Knight-Swift Transportation (KNX) 10-K 20 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Jun. 30, 2014	Feb. 13, 2015
Entity Information [Line Items]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	SWFT
Entity Registrant Name	SWIFT TRANSPORTATION Co
Entity Central Index Key	1492691
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Entity Public Float		$2,216,403,173
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Class A Common Stock [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding			91,129,162
Class B Common Stock [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding			50,991,938

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$105,132		$59,178
Restricted cash	45,621		50,833
Restricted investments, held to maturity, amortized cost	24,510		25,814
Accounts receivable, net	478,999		418,436
Equipment sales receivable	288		368
Income tax refund receivable	18,455		23,704
Inventories and supplies	18,992		18,430
Assets held for sale	2,907		19,268
Prepaid taxes, licenses, insurance and other	51,441		63,958
Deferred income taxes	44,861		46,833
Current portion of notes receivable	9,202		7,210
Total current assets	800,408		734,032
Property and equipment, at cost:
Revenue and service equipment	2,061,835		1,942,423
Land	122,835		117,929
Facilities and improvements	268,025		248,724
Furniture and office equipment	67,740		61,396
Total property and equipment	2,520,435		2,370,472
Less: accumulated depreciation and amortization	978,305		922,665
Net property and equipment	1,542,130		1,447,807
Other assets	41,855		57,166
Intangible assets, net	299,933		316,747
Goodwill	253,256		253,256
Total assets	2,937,582		2,809,008
Current liabilities:
Accounts payable	160,186		118,014
Accrued liabilities	100,329		110,745
Current portion of claims accruals	81,251		75,469
Long-term Debt, Current Maturities	31,445		11,387
Capital Lease Obligations, Current	42,902		63,669
Fair value of guarantees	0		366
Current portion of fair value of interest rate swaps	6,109		4,718
Total current liabilities	422,222		384,368
Revolving line of credit	57,000	[1]	17,000	[1]
Long-term debt, less current portion	871,615		1,138,918
Capital lease obligations, long-term	158,104		107,846
Claims accruals, less current portion	143,693		118,582
Fair value of interest rate swaps, less current portion	0		7,050
Deferred income taxes	480,640		484,200
Transfers Accounted for as Secured Borrowings, Associated Liabilities, Carrying Amount	334,000		264,000
Other liabilities	14		3,457
Total liabilities	2,467,288		2,525,421
Commitments and contingencies (notes 13, 14 and 15)
Stockholders’ equity:
Preferred stock, par value $0.01 per share; Authorized 10,000,000 shares; none issued	0		0
Additional paid-in capital	781,124		759,408
Accumulated deficit	-310,017		-471,169
Accumulated other comprehensive loss	-2,336		-6,162
Noncontrolling interest	102		102
Total stockholders’ equity	470,294		283,587
Total liabilities and stockholders’ equity	2,937,582		2,809,008
Class A Common Stock [Member]
Stockholders’ equity:
Common stock, value	911		883
Class B Common Stock [Member]
Stockholders’ equity:
Common stock, value	$510		$525
[1]	(1)In addition to borrowings, the Company also had outstanding letters of credit of $100.3 million under the $450.0 million Revolver at December 31, 2014 and $108.5 million under the $400.0 million Revolver at December 31, 2013, primarily related to workers' compensation and self-insurance liabilities.

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares Authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Class A Common Stock [Member]
Common stock, par value	$0.01	$0.01
Common stock, shares Authorized	500,000,000	500,000,000
Common stock, shares issued	91,103,643	88,402,991
Common stock, shares outstanding	91,103,643	88,402,991
Class B Common Stock [Member]
Common stock, par value	$0.01	$0.01
Common stock, shares Authorized	250,000,000	250,000,000
Common stock, shares issued	50,991,938	52,441,938
Common stock, shares outstanding	50,991,938	52,441,938

Consolidated_Statements_Of_Ope

Consolidated Statements Of Operations (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Operating revenue	$4,298,724	$4,118,195	$3,976,085
Operating expenses:
Salaries, wages and employee benefits	970,683	903,990	879,856
Operating supplies and expenses	342,073	319,023	290,472
Fuel	591,855	640,000	668,707
Purchased transportation	1,321,268	1,255,646	1,195,033
Rental expense	229,290	180,328	149,433
Insurance and claims	159,246	142,179	121,655
Cost of Services, Depreciation and Amortization	221,122	226,008	218,839
Amortization of intangibles	16,814	16,814	16,925
Impairments	2,308	0	3,387
Gain on disposal of property and equipment	-27,682	-22,664	-18,351
Communication and utilities	29,871	25,593	26,464
Direct Taxes and Licenses Costs	71,806	74,319	71,849
Total operating expenses	3,928,654	3,761,236	3,624,269
Operating income	370,070	356,959	351,816
Other (income) expenses:
Interest expense	80,064	99,534	122,049
Derivative interest expense	6,495	3,852	5,101
Interest income	-2,909	-2,474	-2,156
Merger and acquisition expense	0	4,913	0
Gains (Losses) on Extinguishment of Debt, before Write off of Deferred Debt Issuance Cost	-39,909	-5,540	-22,219
Impairments on non-operating assets	0	0	5,979
Gain on sale of real property	0	-6,876	0
Other	-4,115	-3,934	-3,077
Total other (income) expenses, net	119,444	100,555	150,115
Income before income taxes	250,626	256,404	201,701
Income tax expense	89,474	100,982	61,614
Net income	$161,152	$155,422	$140,087
Net income
Basic earnings per share	$1.14	$1.11	$1
Diluted earnings per share	$1.12	$1.09	$1
Shares used in per share calculations
Basic (in shares)	141,431	140,179	139,532
Diluted (in shares)	143,475	142,221	139,619

Consolidated_Statements_Of_Com

Consolidated Statements Of Comprehensive Income (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement Of Comprehensive Income [Abstract]
Net income	$161,152	$155,422	$140,087
Other comprehensive income before income taxes:
Accumulated losses on derivatives reclassified to derivative interest expense	6,218	3,143	5,101
Change in fair value of interest rate swaps	0	-145	-2,786
Other comprehensive income before income taxes	6,218	2,998	2,315
Income tax effect of items of other comprehensive income	-2,392	-958	1,142
Other comprehensive income, net of taxes	3,826	2,040	3,457
Total comprehensive income	$164,978	$157,462	$143,544

