Commitments and Contingencies (Unaudited) (Tables)

6 Months Ended

Jun. 30, 2019

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 June 30, 2019 and December 31, 2018:

$ in millions	Range of Reasonably Possible Future Costs(1)	Accrued Costs(2)		Deferred Costs(3)
June 30, 2019	$532 - $1,018	$	547	$	426
December 31, 2018	447 - 835	461		343

⁽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 June 30, 2019, $167 million is recorded in Other current liabilities and $380 million is recorded in Other non-current liabilities.

⁽³⁾ As of June 30, 2019, $133 million is deferred in Prepaid expenses and other current assets and $293 million is deferred in Other non-current assets.