Investments (Significant Assumptions Used to Determine the Credit Loss Component of Other Than Temporary Impariment on Residential Mortgage Backed Securities) (Details) - Residential Mortgage Backed Securities [Member]	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Prime Sector [Member] | Vintage Year 2005 [Member] | Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Discount rate		7.50%
Default rate		15.00%
Loss severity		50.00%
Prime Sector [Member] | Vintage Year 2005 [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Discount rate		7.50%
Default rate		15.00%
Loss severity		50.00%
Prime Sector [Member] | Vintage Year 2006 [Member] | Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Discount rate	6.50%	6.50%
Default rate	12.00%	11.00%
Loss severity	40.00%	40.00%
Prime Sector [Member] | Vintage Year 2006 [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Discount rate	7.40%	7.40%
Default rate	14.00%	15.00%
Loss severity	50.00%	50.00%
Prime Sector [Member] | Vintage Year 2007 [Member] | Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Discount rate	5.80%	7.00%
Default rate	15.00%	14.00%
Loss severity	45.00%	55.00%
Prime Sector [Member] | Vintage Year 2007 [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Discount rate	7.00%	7.00%
Default rate	25.00%	14.00%
Loss severity	55.00%	55.00%
Alt-A Sector [Member] | Vintage Year 2005 [Member] | Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Discount rate	5.60%	5.60%
Default rate	13.00%	87.00%
Loss severity	2.00%	2.00%
Alt-A Sector [Member] | Vintage Year 2005 [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Discount rate	7.40%	6.40%
Default rate	99.00%	91.00%
Loss severity	50.00%	2.00%