Investments (Schedule Of Default Assumptions By Moody's Rating Categories) (Details)	12 Months Ended
	Dec. 31, 2016
Investment Grade | Aaa - Bbb | Minimum
Financing Receivable, Recorded Investment [Line Items]
1-in-100 Year Default Rate	0.00%
Historical Mean Default Rate	0.00%
Investment Grade | Aaa - Bbb | Maximum
Financing Receivable, Recorded Investment [Line Items]
1-in-100 Year Default Rate	1.30%
Historical Mean Default Rate	0.30%
Below Investment Grade | Ba
Financing Receivable, Recorded Investment [Line Items]
1-in-100 Year Default Rate	4.80%
Historical Mean Default Rate	1.00%
Below Investment Grade | B
Financing Receivable, Recorded Investment [Line Items]
1-in-100 Year Default Rate	12.10%
Historical Mean Default Rate	3.20%
Below Investment Grade | Caa - C
Financing Receivable, Recorded Investment [Line Items]
1-in-100 Year Default Rate	36.70%
Historical Mean Default Rate	10.50%