Consolidated_Statements_Of_Sto

Consolidated Statements Of Stockholders' Equity (USD $)	Total	Central Refrigerated Service, Inc. [Member]	Common Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interest [Member]	Central Refrigerated Stockholders' Loans Receivable, Pre-Acquisition [Member]
			Class A Common Stock [Member]	Class B Common Stock [Member]		Central Refrigerated Service, Inc. [Member]
Beginning balance at Dec. 31, 2011	$155,186,000		$859,000	$536,000	$915,696,000		($728,259,000)	($11,659,000)	$102,000	($22,089,000)
Beginning balance, shares at Dec. 31, 2011			85,935,116	53,563,460
Grant of restricted Class A common stock	4,000				4,000
Grant of restricted Class A common stock, shares			11,676
Exercise of stock options	268,000				268,000
Exercise of stock options, shares			24,427
Excess tax deficiency of stock options	-370,000				-370,000
Exercise of stock options and tax deficiency, shares	24,427,000
Conversion of Class B common stock to Class A common stock	0		11,000	-11,000
Conversion of Class B common stock to Class A common stock, shares			-1,068,224	-1,068,224
Shares issued under employee stock purchase plan	134,000		1,000		133,000
Shares issued under employee stock purchase plan, shares			16,221
Other comprehensive income, net	3,457,000							3,457,000
Non-cash equity compensation	4,886,000				4,886,000
Central non-cash exercise of stock options	210,000				210,000
Distribution to Central stockholders, pre-acquisition	-13,605,000						-13,605,000
Interest on Central stockholders' loans receivable, pre-acquisition	-53,000									-53,000
Net income	140,087,000						140,087,000
Ending balance at Dec. 31, 2012	290,204,000		871,000	525,000	920,827,000		-601,777,000	-8,202,000	102,000	-22,142,000
Ending balance, shares at Dec. 31, 2012			87,055,664	52,495,236
Grant of restricted Class A common stock	86,000				86,000
Grant of restricted Class A common stock, shares			10,480
Exercise of stock options	12,985,000		12,000		12,973,000
Exercise of stock options, shares			1,210,184
Excess tax deficiency of stock options	187,000				187,000
Exercise of stock options and tax deficiency, shares	1,210,184,000
Conversion of Class B common stock to Class A common stock	0
Conversion of Class B common stock to Class A common stock, shares			-53,298	-53,298
Shares issued under employee stock purchase plan	960,000				960,000
Shares issued under employee stock purchase plan, shares			73,365
Other comprehensive income, net	2,040,000							2,040,000
Non-cash equity compensation	3,670,000	887,000			3,670,000	887,000
Central non-cash exercise of stock options	0				3,415,000					-3,415,000
Issuance of Central stockholders' loan receivable, pre-acquisition	-30,000,000									-30,000,000
Net settlements of distribution to Central stockholders in satisfaction of stockholders' loans receivable, pre-acquisition	0						-22,315,000			22,315,000
Distribution to Central stockholders, pre-acquisition	-2,499,000				-2,499,000
Interest on Central stockholders' loans receivable, pre-acquisition	-53,000									-53,000
Acquisition of Central, a common control entity, net of repayment of stockholders' loans receivable at closing of acquisition	-150,302,000				-183,597,000					33,295,000
Net income	155,422,000						155,422,000
Ending balance at Dec. 31, 2013	283,587,000		883,000	525,000	759,408,000		-471,169,000	-6,162,000	102,000	0
Ending balance, shares at Dec. 31, 2013			88,402,991	52,441,938
Grant of restricted Class A common stock	315,000				314,000
Grant of restricted Class A common stock, shares			98,866
Stock Issued During Period, Value, New Issues			1,000
Exercise of stock options	11,488,000		11,000		11,477,000
Exercise of stock options, shares	1,100,998		1,100,998
Excess tax deficiency of stock options	3,730,000				3,730,000
Exercise of stock options and tax deficiency, shares	1,100,998,000
Conversion of Class B common stock to Class A common stock	0		15,000	-15,000
Conversion of Class B common stock to Class A common stock, shares			-1,450,000	-1,450,000
Shares issued under employee stock purchase plan	1,116,000		1,000		1,115,000
Shares issued under employee stock purchase plan, shares			50,788
Other comprehensive income, net	3,826,000							3,826,000
Non-cash equity compensation	5,080,000				5,080,000
Net income	161,152,000						161,152,000
Ending balance at Dec. 31, 2014	$470,294,000		$911,000	$510,000	$781,124,000		($310,017,000)	($2,336,000)	$102,000	$0
Ending balance, shares at Dec. 31, 2014			91,103,643	50,991,938

Consolidated_Statements_Of_Cas

Consolidated Statements Of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net income	$161,152	$155,422	$140,087
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property, equipment and intangibles	237,936	242,822	235,764
Amortization of debt issuance costs, original issue discount, and losses on terminated swaps	10,407	7,247	10,645
Gain on disposal of property and equipment, less write-off of totaled tractors	-23,236	-21,574	-16,674
Gain (Loss) on Sale of Properties	3,018	6,876	0
Impairments	2,308	0	9,366
Equity losses of investee	0	537	1,007
Deferred income taxes	-3,980	102,290	45,753
Provision for losses on accounts receivable	2,844	1,370	977
Non-cash loss on debt extinguishment and write-offs of deferred financing costs and original issue discount	11,994	5,540	22,219
Non-cash equity compensation	5,396	4,645	4,890
Income effect of mark-to-market adjustment of interest rate swaps	-155	805	0
Interest on Central stockholders' loan receivable, pre-acquisition	0	-53	-53
Increase (decrease) in cash resulting from changes in:
Accounts receivable	-63,407	-16,613	-17,534
Inventories and supplies	-562	-912	1,484
Prepaid expenses and other current assets	17,802	-12,013	-1,643
Other assets	14,745	6,296	3,879
Accounts payable, accrued and other liabilities	25,555	4,571	6,951
Net cash provided by operating activities	395,781	473,504	447,118
Cash flows from investing activities:
Decrease in restricted cash	5,212	845	20,046
Change in restricted investments	862	-3,539	-22,275
Funding of note receivable	0	0	-7,500
Proceeds from sale of property and equipment	133,020	119,158	142,684
Capital expenditures	-305,966	-318,271	-314,142
Payments received on notes receivable	5,481	3,868	5,948
Expenditures on assets held for sale	-4,053	-18,415	-12,040
Payments received on assets held for sale	25,326	53,486	12,778
Payments received on equipment sale receivables	368	1,450	5,642
Payments to Acquire Businesses, Net of Cash Acquired	0	-150,302	0
Other investing activities	0	0	-270
Net cash used in investing activities	-139,750	-311,720	-169,129
Cash flows from financing activities:
Repayment of long-term debt and capital leases	-1,224,628	-236,388	-311,935
Proceeds from long-term debt	900,000	26,267	11,304
Payment of deferred loan costs	-11,783	-2,183	-9,023
Net borrowings on revolving line of credit	40,000	14,469	-6,506
Borrowings under accounts receivable securitization	119,000	184,000	255,000
Repayment of accounts receivable securitization	-49,000	-124,000	-231,000
Issuance of Central stockholders' loan receivable, pre-acquisition	0	-30,000	0
Distribution to Central stockholders, pre-acquisition	0	-2,499	-13,605
Proceeds from exercise of stock options and issuance of employee stock purchase plan shares	12,604	13,945	401
Income tax benefit (deficiency) from exercise of stock options	3,730	187	-370
Other financing activities	0	0	-743
Net cash used in financing activities	-210,077	-156,202	-306,477
Net increase (decrease) in cash and cash equivalents	45,954	5,582	-28,488
Cash and cash equivalents at beginning of period	59,178	53,596	82,084
Cash and cash equivalents at end of period	105,132	59,178	53,596
Cash paid during the period for:
Interest	89,341	103,238	121,940
Income taxes	82,776	20,625	22,410
Non-cash investing activities:
Equipment sales receivables	288	1,252	705
Equipment purchase accrual	35,831	7,710	14,361
Notes receivable from sale of assets	5,431	8,089	7,784
Non-cash financing activities:
Accrued deferred loan costs	177	0	0
Capital lease additions	101,581	85,094	38,453
Notes payable from purchase of revenue equipment	0	0	3,775
Insurance premium and software notes payable	37	9,189	7,694
Non-cash distribution to Central stockholders in satisfaction of stockholders' loans receivable, pre-acquisition	0	22,315	0
Non-cash exercise of Central stock options in exchange for stockholders' loans receivable, pre-acquisition	0	3,415	0
Cancellation of Central stockholders' loans receivable at closing of acquisition	$0	$33,295	$0

