Changes in Operations (Details 5) In Thousands, unless otherwise specified	Sep. 01, 2011 AZER [Member] USD ($)	Dec. 31, 2011 FreightLink [Member] USD ($)	Dec. 01, 2010 FreightLink [Member] USD ($)	Dec. 01, 2010 FreightLink [Member] AUD
Business Acquisition [Line Items]
Accounts receivable, net	$ 3,096		$ 155	161
Materials and supplies			3,209	3,328
Prepaid expense and other	2,319		97	101
Property and equipment	90,129		319,311	331,201
Total assets	95,544		322,772	334,791
Accounts payable	1,794
Accrued expenses	3,418		705	731
Long-term debt		2,000	1,741	1,806
Deferred income tax liability			307	318
Net assets	90,332
Net assets			$ 320,019	331,936

Amount of cash paid to acquire the entity.

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The amount of acquisition cost of a business combination allocated to assets acquired.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141

-Paragraph 37

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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The total purchase price of the acquired entity. This includes cash paid to equity interest holders of the acquired entity, fair value of debt and equity securities issued to equity holders of the acquired entity, and transaction costs paid to third parties to consummate the acquisition.

+ References

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The amount of acquisition cost of a business combination allocated to prepaid expenses and other current assets. Does not include amounts allocated to cash and cash equivalents, marketable securities, receivables, inventory, and assets not to be used.

+ References

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- Definition

The amount of acquisition cost of a business combination allocated to raw materials inventory.

+ References

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The amount of acquisition cost of a business combination allocated to receivables.

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The amount of acquisition cost of a business combination allocated to accounts payable of the acquired entity.

+ References

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The amount of acquisition cost of a business combination allocated to accrued expenses of the acquired entity.

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- Definition

Amount of deferred tax assets or liabilities for the differences between the values assigned and the tax bases of assets and liabilities in a business combination, net of any valuation allowance for deferred tax assets.

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- Definition

The amount of acquisition cost of a business combination allocated to the noncurrent portion of the long-term debt assumed from the acquired entity.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141

-Paragraph 51

-Subparagraph e

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 98-1

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141

-Paragraph 37

-Subparagraph g

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

The amount of acquisition cost of a business combination allocated to property, plant and equipment to be used in ongoing operations.

+ References

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