CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 1,066	$ 662
Billed receivables, net of allowances of $12 in 2018 and $18 in 2017	919	723
Contract assets	1,590	0
Contracts in process	0	1,933
Inventories	879	389
Prepaid expenses and other current assets	356	300
Assets held for sale	0	135
Assets of discontinued operations	0	306
Total current assets	4,810	4,448
Property, plant and equipment, net	1,169	1,110
Goodwill	6,808	6,615
Identifiable intangible assets	390	292
Other assets	341	264
Total assets	13,518	12,729
Current liabilities:
Accounts payable, trade	699	531
Accrued employment costs	491	493
Accrued expenses	251	217
Contract liabilities	669	0
Advance payments and billings in excess of costs incurred	0	509
Income taxes payable	49	19
Other current liabilities	288	367
Liabilities held for sale	0	17
Liabilities of discontinued operations	0	226
Total current liabilities	2,447	2,379
Pension and postretirement benefits	1,211	1,313
Deferred income taxes	196	158
Other liabilities	436	398
Long-term debt	3,321	3,330
Total liabilities	7,611	7,578
Commitments and contingencies (see Note 19)
Stockholders' Equity Attributable to Parent [Abstract]
Common stock: $.01 par value; 300,000,000 shares authorized, 78,800,714 shares outstanding at December 31, 2018 and 77,876,687 shares outstanding at December 31, 2017	6,866	6,519
Treasury stock (at cost), 84,999,711 shares at December 31, 2018 and 83,362,412 shares at December 31, 2017	(7,726)	(7,404)
Retained earnings	7,424	6,659
Accumulated other comprehensive loss	(725)	(691)
Total shareholders’ equity	5,839	5,083
Noncontrolling interests	68	68
Total equity	5,907	5,151
Total liabilities and equity	$ 13,518	$ 12,729