Description_of_Business_and_Ba

Description of Business and Basis of Presentation Description of Business and Basis of Presentation (Notes)	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Description of Business and Basis of Presentation
	Certain acronyms and terms used throughout this Annual Report on Form 10-K are specific to our company, commonly used in our industry, or are otherwise frequently used throughout our document. Definitions for these acronyms and terms are provided in the "Glossary of Terms," available in the front of this document.
	Description of Business
	Swift is a transportation solutions provider, headquartered in Phoenix, Arizona. As of December 31, 2014, the Company's fleet of revenue equipment included 18,836 tractors (comprised of 13,882 company tractors and 4,954 owner-operator tractors), 61,652 trailers and 9,150 intermodal containers. The Company’s four reportable segments are Truckload, Dedicated, Central Refrigerated and Intermodal.
	Basis of Presentation
	General — The accompanying consolidated financial statements include the accounts of Swift Transportation Company and its wholly-owned subsidiaries. All significant intercompany balances and transactions have been eliminated in preparing the consolidated financial statements. When the Company does not have a controlling interest in an entity, but exerts significant influence over the entity, the Company applies the equity method of accounting. In management's opinion, the accompanying financial statements were prepared in accordance with principles generally accepted in the United States and include all adjustments necessary for the fair presentation of the periods presented.
	Central Acquisition — On August 6, 2013, the Company entered into an SPA with the stockholders of Central, pursuant to which the Company acquired all of the outstanding capital stock of Central for aggregate consideration of approximately $225.0 million. The Company paid approximately $189.0 million in cash to the stockholders of Central and assumed approximately $36.0 million of capital lease obligations and other debt. Cash consideration was primarily funded from borrowings on the Company's then-existing credit facilities, including $85.0 million from the Company's revolving line of credit and $100.0 million from the Company's accounts receivable securitization facility. Pursuant to the SPA, within 90 days after the closing date, the Company prepared a final closing statement setting forth the final estimate of the purchase price. As a result of this process and calculation, the purchase price was increased by $2.4 million.
	At closing, a portion of the purchase price was placed in escrow to secure payment of any post-closing adjustments to the purchase price and to secure the seller’s indemnification obligations to the Company. Jerry Moyes, Swift's Chief Executive Officer and controlling stockholder, also contributed into escrow 1,131,862 shares of Swift Class B common stock to further secure such indemnification obligations.
	Mr. Moyes was the majority stockholder of Central prior to the Central Acquisition. Given Mr. Moyes’ interests in the temperature-controlled truckload industry, our board of directors established a special committee comprised solely of independent and disinterested directors in May of 2011 to evaluate Swift’s expansion of its temperature-controlled operations. The special committee evaluated alternative business opportunities, including organic growth and various acquisition targets, and negotiated the transaction contemplated by the SPA, with the assistance of its independent financial advisors. Upon the unanimous recommendation of the special committee, the Central Acquisition was approved by the board of directors (with Mr. Moyes not participating in the vote).
	Given Mr. Moyes' controlling interest in both Swift and Central, the Central Acquisition was accounted for using the guidance for transactions between entities under common control as described in ASC Topic 805, Business Combinations. In accordance with ASC Topic 805-30, the Company has recognized the assets and liabilities of Central at their carrying amounts at the date of transfer. As a result, the financial statements of the Company have been recast to reflect the accounts of Central as if it had been consolidated for all previous periods presented.
	The following financial information as of, and for the year ended, December 31, 2012 has been recast to reflect the accounts of Central as if it was consolidated as of January 1, 2012 (in thousands, except per share data):
		31-Dec-12
		Swift			Central			Intercompany
		Transportation			Refrigerated			Elimination
		Company			Transportation Inc.			Entries			Total
	Total current assets	$	674,537		$	68,211		$	(657	)	$	742,091
	Total assets	2,632,178			160,560			(757		)	2,791,981
	Total current liabilities	323,293			60,813			(657		)	383,449
	Total liabilities	2,402,067			100,367			(657		)	2,501,777
	Total stockholders' equity	230,111			60,193			(100		)	290,204
		2012
		Swift			Central			Intercompany
		Transportation			Refrigerated			Elimination
		Company			Transportation Inc.			Entries			Total
	Operating revenue	$	3,493,182		$	484,657		$	(1,754	)	$	3,976,085
	Operating income	322,046			29,770			—			351,816
	Net income	114,589			25,498			—			140,087
	Basic earnings per share (1)	$	0.82		$	0.18		$	—		$	1
	Diluted earnings per share (1)	0.82			0.18			—			1
	Net cash provided by operating activities	$	406,556		$	40,562		$	—		$	447,118
	Net cash (used in) provided by investing activities	(172,499		)	3,370			—			(169,129		)
	Net cash used in financing activities	(262,545		)	(43,932		)	—			(306,477		)
	____________
	-1	Represents Central's pro-forma basic and diluted earnings per share based on Swift's diluted weighted average share count for the applicable period.

