Quarterly report pursuant to Section 13 or 15(d)

Revenue Recognition - Narratives (Details)

v3.8.0.1
Revenue Recognition - Narratives (Details) - USD ($)
$ in Millions
Mar. 31, 2018
Dec. 31, 2017
Mar. 31, 2017
Revenue from Contract with Customer [Abstract]      
Allowance for doubtful receivables $ 12   $ 39
Contract assets 175 $ 170  
Deferred revenue 224 174  
Contract liability $ 35 $ 31