Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 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 December 31, 2017 and 2016:



$ in millions	Range of Reasonably Possible Future Costs⁽¹⁾	Accrued Costs⁽²⁾		Deferred Costs⁽³⁾
December 31, 2017	$405 - $792	$	410	$	207
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 December 31, 2017, $148 million is recorded in other current liabilities and $262 million is recorded in other non-current liabilities.


⁽³⁾	As of December 31, 2017, $76 million is deferred in inventoried costs and $131 million is deferred in other non-current assets. These amounts are evaluated for recoverability on a routine basis.

Schedule of Future Minimum Rental Payments for Operating Leases

Minimum rental commitments under long-term non-cancelable operating leases as of December 31, 2017 are payable as follows:



$ in millions
Year Ending December 31
2018	$	232
2019	195
2020	145
2021	120
2022	87
Thereafter	559
Total minimum lease payments	$	1,338