Fair Value Measurements (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014
National Pump
Derivatives, Fair Value [Line Items]
Contingent consideration	$ 76
Discount rate	2.90%
Level 3 \| National Pump \| Accrued expenses and other liabilities
Derivatives, Fair Value [Line Items]
Contingent consideration	78
Contingent consideration \| National Pump
Derivatives, Fair Value [Line Items]
Discount rate	11.00%
Contingent consideration, payment one \| National Pump
Derivatives, Fair Value [Line Items]
Contingent consideration	70
Contingent consideration, payment two \| National Pump
Derivatives, Fair Value [Line Items]
Contingent consideration	8
Merger related costs
Derivatives, Fair Value [Line Items]
Change in contingent consideration	$ 2
Diesel swap \| Swap
Derivatives, Fair Value [Line Items]
Derivative, nonmonetary notional amount (in gallons)	5,400,000
Derivative, notional amount (in dollars per gallon)	3.64
Average forward price (in dollars per gallon)	2.97

Amount of increase (decrease) in the value of a contingent consideration liability, including, but not limited to, differences arising upon settlement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 50

-Paragraph 4

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e7008-128479

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- Definition

Amount of liability recognized arising from contingent consideration in a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 25

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6408-128476

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-Section 35

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The average forward price on the group of price risk forward or futures contracts, such as gas futures contracts.

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- Definition

Nominal volume used to calculate payments on a derivative instrument.

+ References

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Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

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Specified interest rate, security price, commodity price, foreign exchange rate, index of prices or rates for a derivative contract measured in volume but not the derivative contract itself.

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