SCHEDULE I -SUMMARY OF INVESTMENTS-OTHER THAN INVESTMENTS IN RELATED PARTIES (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Amount at which shown in the balance sheet	$ 35,300
Money markets fund classified with cash and cash equivalent and excluded from other investments in related party	64,450
Total Investments [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	562,841
Fair value	617,406
Amount at which shown in the balance sheet	617,406	[1]
Limited Partnership [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	59,954
Fair value	59,954
Amount at which shown in the balance sheet	59,954	[1]
Bonds [Member] | Total Fixed Maturities [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	440,559
Fair value	445,669
Amount at which shown in the balance sheet	445,669	[1]
Bonds [Member] | U.S Government Obligations [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	70,720
Fair value	70,742
Amount at which shown in the balance sheet	70,742	[1]
Bonds [Member] | Mortgage-backed Securities [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	34,960
Fair value	36,868
Amount at which shown in the balance sheet	36,868	[1]
Bonds [Member] | State and Municipal Obligations [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	194,258
Fair value	194,865
Amount at which shown in the balance sheet	194,865	[1]
Bonds [Member] | Foreign Government Obligations [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	22,047
Fair value	22,598
Amount at which shown in the balance sheet	22,598	[1]
Bonds [Member] | Corporate Securities [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	118,574
Fair value	120,596
Amount at which shown in the balance sheet	120,596	[1]
Common Stocks [Member] | Total Equity Securities [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	58,127
Fair value	107,582
Amount at which shown in the balance sheet	107,582	[1]
Common Stocks [Member] | Industrial, Miscellaneous, and All Others [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	58,127
Fair value	107,582
Amount at which shown in the balance sheet	107,582	[1]
Short-term [Member] | Total Short-term and Other [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	4,201
Fair value	4,201
Amount at which shown in the balance sheet	4,201	[1]
Short-term [Member] | Certificates of Deposit [Member]
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	4,201
Fair value	4,201
Amount at which shown in the balance sheet	$ 4,201	[1]

[1] Investments presented above do not include $64,450 of money market funds classified with cash and cash equivalents in the balance sheet.