v3.8.0.1
Schedule IV - Reinsurance (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Reinsurance Face Amount/Premiums for Insurance Companies, by Product Segment [Line Items]      
Gross Amount $ 3,733,997 $ 3,652,206 $ 3,457,711
Ceded to Other Companies 767,499 706,918 642,525
Assumed from Other Companies 207,083 218,262 235,418
Net Amount $ 3,173,581 $ 3,163,550 $ 3,050,604
Percentage of Amount Assumed to Net 6.50% 6.90% 7.70%
Gross Amount $ 31,797 $ 30,654 $ 27,996
Ceded to Other Companies 1,811 1,763 1,622
Assumed from Other Companies 2,105 2,073 2,147
Premiums $ 32,091 $ 30,964 $ 28,521
Percentage of Amount Assumed to Net 6.60% 6.70% 7.50%
Life Insurance      
Reinsurance Face Amount/Premiums for Insurance Companies, by Product Segment [Line Items]      
Gross Amount $ 29,035 $ 27,857 $ 25,346
Ceded to Other Companies 1,761 1,719 1,573
Assumed from Other Companies 2,105 2,073 2,147
Premiums $ 29,379 $ 28,211 $ 25,920
Percentage of Amount Assumed to Net 7.20% 7.30% 8.30%
Accident and Health Insurance      
Reinsurance Face Amount/Premiums for Insurance Companies, by Product Segment [Line Items]      
Gross Amount $ 2,762 $ 2,797 $ 2,650
Ceded to Other Companies 50 44 49
Assumed from Other Companies 0 0 0
Premiums $ 2,712 $ 2,753 $ 2,601
Percentage of Amount Assumed to Net 0.00% 0.00% 0.00%