XML 59 R48.htm IDEA: XBRL DOCUMENT v3.19.2
Deferred Costs (Detail) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jul. 31, 2019
Jul. 31, 2018
Jul. 31, 2019
Jul. 31, 2018
Jan. 31, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]          
Deferred sales commission $ 268   $ 268   $ 264
Amortization of deferred costs $ 22 $ 17 $ 43 $ 33