Pension Plans and Other Postretirement Benefits Defined Benefit Plan Asset Target Allocation (Details) - Total Pension Benefits	12 Months Ended
Dec. 31, 2016
Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocations percentage of assets	44.00%
Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Target allocations percentage of assets	42.00%
Absolute Return
Defined Benefit Plan Disclosure [Line Items]
Target allocations percentage of assets	13.00%
Other
Defined Benefit Plan Disclosure [Line Items]
Target allocations percentage of assets	1.00%

Target allocation of investments of this type to total plan assets presented on a weighted average basis.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)(i)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e2446-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

Name:	us-gaap_DefinedBenefitPlanTargetPlanAssetAllocations
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration