Segment Operating Profit (Loss) Reconciliation (Table) (Details) - USD ($) $ in Millions	3 Months Ended									12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017		Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Sales and service revenues	$ 2,199	$ 2,083	$ 2,020	$ 1,874	$ 1,996	$ 1,863	$ 1,858		$ 1,724	$ 8,176	$ 7,441	$ 7,068
Operating income (loss)	$ 213	$ 290	$ 257	$ 191	$ 231	$ 241	$ 241	[1]	$ 168	951	881	876
Ingalls [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Sales and service revenues										2,607	2,420	2,389
Operating income (loss)										313	313	321
Newport News Shipbuilding [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Sales and service revenues										4,722	4,164	4,089
Operating income (loss)										318	354	386
Technical Solutions [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Sales and service revenues										988	952	691
Operating income (loss)										32	21	8
Intersegment Eliminations [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Sales and service revenues										(141)	(95)	(101)
Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating income (loss)										663	688	715
Segment Reconciling Items [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
FAS/CAS Adjustment										290	205	163
Deferred state income taxes										$ (2)	$ (12)	$ (2)

[1] (1) In the second quarter of 2017, the Company recorded a $30 million favorable cumulative adjustment on a contract at the Ingalls segment.