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Employee Benefit Plans (Details 2) - item	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Weighted-average assumptions used to determine benefit obligations
Discount rate (as a percent)		3.50%
Weighted-average assumptions used to determine net periodic benefit costs
Discount rate (as a percent)		4.90%	4.00%
Long-term rate of return on assets (as a percent)	4.00%	6.00%	6.00%
Guidelines regarding allocation of assets
Number of companies or government agencies in which the allocation of assets should not exceed 10% of the total fund	1
Maximum allocation of assets in the securities of any one company or government agency (as a percent)	10.00%
Maximum allocation of assets in any one industry (as a percent)	20.00%
Number of industries in which the allocation of assets should be no more than 20% of the total fund	1
Individual treasury securities (as a percent)	50.00%
Treasury bonds and notes, maximum (as a percent)	100.00%
Employee Benefit Plans
Total (as a percent)		100.00%
Equity securities
Employee Benefit Plans
Total (as a percent)		4.20%
Debt securities
Employee Benefit Plans
Total (as a percent)		94.00%
Other investments
Employee Benefit Plans
Total (as a percent)		1.80%
Fixed income securities
Employee Benefit Plans
Total (as a percent)		95.00%
Equity securities and other investments
Employee Benefit Plans
Total (as a percent)		5.00%

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- References

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The interest rate used to adjust for the time value of money for the plan.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(1)
-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

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The interest rate used to adjust for the time value of money.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(1)
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An assumption as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Expected Long-Term Rate of Return on Plan Assets
-URI http://asc.fasb.org/extlink&oid=6512046

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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.

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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=58740216&loc=d3e2446-114920

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Represents the target allocation maximum percentage of investments in the securities of any one company or government agency to total plan assets.

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Represents the target allocation percentage of investments in individual treasury securities to total plan assets.

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Represents the target allocation maximum percentage of investments in treasury bonds and notes to total plan assets.

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Represents the number of companies or government agencies in which the allocation of plan assets should not exceed the specified threshold percentage of the total fund.

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Represents the number of industries in which the allocation of plan assets should not exceed the specified threshold percentage of the total fund.

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