Accumulated Other Comprehensive Income (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income and (Loss), Pre-Tax Amount, Beginning of period	$ 3,812,000	$ (352,000)	$ 1,804,000
Change in net unrealized gain (loss) on investments, Pre-Tax Amount	2,602,000	4,291,000	2,093,000
Reclassification adjustment for realized losses, Pre-Tax Amount	(2,160,000)	(158,000)	(4,346,000)
Other than Temporary Impairment Losses, Investments, Portion in Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	0	31,000	97,000
Accumulated Other Comprehensive Income and (Loss), Pre-Tax Amount, End of period	4,254,000	3,812,000	(352,000)
Deferred Tax Liabilities, Other Comprehensive Income	(1,471,000)	136,000	(696,000)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	(1,004,000)	(1,656,000)	(807,000)
Reclassification adjustment for realized losses, Tax (Expense) Benefit	834,000	61,000	1,676,000
Other than Temporary Impairment Losses, Investments, Portion in Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	0	(12,000)	(37,000)
Deferred Tax Liabilities, Other Comprehensive Income	(1,641,000)	(1,471,000)	136,000
Accumulated Other Comprehensive Income (Loss), Net-of-Tax Amount, Beginning of period	2,341,000	(216,000)	1,108,000
Change in net unrealized gain (loss) on investments, Net-of-Tax Amount	1,598,000	2,635,000	1,286,000
Reclassification adjustment for realized losses, Net-of-Tax Amount	(1,326,000)	(97,000)	(2,670,000)
Other than Temporary Impairment Losses, Investments, Portion in Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	0	19,000	60,000
Accumulated Other Comprehensive Income (Loss), Net-of-Tax Amount, End of period	$ 2,613,000	$ 2,341,000	$ (216,000)