Commitments and Contingencies (Unaudited) (Tables)

3 Months Ended

Mar. 31, 2021

Environmental Remediation Range of Future Costs [Line Items]

Environmental Remediation [Table Text Block]

The table below summarizes the amount accrued for environmental remediation costs, management’s estimate of the amount of reasonably possible future costs in excess of accrued costs and the deferred costs expected to be recoverable through overhead charges on U.S. government contracts as of March 31, 2021 and December 31, 2020:

$ in millions	Accrued Costs(1)(2)		Reasonably Possible Future Costs in Excess of Accrued Costs(2)		Deferred Costs(3)
March 31, 2021	$	621	$	342	$	534
December 31, 2020	614		346		529

(1) As of March 31, 2021, $246 million is recorded in Other current liabilities and $375 million is recorded in Other non-current liabilities.

(2) Estimated remediation costs are not discounted to present value. The reasonably possible future costs in excess of accrued costs do not take into consideration amounts expected to be recoverable through overhead charges on U.S. government contracts.

(3) As of March 31, 2021, $218 million is deferred in Prepaid expenses and other current assets and $316 million is deferred in Other non-current assets. These amounts are evaluated for recoverability on a routine basis.