Discontinued operations - Financial Information Balance sheet (Details) - USD ($) $ in Millions	Jul. 16, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets
Cash and cash equivalents		$ 45	$ 16
Trade and other receivables, net		168	156
Deferred tax assets		117
Property, plant and equipment		29
Intangible assets		27
Goodwill		310
Other assets		55	31
Current assets held for sale		751	203
Deferred tax assets			104
Property, plant and equipment			28
Intangible assets			28
Goodwill			296
Other assets			26
Non-current assets held for sale			482
Liabilities
Accounts payable		88	68
Accrued liabilities		18	21
Accrued compensation and benefits		21	20
Contract liabilities		29	24
Pension and other postretirement benefit liabilities		21
Other liabilities		53	21
Current liabilities held for sale		230	154
Pension and other postretirement benefit liabilities			18
Other liabilities			40
Non-current liabilities held for sale			58
Goodwill		$ 1,455	$ 1,455	$ 1,617
Neptec Design Group Ltd
Liabilities
Equity and cash consideration	$ 30
Cash paid	6
Goodwill	21
Intangible assets, net	11
Fair value of net identifiable assets acquired	$ 2