Leases Capital Lease Disclosures (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Capital Leased Assets [Line Items]
Description of lessee leasing arrangements, capital leases	Under certain capital-lease agreements, Con-way guarantees the residual value of tractors at the end of the lease term. The stated amounts of the residual-value guarantees have been included in the minimum lease payments below.
Accumulated depreciation related to capital leases	$ 50.1	$ 39.0
Revenue Equipment [Member]
Capital Leased Assets [Line Items]
Capital leased assets, gross	73.3	68.9
Other equipment [Member]
Capital Leased Assets [Line Items]
Capital leased assets, gross	10.0
Accumulated depreciation related to capital leases	$ 1.5

Amount before accumulated depreciation of leased physical assets used in the normal conduct of business to produce goods and services.

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The total charge for the use of long-lived depreciable assets subject to a lease meeting the criteria for capitalization.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 30

-Section 45

-Paragraph 1

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 10

-Section 55

-Paragraph 40

-Subparagraph (Note 2)

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- Definition

A general description of the lessee's leasing arrangements including, but not limited to, the following: a) the basis on which contingent rental payments are determined; (b) the existence and terms of renewal or purchase options and escalation clauses; (c) restrictions imposed by lease agreements, such as those concerning dividends, additional debt, and further leasing.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6452660&loc=d3e36991-112694

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

-Publisher FASB

-Name Accounting Standards Codification

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-Section 25

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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