Derivative Instruments (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
AOCI Cash Flow Hedges [Roll Forward]
Accumulated Other Comprehensive Income Loss Related To Cash Flow Hedge	$ (828,000)	$ 0
Unrealized Gain (Loss) on Interest Rate Cash Flow Hedges, Pretax, Accumulated Other Comprehensive Income (Loss)	2,613,000	(628,000)
Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	0	0
Cash Flow Hedge Gain (Loss) Reclassified to Investment Income, Net	(1,382,000)	(200,000)
Accumulated Other Comprehensive Income Loss Related To Cash Flow Hedge	$ 403,000	$ (828,000)