Summary of Investments (Net Realized Investment Gains and Losses) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Gain (Loss) on Investments [Line Items]
Net realized investment gains (losses)	$ 1,909	$ 2,794
Available-for-sale Securities [Abstract]
Proceeds from sales	2,810	3,000
Gross realized gains	142	470
Gross realized losses	0	(25)
Fixed Maturities [Member] \| Available-for-sale Securities [Member]
Gain (Loss) on Investments [Line Items]
Net realized investment gains (losses)	720	1,531
Fixed Maturities [Member] \| Trading Securities, Change in Fair Value [Member]
Gain (Loss) on Investments [Line Items]
Net realized investment gains (losses)	560	191
Fixed Maturities [Member] \| Trading Securities, Sales [Member]
Gain (Loss) on Investments [Line Items]
Net realized investment gains (losses)	0	371
Equity Securities [Member] \| Available-for-sale Securities [Member]
Gain (Loss) on Investments [Line Items]
Net realized investment gains (losses)	516	701
Equity Securities [Member] \| Trading Securities, Change in Fair Value [Member]
Gain (Loss) on Investments [Line Items]
Net realized investment gains (losses)	$ 113	$ 0

The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 16

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26853-111562

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 16

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 18

-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 95

-Paragraph 15

-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 Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 12

-Subparagraph (a),(b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3179-108585

+ Details