Summary_of_Significant_Account

Summary of Significant Accounting Policies (Notes)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	Summary of Significant Accounting Policies
	Use of Estimates — The preparation of the consolidated financial statements, in accordance with US-GAAP, requires management to make estimates and assumptions about future events that affect the amounts reported in the Company’s consolidated financial statements and accompanying notes. On an ongoing basis, management evaluates and periodically adjusts its estimates and assumptions, based on historical experience, the impact of the current economic environment, and other key factors. Volatile energy markets, as well as changes in consumer spending have increased the inherent uncertainty in such estimates and assumptions. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates. Significant items subject to such estimates and assumptions include:
	•	carrying amount of property and equipment, intangibles and goodwill;
	•	valuation allowances for receivables, inventories and deferred income tax assets;
	•	valuation of financial instruments;
	•	calculation of share-based compensation;
	•	estimates of claims accruals; and
	•	contingent obligations.
	Segments — The Company uses the “management approach” to determine its reportable segments, as well as to determine the basis of reporting the operating segment information. The management approach focuses on financial information that management uses to make operating decisions. The chief operating decision makers use operating revenues, operating expense categories, operating ratios, operating income and key operating statistics to evaluate performance and allocate resources to the Company’s operations.
	Operating income is the measure of segment profit or loss management uses to evaluate segment performance and allocate resources, which is consistent with US-GAAP for segment reporting. It is the Company’s measure of segment performance. Operating income should not be viewed as a substitute for US-GAAP net income (loss). Management believes the presentation of operating income enhances the understanding of the Company's performance by highlighting the results of operations and the underlying profitability drivers of the business segments. Operating income is defined as operating revenues less operating expenses, before tax.
	Based on the unique nature of the Company's operating structure, revenue-generating assets are interchangeable between segments. Therefore, the Company does not prepare separate balance sheets by segment, as assets are not separately identifiable by segment. The Company allocates depreciation and amortization expense on its property and equipment to the segments based on the actual utilization of the asset by the segment during the period.
	Cash and Cash Equivalents — The Company considers all highly liquid debt instruments purchased with original maturities of three months or less to be cash equivalents.
	Restricted Cash — The Company’s wholly-owned captive insurance companies, Red Rock and Mohave, maintain certain operating bank accounts, working trust accounts and investment accounts. The cash and short-term investments within the accounts are restricted by insurance regulations to fund the insurance claim losses to be paid by the captive insurance companies. Therefore, these cash and short-term investments are classified as restricted cash in the consolidated balance sheets.
	Restricted Investments — The Company accounts for its investments in accordance with ASC Topic 320, Investments - Debt and Equity Securities. Management determines the appropriate classification of its investments in debt securities at the time of purchase and re-evaluates the determination on a quarterly basis. As of December 31, 2014, all of the Company’s investments in fixed-maturity securities were classified as held-to-maturity, as the Company has the positive intent and ability to hold these securities to maturity. Held-to-maturity securities are carried at amortized cost. The amortized cost of debt securities is adjusted using the effective interest rate method for amortization of premiums and accretion of discounts. Amortization and accretion is reported in other (income) expenses in the Company’s consolidated income statements.
	Management periodically evaluates restricted investments for impairment. The assessment of whether impairments have occurred is based on management’s case-by-case evaluation of the underlying reasons for the decline in estimated fair value. Management accounts for other-than-temporary impairments of debt securities using the provisions of Topic 320, Investments – Debt and Equity Securities, related to the recognition of other-than-temporary impairments of debt securities. This guidance requires the Company to evaluate whether it intends to sell an impaired debt security or whether it is more likely than not that it will be required to sell an impaired debt security before recovery of the amortized cost basis. If either of these criteria are met, an impairment equal to the difference between the debt security’s amortized cost and its estimated fair value is recognized in earnings. For impaired debt securities that do not meet these criteria, the Company determines if a credit loss exists with respect to the impaired security. If a credit loss exists, the credit loss component of the impairment (i.e., the difference between the security’s amortized cost and the present value of projected future cash flows expected to be collected) is recognized in earnings and the remaining portion of the impairment is recognized as a component of AOCI.
	Inventories and Supplies — Inventories and supplies consist primarily of spare parts, tires, fuel and supplies and are stated at lower of cost or market. Cost is determined using the first-in, first-out method.
	Property and Equipment — Property and equipment are stated at cost. Costs to construct significant assets include capitalized interest incurred during the construction and development period. Expenditures for replacements and improvements are capitalized. Maintenance and repairs are expensed as incurred. Depreciation on property and equipment is calculated on a straight-line basis over the estimated useful lives of 5 to 40 years for facilities and improvements, 3 to 20 years for revenue and service equipment and 3 to 5 years for furniture and office equipment. Net gains on the disposal of property and equipment are presented in the consolidated income statements within operating income.
	Tires on revenue equipment purchased are capitalized as a component of the related equipment cost when the vehicle is placed in service and depreciated over the life of the vehicle. Replacement tires are classified as inventory and expensed when placed in service.
	Management evaluates its property and equipment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable in accordance with ASC Topic 360, Property, Plant and Equipment. When such events or changes in circumstances occur, management performs a recoverability test that compares the carrying amount with the projected undiscounted cash flows from the use and eventual disposition of the asset or asset group. An impairment is recorded for any excess of the carrying amount over the estimated fair value, which is generally determined using discounted future cash flows. Fair value is determined through various valuation techniques including discounted cash flow models, quoted market values and third-party independent appraisals, as considered necessary.
	Intangible Assets other than Goodwill — The Company’s intangible assets other than goodwill primarily consist of acquired customer relationships and trade names. Amortization of acquired customer relationships is calculated on the 150% declining balance method over the estimated useful life of 15 years. The customer relationship contributed to the Company at May 9, 2007 is amortized over 15 years on a straight-line basis. The trade name has an indefinite useful life and is not amortized, but rather is tested for impairment at least annually, unless events occur or circumstances change between annual tests that would more likely than not reduce the fair value.
	Management reviews its intangible assets for impairment whenever events or circumstances indicate that the carrying amount of the asset may not be recoverable, in accordance with ASC Topic 350, Intangibles-Goodwill and Other. When such events or changes in circumstances occur, management performs a recoverability test that compares the carrying amount with the projected undiscounted cash flows from the use and eventual disposition of the asset or asset group. An impairment is recorded for any excess of the carrying amount over the estimated fair value, which is generally determined using discounted future cash flows.
	Goodwill — Management evaluates goodwill on an annual basis as of November 30th, or more frequently if indicators of impairment exist. The Company assesses qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than the carrying amount. If the Company concludes that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, the Company conducts a two-step quantitative goodwill impairment test. The first step of the impairment test involves comparing the fair values of the applicable reporting units with their carrying values. Management estimates the fair values of its reporting units using a combination of the income and market approaches. If the carrying amount of a reporting unit exceeds the reporting unit’s fair value, then management performs the second step of the goodwill impairment test. The second step of the goodwill impairment test involves comparing the implied fair value of the affected reporting unit’s goodwill with the carrying value of that goodwill. Any amount by which the carrying value of the goodwill exceeds its implied fair value is recognized as an impairment loss. Refer to Note 24 for discussion of the results of the Company's annual evaluation as of November 30, 2014.
	Claims Accruals — The Company is self-insured for a portion of its auto liability, workers’ compensation, property damage, cargo damage, and employee medical expense risk. This self-insurance results from buying insurance coverage that applies in excess of a retained portion of risk for each respective line of coverage. The Company accrues for the cost of the uninsured portion of pending claims by evaluating the nature and severity of individual claims and by estimating future claims development based upon historical claims development trends. The actual cost to settle our self-insured claim liabilities may differ from our reserve estimates due to legal costs, claims that have been incurred but not reported and various other uncertainties, including the inherent difficulty in estimating the severity of the claims and the potential judgment or settlement amount to dispose of the claim.
	Fair Value Measurements — See Note 22 for accounting policies and financial information relating to fair value measurements.
	Revenue Recognition — The Company recognizes operating revenues and the related direct costs of such revenue as of the date the freight is delivered, in accordance with ASC Topic 605-20-25-13, Services for Freight-in-Transit at the End of a Reporting Period.
	The Company recognizes operating lease revenue from leasing tractors and related equipment to owner-operators. Operating lease revenue from rental operations is recognized as earned, which is straight-lined per the rent schedules in the lease agreements. Losses from lease defaults are recognized as offsets to revenue in the amount of earned, but not collected revenue.
	Stock-based Compensation — The Company accounts for stock-based compensation expense using the modified prospective method under ASC Topic 718, Compensation - Stock Compensation. ASC Topic 718 requires that all share-based payments to employees and non-employee directors, including grants of employee stock options, be recognized in the financial statements based upon a grant-date fair value of an award. The Company calculates the number of awards expected to vest as awards granted, less expected forfeitures over the life of the award (estimated at grant date). Compensation expense is recorded based on amortization of the grant-date fair value over a graded vesting period. Unless a material deviation from the assumed forfeiture rate is observed during the term in which the awards are expensed, any adjustment necessary to reflect differences in actual experience is recognized in the period the award becomes payable or exercisable. See Note 17 for additional information relating to the Company’s stock compensation plan.
	Income Taxes — Management accounts for income taxes under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to operating loss and tax credit carryforwards, as well as differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. The effect on deferred tax assets and liabilities of changes in tax rates is recognized in income in the period that includes the enactment date.
	A valuation allowance is provided against deferred tax assets if the Company determines it is more likely than not that such assets will not ultimately be realized.
	The Company does not recognize a tax benefit for uncertain tax positions unless it concludes that it is more likely than not that the benefit will be sustained on audit by the taxing authority based solely on the technical merits of the associated tax position. If the recognition threshold is met, the Company recognizes a tax benefit measured at the largest amount of the tax benefit that, in the management's judgment, is greater than 50% likely to be realized. The Company records interest and penalties related to unrecognized tax positions in income tax expense.
	Derivative Instruments — All financial derivative instruments are recorded on our consolidated balance sheets at estimated fair value. Derivatives not designated as hedges are adjusted to fair value through the Company’s consolidated income statements. Depending on the nature of a derivative that is designated as a hedge, effective changes in its fair value either offset the change in fair value of the hedged assets, liabilities or firm commitments through the Company’s consolidated income statements, or are recorded in AOCI until the hedged item is recorded in the Company’s consolidated income statements. Any portion of a change in a derivative's estimated fair value that is considered to be ineffective, or is excluded from the measurement of effectiveness, is recorded immediately in income.

Restricted_Investments

Restricted Investments	12 Months Ended
	Dec. 31, 2014
Schedule of Investments [Abstract]
Investments	Restricted Investments
	These investments will be used to pay insurance claim losses incurred by the Company’s captive insurance companies, Red Rock and Mohave, and are restricted by insurance regulations.
	The following table presents the cost or amortized cost, gross unrealized gains and losses, and estimated fair value of the Company’s restricted investments (in thousands):
		31-Dec-14
				Gross Unrealized
		Cost or Amortized Cost		Gains		Temporary			Estimated Fair Value
						Losses
	United States corporate securities	$	20,892	$	2	$	(10	)	$	20,884
	Foreign corporate securities	1,503		—		—			1,503
	Negotiable certificate of deposits	2,115		—		—			2,115
	Total restricted investments	$	24,510	$	2	$	(10	)	$	24,502
		December 31, 2013
				Gross Unrealized
		Cost or Amortized Cost		Gains		Temporary			Estimated Fair Value
						Losses
	United States corporate securities	$	20,197	$	2	$	(7	)	$	20,192
	Foreign corporate securities	3,502		—		—			3,502
	Negotiable certificate of deposits	2,115		—		(1		)	2,114
	Total restricted investments	$	25,814	$	2	$	(8	)	$	25,808
	As of December 31, 2014, the contractual maturities of the restricted investments were one year or less. There were 24 securities and 15 securities that were in an unrealized loss position for less than twelve months as of December 31, 2014 and 2013, respectively. The Company did not recognize any impairment losses for the years ended December 31, 2014 or 2013.

