Insurance (Short-Duration Contracts Historical Claims) (Details)	Dec. 31, 2018
Group Life - Term
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Short-duration Insurance Contracts, Historical Claims Duration, Year One	78.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Two	20.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Three	0.70%
Short-duration Insurance Contracts, Historical Claims Duration, Year Four	0.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Five	0.40%
Short-duration Insurance Contracts, Historical Claims Duration, Year Six	0.10%
Short-duration Insurance Contracts, Historical Claims Duration, Year Seven	0.00%
Short-duration Insurance Contracts, Historical Claims Duration, Year Eight	0.00%
Group Life - Term | Asia
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Short-duration Insurance Contracts, Historical Claims Duration, Year One	23.90%
Short-duration Insurance Contracts, Historical Claims Duration, Year Two	25.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Three	12.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Four	8.90%
Short-duration Insurance Contracts, Historical Claims Duration, Year Five	8.90%
Short-duration Insurance Contracts, Historical Claims Duration, Year Six	8.80%
Short-duration Insurance Contracts, Historical Claims Duration, Year Seven	8.30%
Short-duration Insurance Contracts, Historical Claims Duration, Year Eight	3.90%
Short-duration Insurance Contracts, Historical Claims Duration, Year Nine	3.80%
Group Long-Term Disability
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Short-duration Insurance Contracts, Historical Claims Duration, Year One	4.40%
Short-duration Insurance Contracts, Historical Claims Duration, Year Two	18.90%
Short-duration Insurance Contracts, Historical Claims Duration, Year Three	14.00%
Short-duration Insurance Contracts, Historical Claims Duration, Year Four	8.60%
Short-duration Insurance Contracts, Historical Claims Duration, Year Five	7.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Six	6.50%
Short-duration Insurance Contracts, Historical Claims Duration, Year Seven	5.60%
Short-duration Insurance Contracts, Historical Claims Duration, Year Eight	5.10%
Property & Casualty - Auto
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Short-duration Insurance Contracts, Historical Claims Duration, Year One	39.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Two	31.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Three	14.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Four	8.00%
Short-duration Insurance Contracts, Historical Claims Duration, Year Five	4.00%
Short-duration Insurance Contracts, Historical Claims Duration, Year Six	1.80%
Short-duration Insurance Contracts, Historical Claims Duration, Year Seven	0.90%
Short-duration Insurance Contracts, Historical Claims Duration, Year Eight	0.40%
Short-duration Insurance Contracts, Historical Claims Duration, Year Nine	0.10%
Short-duration Insurance Contracts, Historical Claims Duration, Year Ten	0.00%
Property & Casualty - Home
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Short-duration Insurance Contracts, Historical Claims Duration, Year One	79.80%
Short-duration Insurance Contracts, Historical Claims Duration, Year Two	15.70%
Short-duration Insurance Contracts, Historical Claims Duration, Year Three	2.10%
Short-duration Insurance Contracts, Historical Claims Duration, Year Four	1.00%
Short-duration Insurance Contracts, Historical Claims Duration, Year Five	0.40%
Short-duration Insurance Contracts, Historical Claims Duration, Year Six	0.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Seven	0.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Eight	0.00%
Short-duration Insurance Contracts, Historical Claims Duration, Year Nine	0.00%
Short-duration Insurance Contracts, Historical Claims Duration, Year Ten	0.10%
Protection Life | Latin America
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Short-duration Insurance Contracts, Historical Claims Duration, Year One	62.40%
Short-duration Insurance Contracts, Historical Claims Duration, Year Two	28.40%
Short-duration Insurance Contracts, Historical Claims Duration, Year Three	2.70%
Short-duration Insurance Contracts, Historical Claims Duration, Year Four	0.70%
Short-duration Insurance Contracts, Historical Claims Duration, Year Five	0.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Six	0.10%
Short-duration Insurance Contracts, Historical Claims Duration, Year Seven	0.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Eight	0.30%
Short-duration Insurance Contracts, Historical Claims Duration, Year Nine	0.70%
Short-duration Insurance Contracts, Historical Claims Duration, Year Ten	0.30%
Protection Health | Latin America
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Short-duration Insurance Contracts, Historical Claims Duration, Year One	87.30%
Short-duration Insurance Contracts, Historical Claims Duration, Year Two	11.30%
Short-duration Insurance Contracts, Historical Claims Duration, Year Three	0.60%
Short-duration Insurance Contracts, Historical Claims Duration, Year Four	0.00%
Short-duration Insurance Contracts, Historical Claims Duration, Year Five	0.00%
Short-duration Insurance Contracts, Historical Claims Duration, Year Six	0.00%
Short-duration Insurance Contracts, Historical Claims Duration, Year Seven	(0.30%)
Short-duration Insurance Contracts, Historical Claims Duration, Year Eight	0.50%
Short-duration Insurance Contracts, Historical Claims Duration, Year Nine	0.70%
Short-duration Insurance Contracts, Historical Claims Duration, Year Ten	0.10%