Update
Apparently, moment now provides its own type definitions (according to sivabudh at least from 2.14.1 upwards), thus you do not need typings or @types at all.
import * as moment from 'moment' should load the type definitions provided with the npm package.
That said however, as said in moment/pull/3319#issuecomment-263752265 the moment team seems to have some issues in maintaining those definitions (they are still searching someone who maintains them).
You need to install moment typings without the --ambient flag.
Then include it using import * as moment from 'moment'