Employee Benefit Plans - Allocation of Plan Assets (Details)	Dec. 31, 2018	Dec. 31, 2017
U.S. equities \| U.S. Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual	35.00%	35.00%
U.S. equities \| Offshore Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual	16.00%	16.00%
Target Allocation	14.00%
Non-U.S. equities \| U.S. Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual	25.00%	25.00%
Non-U.S. equities \| Offshore Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual	46.00%	42.00%
Target Allocation	41.00%
Fixed-income securities \| U.S. Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual	35.00%	35.00%
Fixed-income securities \| Offshore Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual	9.00%	16.00%
Target Allocation	17.00%
Real estate \| U.S. Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual	5.00%	5.00%
Real estate \| Offshore Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual	8.00%	7.00%
Target Allocation	7.00%
Cash and other \| U.S. Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual	0.00%	0.00%
Cash and other \| Offshore Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual	21.00%	19.00%
Target Allocation	21.00%
Minimum \| U.S. Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation		0.00%
Minimum \| U.S. equities \| U.S. Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation		25.00%
Minimum \| Non-U.S. equities \| U.S. Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation		15.00%
Minimum \| Fixed-income securities \| U.S. Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation		15.00%
Maximum \| U.S. Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation		5.00%
Maximum \| U.S. equities \| U.S. Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation		55.00%
Maximum \| Non-U.S. equities \| U.S. Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation		45.00%
Maximum \| Fixed-income securities \| U.S. Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation		40.00%

Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=112275985&loc=d3e4179-114921

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

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Percentage of actual investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

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+ References

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