Employee Benefits - Expected Rate of Return, Investment Policy, and Multiemployer Plans - Narrative (Details) $ in Millions	12 Months Ended
Dec. 31, 2016 USD ($) payment defined_contribution_plan
Asset allocation structure of the portfolio
Compound annualized risk free rate	3.50%
Expected overall portfolio return percentage	8.87%
Percentage of estimated expense	0.39%
Net long term rate of return	8.48%
Number of minimum quarterly cash contributions during fiscal 2016 and 2017 \| payment	4
Minimum required contribution for plan year, per quarter cash contributions during fiscal - 2016 \| $	$ 3.6
Percentages of employees represented by various labor unions	35.00%
Percentage of collective bargaining agreements up for renewal in 2016	10.00%
Number of defined contribution plans \| defined_contribution_plan	2
Equities
Asset allocation structure of the portfolio
Asset allocation structure of the portfolio	61.00%
Equity securities — domestic
Asset allocation structure of the portfolio
Target allocations for fiscal 2016	55.00%
Equity securities — international
Asset allocation structure of the portfolio
Target allocations for fiscal 2016	10.00%
Fixed income
Asset allocation structure of the portfolio
Asset allocation structure of the portfolio	38.00%
Target allocations for fiscal 2016	30.00%
Other
Asset allocation structure of the portfolio
Asset allocation structure of the portfolio	1.00%
Target allocations for fiscal 2016	5.00%

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No definition available.

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- Definition

Represents the estimated target allocation of investments of this type to total plan assets presented on a weighted average basis.

+ References

No definition available.

+ Details

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

Defined Contribution Plan, Number of Plans

+ References

No definition available.

+ Details

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- Definition

Represents expected overall portfolio return, percentage.

+ References

No definition available.

+ Details

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- Definition

Represents percentage of estimated expense.

+ References

No definition available.

+ Details

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- Definition

Represents net long term rate of return.

+ References

No definition available.

+ Details

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- Definition

Represents number of collective bargaining agreements up for renewal in One Year

+ References

No definition available.

+ Details

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- Definition

Represents number of minimum quarterly cash contributions during the fiscal year.

+ References

No definition available.

+ Details

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- Definition

Percentage of employees represented by various labor unions.

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Amount of employer's best estimate of contributions expected to be paid to the plan during the next fiscal year beginning after the date of the latest statement of financial position.

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

+ Details

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