Commitments and contingencies (Details) - USD ($) $ in Millions		1 Months Ended
	Feb. 07, 2020	Jul. 31, 2018	Mar. 27, 2020
CARES Act
Amount of single-employer funding obligation deferred to January 1, 2021			$ 15
Amount of employer portion of social security payments deferred to 2021 and 2022			$ 18
Pending Litigation | Ukranian customer
Commitments and Contingencies
Recovery amount sought		$ 227
Pending Litigation | Stockholder class action
Commitments and Contingencies
Recovery amount sought	$ 700