Segment information - Capital expenditures (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment information
Capital expenditures, property, plant and equipment	$ 59	$ 43
Capital expenditures, intangible assets	14	17
Capital expenditures	73	60
Operating Segments | Space Systems
Segment information
Capital expenditures, property, plant and equipment	6	5
Capital expenditures, intangible assets	1
Capital expenditures	7	5
Operating Segments | Imagery
Segment information
Capital expenditures, property, plant and equipment	50	38
Capital expenditures, intangible assets	13	17
Capital expenditures	63	$ 55
Intersegment eliminations
Segment information
Capital expenditures, property, plant and equipment	3
Capital expenditures	$ 3