v3.8.0.1
Business and Basis of Presentation (Narrative) (Details)
$ in Millions
3 Months Ended 12 Months Ended
Jun. 30, 2016
USD ($)
Dec. 31, 2017
segment
division
Dec. 31, 2016
USD ($)
Error Corrections and Prior Period Adjustments Restatement [Line Items]      
Number of Reportable Segments | segment   7  
Number of divisions | division   5  
Universal Life      
Error Corrections and Prior Period Adjustments Restatement [Line Items]      
Out of period decrease adjustments $ (148)   $ (141)
Income From Continuing Operations Before Income Taxes And Equity In Earnings Of Operating Joint Ventures      
Error Corrections and Prior Period Adjustments Restatement [Line Items]      
Out of period decrease adjustments $ (153)   $ (134)