Postretirement Benefit Plans - Weighted-Average Assumptions used to Determine Benefit Obligations (Detail)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cost Assumptions:
Expected return on plan assets	6.00%	7.00%	7.20%
Other Postretirement Benefits Plan [Member]
Obligation Assumptions:
Discount rate	4.30%	3.60%
Cost Assumptions:
Discount rate	3.60%	4.10%
Expected return on plan assets	6.00%	7.00%
U.S. Plan [Member] \| Pension Plan [Member]
Obligation Assumptions:
Discount rate	4.30%	3.60%
Cost Assumptions:
Discount rate	3.60%	4.20%
Expected return on plan assets	6.00%	7.00%
International Plan [Member] \| Pension Plan [Member]
Obligation Assumptions:
Discount rate	1.70%	1.70%
Rate of future compensation increase	3.20%	3.30%
Cost Assumptions:
Discount rate	1.70%	1.70%
Expected return on plan assets	1.00%	1.00%

Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(1)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

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- Definition

Weighted average rate increase of compensation, used to determine benefit obligation of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(2)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

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- Definition

Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan.

+ References

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- Definition

Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(3)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

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