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Pension Plans and Other Benefits - Plan Asset Fair Values (Details)	Dec. 31, 2018	Dec. 31, 2017
Canadian Equity Securities [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	18.00%	25.00%
Debt Security, Corporate, US [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	50.00%	55.00%
US and Canada Government Debt Securities [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	44.00%	42.00%
Debt Security, Corporate, Non-US [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	6.00%	3.00%
Other Foreign [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	43.00%	30.00%
U.S. Government Bonds
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	39.00%	45.00%

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- Definition

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+ References

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- Definition

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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