Income taxes - Components of deferred tax assets and liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Deferred loss and tax credit carryforwards	$ 213	$ 247
Accrued expenses	113	129
Stock compensation	109	122
Inventories and related reserves	109	107
Retirement costs for defined benefit and retiree health care	49	80
Total deferred tax assets, before valuation allowance	593	685
Valuation allowance	(180)	(172)
Total deferred tax assets, after valuation allowance	413	513
Deferred tax liabilities:
Property, plant and equipment	(95)	(10)
Acquisition-related intangibles and fair-value adjustments	(82)	(142)
International earnings	(62)	(43)
Other	(55)	(65)
Total deferred tax liabilities	(294)	(260)
Net deferred tax asset	$ 119	$ 253