Investments Realized Gain (Loss) on Investments (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Gain (Loss) on Investments [Line Items]
Realized gains and losses on securities previously impaired	$ 600,000	$ 1,300,000	$ 6,400,000
Proceeds from Sale of Available-for-sale Securities, Fixed Maturities	576,000	0	8,029,000
Proceeds from Sale of Available-for-sale Securities, Equity	2,855,000	7,504,000	22,822,000
Gain (Loss) on Sale, Calls and Maturities of Fixed Maturities	824,000	119,000	753,000
Gain (Loss) on Sale of Equity Securities	636,000	1,259,000	7,343,000
Gain (Loss) on Sale of Property and Equipment	0	2,000	(8,000)
Gain (Loss) on Sale of Other Long-Term Investments	55,000	16,000	(49,000)
Gain (Loss) on Investments, Excluding Other than Temporary Impairments	1,515,000	1,396,000	8,039,000
Other-than-temporary Impairment Losses on Fixed Maturities	(1,319,000)	(70,000)	(27,000)
Other-than-temporary Impairment Losses on Other Long-Term Investments	0	(561,000)	0
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	(1,319,000)	(631,000)	(27,000)
Realized investment gains, net	196,000	765,000	8,012,000
Debt Securities [Member]
Gain (Loss) on Investments [Line Items]
Available-for-sale Securities, Gross Realized Gains	54,000	0	912,000
Available-for-sale Securities, Gross Realized Losses	3,000	0	25,000
Equity Securities [Member]
Gain (Loss) on Investments [Line Items]
Available-for-sale Securities, Gross Realized Gains	632,000	1,259,000	7,254,000
Available-for-sale Securities, Gross Realized Losses	0	0	11,000
Categories of Investments, Marketable Securities, Held-to-maturity Securities [Member]
Gain (Loss) on Investments [Line Items]
Gain (Loss) on Investments, Excluding Other than Temporary Impairments	$ 246,000