Acquisition of Orbital ATK Acquisition of Orbital ATK (Details 3) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
	Jun. 06, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Shares, Outstanding	57,562,152
Business Acquisition, Share Price	$ 134.50
Business Combination, Consideration Transferred	$ 7,742
Goodwill		$ 18,672	$ 12,455	$ 12,450
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		12 years
Business Combination, Below Market Contracts, reduction in sales for 2018	64
Business Combination, Below Market Contracts, reduction in sales for 2019	45
Business Combination, Below Market Contracts, reduction in sales for 2020	2
Orbital ATK [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	85
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables	596
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Unbilled Receivables	1,264
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory	220
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets	214
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	1,509
Goodwill	6,222
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	1,525
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	151
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	11,786
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable	397
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Employee-related liabilities	158
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Customer Advances	222
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Below Market Contracts	151
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other	412
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt	1,687
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, NonCurrent Liabilities, Defined Benefit Plan Liability	613
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities	248
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other	156
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	4,044
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	7,742
Customer Relationships [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	$ 280
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	13 years
Customer Contracts [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	$ 1,245
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	9 years