Fair Value (Details) (Recurring [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
US government obligations	$ 75,562	$ 70,742
Residential mortgage-backed securities	23,190	25,040
Commercial mortgage-backed securities	12,444	11,828
State and municipal obligations	179,854	194,865
Corporate securities	117,835	118,945
Options embedded in convertible securities	1,882	1,651
Foreign government obligations	21,854	22,598
Total fixed maturities	432,621	445,669
Equity securities	115,377	107,582
Short term	3,740	4,201
Cash equivalents	80,032	64,450
Total fair value	631,770	621,902
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
US government obligations	75,562	70,742
Residential mortgage-backed securities	0	0
Commercial mortgage-backed securities	0	0
State and municipal obligations	0	0
Corporate securities	0	0
Options embedded in convertible securities	0	0
Foreign government obligations	0	0
Total fixed maturities	75,562	70,742
Equity securities	115,377	107,582
Short term	3,740	4,201
Cash equivalents	0	0
Total fair value	194,679	182,525
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
US government obligations	0	0
Residential mortgage-backed securities	23,190	25,040
Commercial mortgage-backed securities	12,444	11,828
State and municipal obligations	179,854	194,865
Corporate securities	107,362	107,263
Options embedded in convertible securities	1,882	1,651
Foreign government obligations	21,854	22,598
Total fixed maturities	346,586	363,245
Equity securities	0	0
Short term	0	0
Cash equivalents	80,032	64,450
Total fair value	426,618	427,695
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
US government obligations	0	0
Residential mortgage-backed securities	0	0
Commercial mortgage-backed securities	0	0
State and municipal obligations	0	0
Corporate securities	10,473	11,682
Options embedded in convertible securities	0	0
Foreign government obligations	0	0
Total fixed maturities	10,473	11,682
Equity securities	0	0
Short term	0	0
Cash equivalents	0	0
Total fair value	$ 10,473	$ 11,682