Accounts_Receivable

Accounts Receivable	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Accounts Receivable	Accounts Receivable, net
	Accounts receivable balances were as follows (in thousands):
		December 31,
		2014			2013
	Trade customers	$	457,823		$	392,233
	Equipment manufacturers	7,725			6,102
	Other	23,375			27,605
	Total accounts receivable	488,923			425,940
	Less: Allowance for doubtful accounts	(9,924		)	(7,504		)
	Accounts receivable, net	$	478,999		$	418,436
	The following schedule presents the rollforward of the allowance for doubtful accounts (in thousands):
		December 31,
		2014			2013			2012
	Beginning balance	$	7,504		$	7,432		$	6,617
	Provision	2,844			1,370			977
	Recoveries	89			35			103
	Write-offs	(513		)	(1,333		)	(265		)
	Ending balance	$	9,924		$	7,504		$	7,432
	See Note 11 for a discussion of the Company’s accounts receivable securitization program and the related accounting treatment.

Assets_Held_For_Sale

Assets Held For Sale	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Assets Held For Sale	Assets Held for Sale
	Assets held for sale balances were (in thousands):
		December 31,
		2014		2013
	Land and facilities	$	288	$	14,627
	Revenue equipment	2,619		4,641
	Assets held for sale	$	2,907	$	19,268
	As of December 31, 2014 and 2013, assets held for sale are carried at the lower of depreciated cost or estimated fair value, less expected selling costs when the required criteria, as defined by ASC Topic 360, Property, Plant and Equipment, are satisfied. Depreciation ceases on the date that the held for sale criteria are met. The Company expects to sell these assets within the next 12 months. The Company did not recognize any impairment losses for the years ended December 31, 2014, 2013 or 2012.
	During the year ended December 31, 2014, the Company sold five operating properties classified as held for sale with a carrying value of $14.5 million. As a result, the Company recognized $3.0 million in (pre-tax) gain on disposal of property and equipment in the consolidated income statements.
	During the year ended December 31, 2013, the Company sold three non-operating properties classified as held for sale with a carrying value of $25.6 million. As a result the Company recognized $6.9 million in (pre-tax) gain on sale of real property in the consolidated income statements. Additionally, management identified facilities in Utah, Oregon, California and Georgia with a carrying value of $14.1 million as assets held for sale as of December 31, 2013.

Equity_Investment_And_Note_Rec

Equity Investment And Note Receivable - Swift Power Services, LLC	12 Months Ended
	Dec. 31, 2014
Equity Method Investments and Joint Ventures [Abstract]
Equity Investment And Note Receivable - Swift Power Services, LLC	Equity Investment and Note Receivable - Swift Power Services, LLC
	In February 2012, the Company contributed approximately $0.5 million to SPS in return for 49.95% ownership interest. SPS was formed in 2012 for the purpose of acquiring the assets and business of three trucking companies engaged in bulk transporting of water, oil, liquids and pipe to various oil companies drilling in the Bakken shale in northwestern North Dakota. The Company accounts for its interest in SPS using the equity method.
	Additionally, in February 2012, the Company loaned $7.5 million to SPS pursuant to a secured promissory note, which is secured by substantially all of the assets of SPS. SPS failed to make its first scheduled principal payment and quarterly interest payment to the Company on December 31, 2012, which resulted in a $6.0 million pre-tax impairment charge in the fourth quarter of 2012. As a result, this note has been placed on nonaccrual status since December 31, 2012. During the years ended December 31, 2014, 2013 and 2012, the Company recorded equity losses of $0.0 million, $0.3 million and $1.0 million, respectively, in other expense in the Company’s consolidated income statements related to its note receivable and investment in SPS, respectively. As a result of the accumulated equity losses and the impairment recorded during the year ended December 31, 2012, the net carrying value of the investment in SPS is zero as of December 31, 2014 and 2013, and the net carrying value of the note receivable is zero as of December 31, 2014 and 2013, respectively.

Accrued_Liabilities

Accrued Liabilities	12 Months Ended
	Dec. 31, 2014
Accrued Liabilities [Abstract]
Accrued Liabilities	Note 9 — Accrued Liabilities
	The following table presents the composition of accrued liabilities (in thousands):
		December 31,
		2014		2013
	Employee compensation	$	50,398	$	56,427
	Owner-operator lease purchase reserve	10,418		10,335
	Income tax accrual	3,541		4,785
	Accrued owner-operator expenses	6,507		6,866
	Deferred revenue	1,504		484
	Fuel and property taxes	3,812		5,241
	Accrued interest expense	4,216		11,328
	Other	19,933		15,279
	Accrued liabilities	$	100,329	$	110,745

Notes_Receivable

Notes Receivable	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Notes Receivable	Note 8 — Notes Receivable
	Notes receivable are included in "Current portion of notes receivable" and "Other assets" in the consolidated balance sheets and were comprised of (in thousands):
		December 31,
		2014			2013
	Notes receivable due from owner-operators, with interest rates at 15%, secured by revenue equipment. Terms range from several months to three years	$	13,642		$	13,264
	Other	1,933			2,361
	Total notes receivable	15,575			15,625
	Less: current portion	(9,202		)	(7,210		)
	Long-term notes receivable	$	6,373		$	8,415

Claims_Accruals

Claims Accruals	12 Months Ended
	Dec. 31, 2014
Claims Accruals [Abstract]
Claims Accruals	Claims Accruals
	Claims accruals represent accruals for the uninsured portion of outstanding claims at year end. The current portion reflects the amount of claims expected to be paid in the following year. The Company’s insurance program for workers’ compensation, group medical liability, auto and collision liability, physical damage and cargo damage involves self-insurance with varying risk retention levels.
	Claims accruals were comprised of the following (in thousands):
		December 31,
		2014			2013
	Auto and collision liability	$	112,548		$	102,462
	Workers’ compensation liability	82,439			70,145
	Owner-operator claims liability	13,233			8,610
	Group medical liability	12,064			9,946
	Cargo damage liability	4,660			2,888
	Claims accrual	224,944			194,051
	Less: current portion	(81,251		)	(75,469		)
	Long-term claim accruals	$	143,693		$	118,582

Accounts_Receivable_Securitiza

Accounts Receivable Securitization	12 Months Ended
	Dec. 31, 2014
Transfers and Servicing [Abstract]
Accounts Receivable Securitization	Accounts Receivable Securitization
	In June 2013, SRCII entered into the 2013 RSA with unrelated financial entities (the "Purchasers") to replace the Company's prior 2011 RSA, and to sell, on a revolving basis, undivided interests in the Company’s accounts receivable. Pursuant to the 2013 RSA, the Company’s receivable originator subsidiaries sell all of their eligible accounts receivable to SRCII, which in turn sells a variable percentage ownership interest in its accounts receivable to the Purchasers. The 2013 RSA is subject to customary fees and contains various customary affirmative and negative covenants, representations and warranties, and default and termination provisions. Collections on the underlying receivables by the Company are held for the benefit of SRCII and the Purchasers in the facility and are unavailable to satisfy claims of the Company and its subsidiaries. As discussed in Note 1, the Company borrowed $100.0 million under the 2013 RSA to fund a portion of the cash consideration paid for the Central Acquisition.
	The following table summarizes the key differences between the current and previous securitization programs (dollar amounts in thousands):
		2013 RSA			2011 RSA
	Effective	Jun-13			Jun-11
	Borrowing capacity (1)	$	375,000		$	275,000
	Final maturity date	July 13, 2016			June 8, 2014
	Unused commitment fee rate	35 basis points			40 basis points
	Program fees on outstanding balances	commercial paper rates + 95 basis points			commercial paper rates + 125 basis points
	____________
	(1) On September 26, 2014, the Company exercised an accordion option, increasing borrowing capacity on the 2013 RSA from $325.0 million to $375.0 million.
	The facility qualifies for treatment as a secured borrowing under ASC Topic 860, Transfers and Servicing. As such, outstanding amounts are classified as liabilities on the Company’s consolidated balance sheets. Ending balances related to the 2013 RSA were as follows (in thousands):
		December 31,
		2014			2013
	Total available borrowing base	$	360,700		$	300,800
	Less: Outstanding balance	(334,000		)	(264,000		)
	Available balance	$	26,700		$	36,800
	As of December 31, 2014 and December 31, 2013, interest accrues on the aggregate principal balance at a rate of 0.8% and 1.1%, respectively. Program fees and unused commitment fees are recorded in interest expense in the Company's consolidated income statements. The Company incurred program fees of $3.5 million, $3.1 million and $3.3 million, during the years ended December 31, 2014, 2013 and 2012, respectively.

