Income Taxes, Components of Net Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets [Abstract]
Inventoried costs	$ 47	$ 44
Compensation and benefits	90	94
Pension and postretirement benefits	271	281
Loss carryforwards	13	12
Tax credit carryforwards	4	5
Other	67	57
Deferred tax assets	492	493
Less: valuation allowance	(14)	(10)
Deferred tax assets, net of valuation allowance	478	483
Deferred tax liabilities [Abstract]
Goodwill and other intangible assets	(549)	(514)
Income recognition on contracts in process	(18)	(24)
Property, plant and equipment	(66)	(59)
Other	(36)	(41)
Deferred tax liabilities	(669)	(638)
Total deferred tax liabilities, net of valuation allowance	$ (191)	$ (155)