Benefit Plans, Allocation of Plan Assets (Details)	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015
Retirement Plan [Member]
Major categories of pension and postretirement benefit plan assets [Abstract]
Total asset allocation	100.00%	100.00%
Retirement Plan [Member] \| Equity Securities [Member]
Major categories of pension and postretirement benefit plan assets [Abstract]
Total asset allocation	64.00%	60.00%
Retirement Plan [Member] \| Debt Securities [Member]
Major categories of pension and postretirement benefit plan assets [Abstract]
Total asset allocation	31.00%	32.00%
Retirement Plan [Member] \| Other [Member]
Major categories of pension and postretirement benefit plan assets [Abstract]
Total asset allocation	5.00%	8.00%
Post-Retirement Benefits Plan [Member]
Major categories of pension and postretirement benefit plan assets [Abstract]
Total asset allocation	100.00%	100.00%
Post-Retirement Benefits Plan [Member] \| Equity Securities [Member]
Major categories of pension and postretirement benefit plan assets [Abstract]
Total asset allocation	62.00%	60.00%
Post-Retirement Benefits Plan [Member] \| Debt Securities [Member]
Major categories of pension and postretirement benefit plan assets [Abstract]
Total asset allocation	33.00%	25.00%
Post-Retirement Benefits Plan [Member] \| Other [Member]
Major categories of pension and postretirement benefit plan assets [Abstract]
Total asset allocation	6.00%	15.00%
Pension and Postretirement Plans [Member] \| Equity Securities [Member]
Assets target allocations [Abstract]
Prescribed target allocations range, minimum	50.00%
Prescribed target allocation range, maximum	70.00%
Pension and Postretirement Plans [Member] \| Debt Securities [Member]
Assets target allocations [Abstract]
Prescribed target allocations range, minimum	25.00%
Prescribed target allocation range, maximum	40.00%
Pension and Postretirement Plans [Member] \| Other [Member]
Assets target allocations [Abstract]
Prescribed target allocations range, minimum	0.00%
Prescribed target allocation range, maximum	10.00%

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- References

No definition available.

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- Definition

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

+ References

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

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- Definition

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

+ References

Reference 1: 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

Reference 2: 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

+ Details

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- Definition

Percentage of fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of plan assets held.

+ References

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)
-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)(1)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

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