Debt_And_Financing_Transaction

Debt And Financing Transactions	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Debt And Financing Transactions	Debt and Financing
	Other than the Company’s accounts receivable securitization as discussed in Note 11 and its outstanding capital lease obligations as discussed in Note 13, the Company's long-term debt consisted of the following (in thousands):
		December 31,
		2014				2013
	2014 Agreement: Term Loan A, due June 2019	$	500,000			$	—
	2014 Agreement: Term Loan B, due June 2021, net of $920 OID as of December 31, 2014	396,080				—
	2013 Agreement: Term Loan B-1 tranche, due December 2016	—				229,000
	2013 Agreement: Term Loan B-2 tranche, due December 2017	—				410,000
	Senior Notes, due November 15, 2018, net of $6,175 OID as of December 31, 2013	—				493,825
	Other	6,980				17,480
	Long-term debt	903,060				1,150,305
	Less: current portion	(31,445		)		(11,387		)
	Noncurrent portion of long term debt	$	871,615			$	1,138,918
	Revolving line of credit (1)	$	57,000			$	17,000
	Long-term debt, including revolving line of credit	$	960,060			$	1,167,305
	____________
	-1	In addition to borrowings, the Company also had outstanding letters of credit of $100.3 million under the $450.0 million Revolver at December 31, 2014 and $108.5 million under the $400.0 million Revolver at December 31, 2013, primarily related to workers' compensation and self-insurance liabilities.
	Credit Agreements
	The Company entered into the 2014 Agreement on June 9, 2014, which included a delayed-draw first lien Term Loan A tranche, a first lien Term Loan B tranche, and a revolving credit line. The 2014 Agreement replaced the then-existing revolving credit line, as well as the first lien term loan B-1 and B-2 tranches of the 2013 Agreement, which had outstanding principal balances at closing of $229.0 million and $371.0 million, respectively. Upon closing, the Company drew $164.0 million on the Revolver and $50.0 million on the Term Loan A. The Company subsequently drew the remaining $450.0 million available on the Term Loan A to facilitate redemption of the Senior Notes in November 2014.
	The Revolver and Term Loan A of the 2014 Agreement contain certain financial covenants with respect to a maximum leverage ratio and a minimum consolidated interest coverage ratio. The 2014 Agreement removed any financial covenants related to the term loan B tranche. Further, the 2014 Agreement removed the maximum capital expenditures covenant and also provides for improved flexibility regarding the use of proceeds from asset sales, payment of dividends, stock buybacks, and equipment financing. In addition to the financial covenants, the 2014 Agreement includes customary events of default, including a change in control default and certain affirmative and negative covenants, including, but not limited to, restrictions, subject to certain exceptions, on incremental indebtedness, asset sales, certain restricted payments (including dividends), certain incremental investments or advances, transactions with affiliates, engaging in additional business activities, and prepayments of certain other indebtedness.
	The credit facility is secured by substantially all of the assets of the Company and is guaranteed by Swift Transportation Company, IEL, Central Refrigerated Transportation, LLC and its subsidiaries, Swift Transportation Co. and its domestic subsidiaries other than its captive insurance subsidiaries, driver academy subsidiary, and its bankruptcy-remote special purpose subsidiary.
	The following tables present the key terms of the current and previous credit agreements (dollars in thousands):
	2014 Agreement		Term Loan A		Term Loan B		Revolver
	Maximum borrowing capacity		$500,000		$400,000		$450,000
	Final maturity date		June 9, 2019		June 9, 2021		June 9, 2019
	Interest rate base		LIBOR		LIBOR		LIBOR
	LIBOR floor		—%		0.75%		—%
	Interest rate minimum margin (1)		1.50%		3.00%		1.50%
	Interest rate maximum margin (1)		2.25%		3.00%		2.25%
	Minimum principal payment - amount (2)		$5,625		$1,000		$—
	Minimum principal payment - frequency		Quarterly		Quarterly		Once
	Minimum principal payment - commencement date (2)		31-Mar-15		30-Jun-14		30-Jun-19
	____________
	-1	Interest rate margins on the Term Loan A and Revolver are based on the Company's consolidated leverage ratio. Additionally, after December 31, 2014, interest rate margins on the Term Loan B will be determined by the Company's consolidated leverage ratio, and will range from 2.75% to 3.00%. As of December 31, 2014, interest accrues at 2.16% and 3.75% on the Term Loan A and Term Loan B, respectively.
	The commitment fee for the unused portion of the Revolver is also based on the Company's consolidated leverage ratio, and ranges from 0.25% to 0.35%. As of December 31, 2014, commitment fees on the unused portion of the Revolver accrue at 0.30% and letter of credit fees accrue at 2.00%.
	-2	Commencing in March 2017, the minimum principal payment amount on the Term Loan A is $11.3 million.
	2013 Agreement		Term Loan B-1		Term Loan B-2		Revolver
	Maximum borrowing capacity		$350,000		$410,000		$400,000
	Final maturity date		21-Dec-16		21-Dec-17		21-Sep-16
	Interest rate base		LIBOR		LIBOR		LIBOR
	LIBOR floor		—%		1.00%		—%
	Interest rate minimum margin (1)		2.75%		3.00%		3.00%
	Interest rate maximum margin (1)		2.75%		3.00%		3.25%
	____________
	-1	As of December 31, 2013, interest accrued at 2.92% and 4.00% on the Company’s first lien term loan B-1 and B-2 tranches, respectively. The commitment fee for the unused portion of the $400.0 million revolving credit facility ranged from 0.25% to 0.50%, depending on the Company’s consolidated leverage ratio.
	Senior Notes
	In November 2014, the Company redeemed, in full, the remaining $428.1 million face value of its Senior Notes. This was primarily funded with the proceeds from the Company’s Term Loan A. The Company paid 105.0% of face value, plus accrued and unpaid interest, to call the Senior Notes. While the redeemed Senior Notes incurred interest at 10.0%, the source of funds from the Term Loan A incurs interest at LIBOR plus applicable margin of 1.50% to 2.25%. The November 2014 redemption followed a series of open market purchases that occurred in the first nine months of 2014, in which the Company used cash on hand to repurchase $71.9 million in principal of the Senior Notes. Including the November 2014 redemption, the Company repurchased the entire $500.0 million in principal of the Senior Notes during 2014, at an average price of 105.58% of face value. These transactions significantly reduced Swift’s average cost of debt, as compared to the beginning of the year.
	Payment of principal and interest on the Senior Notes was previously guaranteed by certain of the Company’s 100% owned domestic subsidiaries. Pursuant to the terms of the indenture governing the Senior Notes, the guarantees were subject to release at which time the subsidiaries no longer had indebtedness that would have required a guarantee. Thus, the Company's redemption of the Senior Notes on November 15, 2014, released the related guarantee.
	Central Debt
	As discussed in Note 1, the Company completed the Central Acquisition on August 6, 2013. As of December 31, 2014, and December 31, 2013, Central had outstanding principal balances of $1.2 million and $2.2 million, respectively, for various notes payable to finance companies secured by revenue equipment with due dates through May 2015. Additionally, at the closing of the Central Acquisition, the Company repaid a Central note payable to a bank secured by real estate with a due date of March 2016 including outstanding principal and accrued interest of $3.4 million.
	Central Credit Facilities
	On March 8, 2013, Central entered into a credit agreement ("Central 2013 Agreement") to replace its then existing Central 2011 Agreement. The Central 2013 Agreement included a $50.0 million revolving line of credit, subject to certain limits. The agreement also provided a $16.0 million term loan, which included quarterly principal payments with a balloon payment of 30.0%. The term loan accrued interest at the same rates as the revolving line of credit. As discussed in Note 1, in conjunction with the Central Acquisition on August 6, 2013, the Company repaid the outstanding principal, unpaid interest and bank fees associated with Central's revolving line of credit and term loan under the Central 2013 Agreement for aggregate payments of $38.0 million.
	Deferred Loan Costs and Loss on Debt Extinguishment
	Deferred loan costs of $10.4 million at December 31, 2014 and $8.9 million at December 31, 2013 were recorded in "Other assets" in the consolidated balance sheets.
	For the year ended December 31, 2014, the $39.9 million loss on debt extinguishment related to the Company's redemption of its Senior Notes and the replacement of the 2013 Agreement with the 2014 Agreement. For the year ended December 31, 2013, the $5.5 million loss on debt extinguishment related to the Company's replacement of the 2012 Agreement with the 2013 Agreement. For the year ended December 31, 2012, the $22.2 million loss on debt extinguishment primarily related to the Company's replacement of its then-existing first lien term loan with the 2012 Agreement, as well as the call of its remaining 12.50% fixed rate notes, due 2017.

