XML 48 R38.htm IDEA: XBRL DOCUMENT v3.19.2
Investments (Fair Values by Classification) (Details) - USD ($)
$ in Millions
Jun. 30, 2019
Dec. 31, 2018
Fair values of available-for-sale investments by classification in the Consolidated Balance Sheets    
Cash and cash equivalents $ 5,525 $ 6,945
Marketable securities 16,233 22,359
Total interest-bearing securities 21,117 28,724
Available-for-sale investments [Member]    
Fair values of available-for-sale investments by classification in the Consolidated Balance Sheets    
Cash and cash equivalents 4,884 6,365
Marketable securities 16,233 22,359
Total interest-bearing securities $ 21,117 $ 28,724