Commitments and Contingencies (Unaudited) (Tables)

9 Months Ended

Sep. 30, 2017

Environmental Remediation Range of Future Costs [Line Items]

Environmental Remediation [Table Text Block]

The table below summarizes management’s estimate of the range of reasonably possible future costs for environmental remediation, the amount accrued within that range, and the deferred costs expected to be recoverable through overhead charges on U.S. Government contracts as of September 30, 2017 and December 31, 2016:

$ in millions	Range of Reasonably Possible Future Costs(1)	Accrued Costs(2)		Deferred Costs(3)
September 30, 2017	$409 - $796	$	416	$	210
December 31, 2016	379 - 774	385		195

⁽¹⁾  Estimated remediation costs are not discounted to present value. The range of reasonably possible future costs does not take into consideration amounts expected to be recoverable through overhead charges on U.S. Government contracts.

⁽²⁾ As of September 30, 2017, $144 million is recorded in other current liabilities and $272 million is recorded in other non-current liabilities.

⁽³⁾ As of September 30, 2017, $75 million is deferred in inventoried costs and $135 million is deferred in other non-current assets. These amounts are evaluated for recoverability on a routine basis.