XML 116 R62.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Accounting changes and new accounting guidance - Narrative (Details) - USD ($)
$ in Millions
Dec. 31, 2019
Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Operating lease, right-of-use asset $ 1,530  
Operating lease, liability $ 1,772  
ASU 2016-02    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Operating lease, right-of-use asset   $ 1,300
Operating lease, liability   1,500
Retained earnings | ASU 2018-02    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Adjustment for the cumulative effect of applying the ASU   90
Accumulated other comprehensive (loss), net of tax | ASU 2018-02    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Adjustment for the cumulative effect of applying the ASU   $ (90)