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Pension Plans and Other Benefits - Plan Asset Fair Values (Details) | Dec. 31, 2018 | Dec. 31, 2017
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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 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 + Details
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