Purchase_Commitments

Purchase Commitments	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments	Purchase Commitments
	As of December 31, 2014, the Company had commitments outstanding to acquire revenue equipment in 2015 for approximately $791.3 million and in 2016-2017 for approximately $379.6 million. The Company generally has the option to cancel tractor purchase orders with 60 days to 90 days notice prior to the scheduled production, although the notice period has lapsed for approximately 13.0% of the tractor commitments outstanding as of December 31, 2014. These purchases are expected to be financed by the combination of operating leases, capital leases, debt, proceeds from sales of existing equipment and cash flows from operations.
	As of December 31, 2014, the Company had outstanding purchase commitments of approximately $3.2 million for facilities and non-revenue equipment. Factors such as costs and opportunities for future terminal expansions may change the amount of such expenditures.

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies
	The Company is involved in certain claims and pending litigation primarily arising in the normal course of business. The majority of these claims relate to workers compensation, auto collision and liability, and physical damage and cargo damage. The Company expenses legal fees as incurred and accrues for the uninsured portion of contingent losses from these and other pending claims when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Based on the knowledge of the facts and, in certain cases, advice of outside counsel, management believes the resolution of claims and pending litigation, taking into account existing reserves, will not have a material adverse effect on the Company. Moreover, the results of complex legal proceedings are difficult to predict and the Company’s view of these matters may change in the future as the litigation and events related thereto unfold.
	For certain cases described below, management is unable to provide a meaningful estimate of the possible loss or range of loss because, among other reasons, (i) the proceedings are in various stages; (ii) damages have not been sought; (iii) damages are unsupported and/or exaggerated; (iv) there is uncertainty as to the outcome of pending appeals and/or (v) there are significant factual issues to be resolved.  For these cases, however, management does not believe, based on currently available information, that the outcomes of these proceedings will have a material adverse effect on our financial condition, though the outcomes could be material to our operating results for any particular period, depending, in part, upon the operating results for such period.
	Arizona Owner-operator Class Action Litigation
	On January 30, 2004, a class action lawsuit was filed by Leonel Garza on behalf of himself and all similarly situated persons against Swift Transportation: Garza v. Swift Transportation Co., Inc., Case No. CV7-472 ("the Garza Complaint"). The putative class originally involved certain owner-operators who contracted with the Company under a 2001 Contractor Agreement that was in place for one year. The putative class is alleging that the Company should have reimbursed owner-operators for actual miles driven rather than the contracted and industry standard remuneration based upon dispatched miles. The trial court denied plaintiff’s petition for class certification, the plaintiff appealed and on August 6, 2008, the Arizona Court of Appeals issued an unpublished Memorandum Decision reversing the trial court’s denial of class certification and remanding the case back to the trial court. On November 14, 2008, the Company filed a petition for review to the Arizona Supreme Court regarding the issue of class certification as a consequence of the denial of the Motion for Reconsideration by the Court of Appeals. On March 17, 2009, the Arizona Supreme Court granted the Company’s petition for review, and on July 31, 2009, the Arizona Supreme Court vacated the decision of the Court of Appeals opining that the Court of Appeals lacked automatic appellate jurisdiction to reverse the trial court’s original denial of class certification and remanded the matter back to the trial court for further evaluation and determination. Thereafter, the plaintiff renewed the motion for class certification and expanded it to include all persons who were employed by Swift as employee drivers or who contracted with Swift as owner-operators on or after January 30, 1998, in each case who were compensated by reference to miles driven. On November 4, 2010, the Maricopa County trial court entered an order certifying a class of owner-operators and expanding the class to include employees. Upon certification, the Company filed a motion to compel arbitration, as well as filing numerous motions in the trial court urging dismissal on several other grounds including, but not limited to the lack of an employee as a class representative, and because the named owner-operator class representative only contracted with the Company for a three-month period under a one-year contract that no longer exists. In addition to these trial court motions, the Company also filed a petition for special action with the Arizona Court of Appeals arguing that the trial court erred in certifying the class because the trial court relied upon the Court of Appeals ruling that was previously overturned by the Arizona Supreme Court. On April 7, 2011, the Arizona Court of Appeals declined jurisdiction to hear this petition for special action and the Company filed a petition for review to the Arizona Supreme Court. On August 31, 2011, the Arizona Supreme Court declined to review the decision of the Arizona Court of Appeals. In April 2012, the trial court issued the following rulings with respect to certain motions filed by Swift: (1) denied Swift’s motion to compel arbitration; (2) denied Swift’s request to decertify the class; (3) granted Swift’s motion that there is no breach of contract; and (4) granted Swift’s motion to limit class size based on statute of limitations. On November 13, 2014, the court denied plaintiff's motion to add new class representatives for the employee class and therefore the employee class remains without a plaintiff class representative. Swift has two motions for summary judgment pending before the court: 1) to dismiss any claims related to the employee class since there is no class representative; and 2) to dismiss plaintiff's claim of breach of a duty of good faith and fair dealing. The Company intends to continue to pursue all available appellate relief supported by the record, which the Company believes demonstrates that the class is improperly certified and, further, that the claims raised have no merit. The Company retains all of its defenses against liability and damages. The final disposition of this case and the impact of such final disposition cannot be determined at this time.
	Ninth Circuit Owner-operator Misclassification Class Action Litigation
	On December 22, 2009, a class action lawsuit was filed against Swift Transportation and IEL: Virginia VanDusen, John Doe 1 and Joseph Sheer individually and on behalf of all other similarly situated persons v. Swift Transportation Co., Inc., Interstate Equipment Leasing, Inc., Jerry Moyes, and Chad Killebrew, Case No. 9-CIV-10376 filed in the United States District Court for the Southern District of New York ("the Sheer Complaint"). The putative class involves owner-operators alleging that Swift Transportation misclassified owner-operators as independent contractors in violation of the federal Fair Labor Standards Act ("FLSA"), and various New York and California state laws and that such owner-operators should be considered employees. The lawsuit also raises certain related issues with respect to the lease agreements that certain owner-operators have entered into with IEL. At present, in addition to the named plaintiffs, approximately 200 other current or former owner-operators have joined this lawsuit. Upon Swift’s motion, the matter has been transferred from the United States District Court for the Southern District of New York to the United States District Court in Arizona. On May 10, 2010, the plaintiffs filed a motion to conditionally certify an FLSA collective action and authorize notice to the potential class members. On September 23, 2010, plaintiffs filed a motion for a preliminary injunction seeking to enjoin Swift and IEL from collecting payments from plaintiffs who are in default under their lease agreements and related relief. On September 30, 2010, the District Court granted Swift’s motion to compel arbitration and ordered that the class action be stayed pending the outcome of arbitration. The District Court further denied plaintiff’s motion for preliminary injunction and motion for conditional class certification. The District Court also denied plaintiff’s request to arbitrate the matter as a class.
