Investments (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Fixed maturity securities:
Amortized cost	$ 307,770	$ 765,359
Gross unrealized gains	8,100	65,034
Gross unrealized losses	(4,561)	(816)
Estimated fair value	311,309	829,577
U.S. Treasury securities and other government corporations and agencies [Member]
Fixed maturity securities:
Amortized cost	258,887	53,591
Gross unrealized gains	2,017	2,961
Gross unrealized losses	(3,951)	(11)
Estimated fair value	256,953	56,541
States of the U.S. and political subdivisions of the states [Member]
Fixed maturity securities:
Amortized cost	4,516	40,100
Gross unrealized gains	92	6,064
Gross unrealized losses	(183)
Estimated fair value	4,425	46,164
Corporate securities [Member]
Fixed maturity securities:
Amortized cost	30,401	304,725
Gross unrealized gains	5,074	36,089
Gross unrealized losses	(207)	(85)
Estimated fair value	35,268	340,729
Mortgage-backed securities [Member]
Fixed maturity securities:
Amortized cost	4,978	237,653
Gross unrealized gains	90	11,088
Gross unrealized losses	(202)	(501)
Estimated fair value	4,866	248,240
Commercial mortgage-backed securities [Member]
Fixed maturity securities:
Amortized cost	2,684	57,521
Gross unrealized gains	141	5,694
Gross unrealized losses
Estimated fair value	2,825	63,215
Asset-backed securities [Member]
Fixed maturity securities:
Amortized cost	6,304	71,769
Gross unrealized gains	686	3,138
Gross unrealized losses	(18)	(219)
Estimated fair value	6,972	74,688
Common stock [Member]
Fixed maturity securities:
Amortized cost	6,926	9,004
Gross unrealized gains		6
Gross unrealized losses	(853)	(234)
Estimated fair value	6,073	8,776
Preferred stock [Member]
Fixed maturity securities:
Amortized cost		2,789
Gross unrealized gains	39	317
Gross unrealized losses		(25)
Estimated fair value	$ 39	$ 3,081

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

Reference 1: 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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7534914&loc=d3e22054-111558

Reference 3: 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 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 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 6: 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 7: 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.

Reference 8: 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 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 320

-Section 50

-Paragraph 2

-Subparagraph (b)-(g)

-URI http://asc.fasb.org/extlink&oid=6957658&loc=d3e62557-112803

+ 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