XML 57 R45.htm IDEA: XBRL DOCUMENT v3.19.1
Investments - Available-for-Sale Investments (Details)
$ in Millions
Mar. 31, 2019
USD ($)
Security
Dec. 31, 2018
USD ($)
Security
Debt Securities, Available-for-sale [Line Items]    
In a Continuous Loss Position for Less than 12 Months, Estimated Fair Value $ 207 $ 509
In a Continuous Loss Position for Less than 12 Months, Unrealized Losses $ 1 $ 3
In a Continuous Loss Position for Less than 12 Months, Number of Positions (in security) | Security 96 285
In a Continuous Loss Position for 12 Months or More, Estimated Fair value $ 612 $ 694
In a Continuous Loss Position for 12 Months or More, Unrealized Losses $ 4 $ 8
In a Continuous Loss Position for 12 Months or More, Number of Positions (in security) | Security 442 516
Corporate debt securities    
Debt Securities, Available-for-sale [Line Items]    
In a Continuous Loss Position for Less than 12 Months, Estimated Fair Value $ 207 $ 509
In a Continuous Loss Position for Less than 12 Months, Unrealized Losses $ 1 $ 3
In a Continuous Loss Position for Less than 12 Months, Number of Positions (in security) | Security 96 285
In a Continuous Loss Position for 12 Months or More, Estimated Fair value $ 403 $ 412
In a Continuous Loss Position for 12 Months or More, Unrealized Losses $ 2 $ 5
In a Continuous Loss Position for 12 Months or More, Number of Positions (in security) | Security 280 298
GSEs    
Debt Securities, Available-for-sale [Line Items]    
In a Continuous Loss Position for Less than 12 Months, Estimated Fair Value $ 0 $ 0
In a Continuous Loss Position for Less than 12 Months, Unrealized Losses $ 0 $ 0
In a Continuous Loss Position for Less than 12 Months, Number of Positions (in security) | Security 0 0
In a Continuous Loss Position for 12 Months or More, Estimated Fair value $ 122 $ 127
In a Continuous Loss Position for 12 Months or More, Unrealized Losses $ 1 $ 1
In a Continuous Loss Position for 12 Months or More, Number of Positions (in security) | Security 71 76
Municipal securities    
Debt Securities, Available-for-sale [Line Items]    
In a Continuous Loss Position for Less than 12 Months, Estimated Fair Value $ 0 $ 0
In a Continuous Loss Position for Less than 12 Months, Unrealized Losses $ 0 $ 0
In a Continuous Loss Position for Less than 12 Months, Number of Positions (in security) | Security 0 0
In a Continuous Loss Position for 12 Months or More, Estimated Fair value $ 87 $ 87
In a Continuous Loss Position for 12 Months or More, Unrealized Losses $ 1 $ 1
In a Continuous Loss Position for 12 Months or More, Number of Positions (in security) | Security 91 90
Asset-backed securities    
Debt Securities, Available-for-sale [Line Items]    
In a Continuous Loss Position for Less than 12 Months, Estimated Fair Value   $ 0
In a Continuous Loss Position for Less than 12 Months, Unrealized Losses   $ 0
In a Continuous Loss Position for Less than 12 Months, Number of Positions (in security) | Security   0
In a Continuous Loss Position for 12 Months or More, Estimated Fair value   $ 68
In a Continuous Loss Position for 12 Months or More, Unrealized Losses   $ 1
In a Continuous Loss Position for 12 Months or More, Number of Positions (in security) | Security   52