Investments (Commercial Mortgage and Other Loans) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2013	Dec. 31, 2012
Commercial mortgage loans	$ 382,098	$ 379,132
Commercial mortgage loans, Percentage	88.50%	88.30%
Valuation allowance	(2,139)	(2,177)
Total net commercial and agricultural mortgage loans by property type	429,476	426,981
Total commercial mortgage and other loans, net of valuation allowance	432,216	426,981
Total Commercial Mortgage By Propterty Type	431,615	429,158
Other Loans and Leases Receivable	2,740	0
Valuation Allowance - Other	0	0
Total Net Other Loans	2,740	0
Office buildings [Member]
Commercial mortgage loans	62,954	59,074
Commercial mortgage loans, Percentage	14.60%	13.80%
Retail stores [Member]
Commercial mortgage loans	71,178	71,546
Commercial mortgage loans, Percentage	16.50%	16.70%
Apartment Complexes [Member]
Commercial mortgage loans	118,732	120,066
Commercial mortgage loans, Percentage	27.50%	28.00%
Industrial Buildings [Member]
Commercial mortgage loans	113,894	114,619
Commercial mortgage loans, Percentage	26.40%	26.70%
Agricultural Properties [Member]
Commercial mortgage loans	49,517	50,026
Commercial mortgage loans, Percentage	11.50%	11.70%
Hospitality [Member]
Commercial mortgage loans	4,613	4,621
Commercial mortgage loans, Percentage	(1.10%)	(1.10%)
Other [Member]
Commercial mortgage loans	10,727	9,206
Commercial mortgage loans, Percentage	2.50%	2.00%
California [Member]
Commercial mortgage loans, Percentage	17.00%
Ohio [Member]
Commercial mortgage loans, Percentage	11.00%
New York [Member]
Commercial mortgage loans, Percentage	14.00%
Total Percentage [Member]
Commercial mortgage loans, Percentage	100.00%	100.00%
Uncollateralized Loans [Member]
Other Loans and Leases Receivable	$ 2,740	$ 0

The allowance for commercial loan and lease losses represents the reserve to cover probable credit losses related to specifically identified commercial loans and leases, as well as probable credit losses inherent in the remainder of the commercial loan portfolio as of the balance sheet date. For banks, include currently required allocated transfer risk reserves. Include carryover of or adjustments to the allowance for commercial loan losses in connection with business combinations determined to be appropriate.

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

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Section 563c.102

-Paragraph 8

-Subparagraph a(ii)

-Chapter V

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-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It 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 310

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-Section 50

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 9

-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

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

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

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

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-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 SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph d

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Reference 11: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 8

-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

Amount before allowance of other loans and leases not otherwise specified in the taxonomy. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References+ Details

- Definition

Amount before allowance of mortgage loans on existing land or building. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.

+ References+ Details