Employee benefit plans - Projected benefit obligation (Details) - Pensions Plans - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Employee benefit plans
Projected benefit obligation	$ 553	$ 605
Fair value of plan assets	$ 383	$ 425

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No definition available.

+ Details

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- Definition

Amount of plan asset for defined benefit pension plan with projected benefit obligation in excess of plan assets.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e2417-114920

+ Details

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- Definition

Amount of projected benefit obligation for defined benefit pension plan with projected benefit obligation in excess of plan assets.

+ References

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