Guaranteed Benefit Features (Narrative) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Guaranteed Benefit Features [Abstract]
Percent of permanent life insurance in force	35.00%		35.00%		35.00%
Percent of permanent life insurance sales	38.00%	26.00%	34.00%	27.00%