Receivables, Net (Tables)
 12 Months Ended
Dec. 31, 2018
Contracts Receivable [Abstract]  
Schedule of Receivables, Net Receivables, net, consisted of the following at December 31: 
(In millions)
2018

 
2017

U.S. government contracts (including foreign military sales)
$
1,121

 
$
881

Other customers
539

 
451

Allowance for doubtful accounts
(12
)
 
(8
)
Total receivables, net
$
1,648

 
$
1,324