v3.8.0.1
Fair Value of Assets and Liabilities (Changes in Fair Values Recorded in Earnings for FVO Assets-Liabilities (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Fair Value, Option, Quantitative Disclosures [Line Items]      
Interest expense $ 1,327 $ 1,320 $ 1,306
Commercial mortgage and other loans [1] 56,045 52,779  
Other long-term investments [1] 12,308 11,283  
Commercial mortgage and other loans      
Fair Value, Option, Quantitative Disclosures [Line Items]      
Changes in instrument-specific credit risk 0 0 0
Changes in fair value 0 0 0
Interest Income 13 10 11
Fair value option loans in nonaccrual status 0    
Fair value option loans in more than 90 days past due and still accruing 0    
Other long-term investments      
Fair Value, Option, Quantitative Disclosures [Line Items]      
Changes in fair value 147 58 2
Notes issued by consolidated VIEs      
Fair Value, Option, Quantitative Disclosures [Line Items]      
Changes in fair value 4 37 (434)
Interest expense 75 120 $ 351
Fair value option      
Fair Value, Option, Quantitative Disclosures [Line Items]      
Commercial mortgage and other loans 593 519  
Other long-term investments 1,945 1,556  
Notes issued by consolidated VIEs 1,196 1,839  
Fair value option, aggregate contractual principal      
Fair Value, Option, Quantitative Disclosures [Line Items]      
Commercial mortgage and other loans 582 508  
Notes issued by consolidated VIEs $ 1,233 $ 1,886  
[1] See Note 5 for details of balances associated with variable interest entities.