Investments (Details 2) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Gross unrealized losses of the Company's investment portfolio
Less than 12 months, Fair Value	$ 14,932	$ 71,069
12 months or longer, Fair Value	4,102	5,432
Total, Fair Value	19,034	76,501
Temporarily impaired securities, Less than 12 months, Fair Value	22,137	79,256
Temporarily impaired securities, 12 months or longer, Fair Value	4,618	5,941
Temporarily impaired securities, Fair Value	26,755	85,197
Less than 12 months, Unrealized Losses	(393)	(1,476)
12 months or longer, Unrealized Losses	(28)	(43)
Total, Unrealized Losses	(421)	(1,519)
Temporarily impaired securities, Less than 12 months, Unrealized Losses	(614)	(1,701)
Temporarily impaired securities, 12 months or longer, Unrealized Losses	(39)	(62)
Temporarily impaired securities, Unrealized Losses	(653)	(1,763)
U.S. Treasury securities and other government corporations and agencies [Member]
Gross unrealized losses of the Company's investment portfolio
Less than 12 months, Fair Value		3,749
12 months or longer, Fair Value
Total, Fair Value		3,749
Less than 12 months, Unrealized Losses		(39)
12 months or longer, Unrealized Losses
Total, Unrealized Losses		(39)
States of the U.S. and political subdivisions of the states [Member]
Gross unrealized losses of the Company's investment portfolio
Less than 12 months, Fair Value	1,098
12 months or longer, Fair Value
Total, Fair Value	1,098
Less than 12 months, Unrealized Losses	(9)
12 months or longer, Unrealized Losses
Total, Unrealized Losses	(9)
Corporate securities [Member]
Gross unrealized losses of the Company's investment portfolio
Less than 12 months, Fair Value	2,916	31,808
Total, Fair Value	2,916	31,808
Less than 12 months, Unrealized Losses	(205)	(1,127)
Total, Unrealized Losses	(205)	(1,127)
Mortgage-backed securities [Member]
Gross unrealized losses of the Company's investment portfolio
Less than 12 months, Fair Value	6,426	6,574
Total, Fair Value	6,426	6,574
Less than 12 months, Unrealized Losses	(115)	(26)
Total, Unrealized Losses	(115)	(26)
Commercial mortgage-backed securities [Member]
Gross unrealized losses of the Company's investment portfolio
Less than 12 months, Fair Value		13,401
12 months or longer, Fair Value	4,051	5,432
Total, Fair Value	4,051	18,833
Less than 12 months, Unrealized Losses		(135)
12 months or longer, Unrealized Losses	(14)	(43)
Total, Unrealized Losses	(14)	(178)
Asset-backed securities [Member]
Gross unrealized losses of the Company's investment portfolio
Less than 12 months, Fair Value	4,492	15,537
12 months or longer, Fair Value	51
Total, Fair Value	4,543	15,537
Less than 12 months, Unrealized Losses	(64)	(149)
12 months or longer, Unrealized Losses	(14)
Total, Unrealized Losses	(78)	(149)
Common stock [Member]
Gross unrealized losses of the Company's investment portfolio
Temporarily impaired securities, Less than 12 months, Fair Value	6,706	6,751
Temporarily impaired securities, Fair Value	6,706	6,751
Temporarily impaired securities, Less than 12 months, Unrealized Losses	(220)	(175)
Temporarily impaired securities, Unrealized Losses	(220)	(175)
Preferred stock [Member]
Gross unrealized losses of the Company's investment portfolio
Temporarily impaired securities, Less than 12 months, Fair Value	499	1,436
Temporarily impaired securities, 12 months or longer, Fair Value	516	509
Temporarily impaired securities, Fair Value	1,015	1,945
Temporarily impaired securities, Less than 12 months, Unrealized Losses	(1)	(50)
Temporarily impaired securities, 12 months or longer, Unrealized Losses	(11)	(19)
Temporarily impaired securities, Unrealized Losses	$ (12)	$ (69)