Fair Value Measurements (Details 1) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2012 Carrying Amount [Member]	Dec. 31, 2011 Carrying Amount [Member]	Sep. 30, 2012 Fair Value [Member]	Dec. 31, 2011 Fair Value [Member]	Sep. 30, 2012 ACT II [Member]	May 31, 2012 ACT II [Member]	Sep. 30, 2012 ACT II [Member] Carrying Amount [Member]	Dec. 31, 2011 ACT II [Member] Carrying Amount [Member]	Sep. 30, 2012 ACT II [Member] Fair Value [Member]	Dec. 31, 2011 ACT II [Member] Fair Value [Member]
Summary of carrying or reported values and corresponding fair values for financial instruments
Fixed maturity securities-held-to-maturity	$ 607,681	$ 646,048			$ 607,681	$ 646,048	$ 654,175	$ 685,242
Securities available for sale-fixed maturity	147,131	100,742			147,131	100,742	147,131	100,742
Equity securities	7,117	12,240			7,117	12,240	7,117	12,240
Cash and cash equivalents	69,345	45,536	68,940	60,966	69,345	45,536	69,345	45,536
Short-term investments	51,345	46,944			51,345	46,944	51,345	46,944
Subordinated debt securities		$ 25,780							$ 25,800	$ 12,900		$ 25,780		$ 25,780