Goodwill and Other Purchased Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill [Table Text Block]

Changes in the carrying amounts of goodwill for the years ended December 31, 2017 and 2018, were as follows:

$ in millions	Aerospace Systems		Innovation Systems		Mission Systems			Technology Services			Total
Balance as of December 31, 2016	$	3,742	$	—	$	6,694		$	2,014		$	12,450
Other(1)	—		—		2			3			5
Balance as of December 31, 2017	$	3,742	$	—	$	6,696		$	2,017		$	12,455
Acquisition of Orbital ATK	418		5,256		469			79			6,222
Other(1)	—		—		(2		)	(3		)	(5		)
Balance as of December 31, 2018	$	4,160	$	5,256	$	7,163		$	2,093		$	18,672

⁽¹⁾  Other consists primarily of adjustments for foreign currency translation.

Schedule of Acquired Finite-Lived Intangible Assets by Major Class [Table Text Block]

Net customer-related and other intangible assets, including the fair value of purchased intangible assets acquired in the Merger, are as follows:

	December 31
$ in millions	2018			2017
Gross customer-related and other intangible assets	$	3,356		$	1,833
Less accumulated amortization	(1,984		)	(1,781		)
Net customer-related and other intangible assets	$	1,372		$	52

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

As of December 31, 2018, the expected future amortization of purchased intangibles for each of the next five years is as follows:

$ in millions
2019	$	331
2020	262
2021	204
2022	197
2023	78