706	6,751
Preferred stock [Member]
Fixed maturity securities:
Amortized cost	2,789	2,789
Gross unrealized gains	288	212
Gross unrealized losses	(12)	(69)
Estimated fair value	$ 3,065	$ 2,932

Amount of debt securities categorized neither as held-to-maturity nor trading.

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

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15C

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 12

-Subparagraph b

-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 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 137

-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 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 16

-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 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 320

-Section 50

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 22

-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 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 13

-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 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15D

-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.

+ Details

- Definition

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details