Stock-based compensation plans - Share Appreciation Rights (Details) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2020 USD ($) employee $ / shares shares	Dec. 31, 2020 $ / shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 $ / shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 shares	Dec. 31, 2020 USD ($)
Additional disclosures
Incremental Expense | $	$ 3
Number of employees affected due to modification of settlement | employee	37
Omnibus Plan
Number of Awards
Granted (in shares)				0
Share Appreciation Rights | Pre 2017 LTIP
Additional disclosures
Vesting period			3 years
Vesting percentage			33.33%
Share Appreciation Rights | 2017 LTIP
Additional disclosures
Vesting period			4 years
Vesting percentage			25.00%
Share Appreciation Rights | Omnibus Plan
Additional disclosures
Vesting period			4 years
Vesting percentage			25.00%
SARs Liability Classified Awards
Number of Awards
Outstanding at the beginning of the period (in shares)			579,320
Granted (in shares)			0	0
Exercised (in shares)			0	0
Cancelled or expired (in shares)			(197,100)
Outstanding at the end of the period (in shares)	382,220		382,220	579,320
Vested and expected to vest at the end of the period			382,220
Exercisable at the end of the period			381,470
Weighted Average Exercise Price
Outstanding at the beginning of the period (per share) | $ / shares		$ 63.12
Cancelled or expired (per share) | $ / shares		67.92
Outstanding at the end of the period (per share) | $ / shares		60.65
Vested and expected to vest at the end of the period | $ / shares		60.65
Exercisable at the end of the period | $ / shares		60.68
Contractual Term (in years)
Outstanding at the end of the period			1 year 1 month 2 days
Vested and expected to vest at the end of the period			1 year 1 month 2 days
Exercisable at the end of the period			1 year 29 days
SARs Accounted for as Equity Classified Awards
Number of Awards
Outstanding at the beginning of the period (in shares)			925,591
Granted (in shares)			0	0
Exercised (in shares)			0	0
Cancelled or expired (in shares)			(115,064)
Outstanding at the end of the period (in shares)	810,527		810,527	925,591
Vested and expected to vest at the end of the period			810,527
Exercisable at the end of the period			713,859
Weighted Average Exercise Price
Outstanding at the beginning of the period (per share) | $ / shares		51.18
Cancelled or expired (per share) | $ / shares		50.67
Outstanding at the end of the period (per share) | $ / shares		51.25
Vested and expected to vest at the end of the period | $ / shares		51.25
Exercisable at the end of the period | $ / shares		$ 50.95
Contractual Term (in years)
Outstanding at the end of the period			6 years 3 months 25 days
Vested and expected to vest at the end of the period			6 years 3 months 25 days
Exercisable at the end of the period			6 years 3 months
Weighted Average Grant Date Fair Value
Granted (per share) | $ / shares					$ 10.37
Restricted Share Units
Number of Awards
Outstanding at the beginning of the period (in shares)			986,735
Granted (in shares)			2,083,425
Vested (in shares)			(409,551)
Modified (in shares)			532,365
Cancelled or expired (in shares)			(243,005)
Outstanding at the end of the period (in shares)	2,949,969		2,949,969	986,735
Weighted Average Grant Date Fair Value
Outstanding at the beginning of the period (per share) | $ / shares			$ 7.91
Granted (per share) | $ / shares			13.57
Vested (per share) | $ / shares			7.75
Cancelled or expired (per share) | $ / shares			12.22
Modified (per share) | $ / shares			28.74
Outstanding at the end of the period (per share) | $ / shares	$ 15.33		$ 15.33	$ 7.91
Additional disclosures
Vesting period			3 years
Restricted Share Units | Omnibus and DigitalGlobe Equity Incentive Plan
Number of Awards
Vested (in shares)			(640,657)
Weighted Average Grant Date Fair Value
Total fair value of vested awards | $			$ 14	$ 14		$ 19
Additional disclosures
Total unrecognized compensation expense | $								$ 19
Weighted average remaining period (in years)			1 year 1 month 6 days
Restricted Share Units | Omnibus Plan
Number of Awards
Outstanding at the beginning of the period (in shares)			247,498
Vested (in shares)			(159,679)
Cancelled or expired (in shares)			(17,446)
Outstanding at the end of the period (in shares)	70,373		70,373	247,498
Weighted Average Grant Date Fair Value
Outstanding at the beginning of the period (per share) | $ / shares			$ 36.42
Vested (per share) | $ / shares			45.69
Cancelled or expired (per share) | $ / shares			48.45
Outstanding at the end of the period (per share) | $ / shares	$ 12.41		$ 12.41	$ 36.42
Additional disclosures
Vesting percentage						33.33%
Restricted Share Units | DigitalGlobe Equity Plan
Number of Awards
Outstanding at the beginning of the period (in shares)			100,671
Granted (in shares)							0
Vested (in shares)			(71,427)
Cancelled or expired (in shares)			(2,928)
Outstanding at the end of the period (in shares)	26,316		26,316	100,671
Weighted Average Grant Date Fair Value
Outstanding at the beginning of the period (per share) | $ / shares			$ 54.57
Vested (per share) | $ / shares			54.57
Cancelled or expired (per share) | $ / shares			54.57
Outstanding at the end of the period (per share) | $ / shares	$ 54.57		$ 54.57	$ 54.57
RSUs Liability Classified Awards
Number of Awards
Outstanding at the beginning of the period (in shares)			946,281
Vested (in shares)			(291,989)	0		0
Modified (in shares)	(532,365)		(532,365)
Cancelled or expired (in shares)			(121,927)
Outstanding at the end of the period (in shares)	0		0	946,281
Weighted Average Grant Date Fair Value
Outstanding at the beginning of the period (per share) | $ / shares			$ 6.93
Vested (per share) | $ / shares			6.93
Cancelled or expired (per share) | $ / shares			6.92
Modified (per share) | $ / shares			$ 6.93
Outstanding at the end of the period (per share) | $ / shares				$ 6.93
Additional disclosures
Cash paid to settle liability classified awards | $			$ 4