	The plaintiff filed a petition for a writ of mandamus to the Ninth Circuit Court of Appeals asking that the District Court’s September 30, 2010 order be vacated. On July 27, 2011, the Ninth Circuit Court of Appeals denied the plaintiff’s petition for writ of mandamus and thereafter the District Court denied plaintiff’s motion for reconsideration and certified its September 30, 2010 order. The plaintiffs filed an interlocutory appeal to the Ninth Circuit Court of Appeals to overturn the District Court’s September 30, 2010 order to compel arbitration alleging that the agreement to arbitrate is exempt from arbitration under Section 1 of the Federal Arbitration Act (“FAA”) because the class of plaintiffs allegedly consists of employees exempt from arbitration agreements. On November 6, 2013, the Ninth Circuit Court of Appeals reversed and remanded, stating its prior published decision “expressly held that a district court must determine whether an agreement for arbitration is exempt from arbitration under Section 1 of the FAA as a threshold matter". As a consequence of this determination by the ninth Circuit Court of Appeals being different from a decision of the Eighth Circuit Court of Appeals on a similar issue, on February 4, 2014, the Company filed a petition for writ of certiorari to the U.S. Supreme Court to address whether the district court or arbitrator should determine whether the contract is an employment contract exempt from Section 1 of the Federal Arbitration Act. On June 16, 2014, the U.S. Supreme Court denied the Company’s petition for writ of certiorari. The Company intends to vigorously defend against any proceedings. The final disposition of this case and the impact of such final disposition cannot be determined at this time.
	California Wage, Meal and Rest Employee Class Actions
	On March 22, 2010, a class action lawsuit was filed by John Burnell, individually and on behalf of all other similarly situated persons against Swift Transportation: John Burnell and all others similarly situated v. Swift Transportation Co., Inc., Case No. CIVDS 1004377 filed in the Superior Court of the State of California, for the County of San Bernardino ("the Burnell Complaint"). On September 3, 2010, upon motion by Swift, the matter was removed to the United States District Court for the Central District of California, Case No. EDCV10-809-VAP. The putative class includes drivers who worked for Swift during the four years preceding the date of filing alleging that Swift failed to pay the California minimum wage, failed to provide proper meal and rest periods and failed to timely pay wages upon separation from employment. The Burnell Complaint was subject to a stay of proceedings pending determination of similar issues in a case unrelated to Swift, Brinker v. Hohnbaum, which was then pending before the California Supreme Court. A ruling was entered in the Brinker matter and in August 2012 the stay in the Burnell Complaint was lifted. On April 9, 2013 the Company filed a motion for judgment on the pleadings requesting dismissal of plaintiff's claims related to alleged meal and rest break violations under the California Labor Code alleging that such claims are preempted by the Federal Aviation Administration Authorization Act. On May 29, 2013, the U.S. District Court for the Central District of California granted the Company's motion for judgment on the pleadings and dismissed plaintiff's claims that are based on alleged violations of meal and rest periods set forth in the California Labor Code. Plantiff has appealed. Minimum wage claims (specifically that pay per-mile fails to compensate drivers for non-driving related services) timeliness of such pay and issue of class certification remain pending.
	On April 5, 2012, the Company was served with an additional class action complaint alleging facts similar to those as set forth in the Burnell Complaint. This new class action is James R. Rudsell, on behalf of himself and all others similarly situated v. Swift Transportation Co. of Arizona, LLC and Swift Transportation Company, Case No. CIVDS 1200255, in the Superior Court of California for the County of San Bernardino ("the Rudsell Complaint"). The Rudsell Complaint has been stayed pending a resolution in the Burnell Complaint.
	The issue of class certification must first be resolved before the court will address the merits of the case, and we retain all of our defenses against liability and damages pending a determination of class certification. The Company intends to vigorously defend certification of the class in both matters, as well as the merits of these matters, should the classes be certified. The final disposition of both cases and the impact of such final dispositions of these cases cannot be determined at this time.
	California Wage and Hour Class Action
	On September 25, 2014, a class action lawsuit was filed by Lawrence Peck on behalf of himself and all other similarly situated persons against Swift Transportation: Peck v. Swift Transportation Co. Arizona, LLC in the Superior Court of California, County of Riverside ("the Peck Complaint"). The putative class includes current and former non-exempt employee truck drivers who performed services in California within the four-year statutory period alleging that Swift failed to pay for all hours worked (specifically that pay-per-mile fails to compensate drivers for non-driving related services), failed to pay overtime, failed to properly reimburse work-related expenses, failed to timely pay wages and failed to provide accurate wage statements.
	The issue of class certification must first be resolved before the court will address the merits of the case, and the Company retains all of its defenses against liability and damages pending a determination of class certification. The Company intends to vigorously defend certification of the class, as well as the merits, should the class be certified. The final disposition of the case and the impact of such final disposition cannot be determined at this time.
	Washington Overtime Class Action
	On September 9, 2011, a class action lawsuit was filed by Troy Slack on behalf of himself and all similarly situated persons against Swift Transportation: Troy Slack, et al v. Swift Transportation Co. of Arizona, LLC and Swift Transportation Corporation in the State Court of Washington, Pierce County ("the Slack Complaint"). The Slack Complaint was removed to federal court on October 12, 2011, case number 11-2-114380. The putative class includes all current and former Washington State based employee drivers during the three-year statutory period alleging that they were not paid overtime in accordance with Washington State law and that they were not properly paid for meals and rest periods. On November 23, 2013, the court entered an order on plaintiffs' motion to certify the class. The court only certified the class as it pertains to dedicated route drivers and did not certify any other class or claims, including any class related to over the road drivers (“OTR Drivers”). The court also further limited the class of dedicated drivers to only those dedicated drivers that either begin or end their shift in the state of Washington and therefore are Washington-based employees. Swift is appealing the limited certification of the Washington dedicated drivers.
	The issue of class certification must first be resolved before the court will address the merits of the case, and the Company retains all of its defenses against liability and damages pending a determination of class certification. The Company intends to vigorously defend certification of the class, as well as the merits of these matters, should the class be certified. The final disposition of this case and the impact of such final disposition of this case cannot be determined at this time.
	Utah Minimum Wage Collective Action
	On October 8, 2013, a collective action lawsuit was filed by Jacob Roberts on behalf of himself and all similarly situated persons against Central Refrigerated Service, Inc., Jon Isaacson, Bob Baer and John Does 1-10: Jacob Roberts and Collective Action Plaintiffs John Does 1-10 v. Central Refrigerated Service, Inc., Jon Isaacson, Bob Baer and John Does 1-10 in the United States District Court for the District of Utah, Case No. 2;13-ev-00911-EJF ("the Roberts Complaint"). The putative nationwide class includes employees alleging that candidates for employment within the three-year statutory period in Utah were not paid proper compensation pursuant to the FLSA, specifically that the putative collective action plaintiffs were not paid the state-mandated minimum wage for orientation, travel, and training.
	The issue of collective action certification in the Roberts Complaint must first be resolved before the court will address the merits of the case, and the Company retains all of its defenses against liability and damages, pending a determination of collective action certification. Central intends to vigorously defend against collective action certification, as well as the merits of this matter, should the collective action be certified. The final disposition of this case and the impact of such final disposition of this case cannot be determined at this time.
	Utah Collective and Individual Arbitration
	On June 1, 2012, a collective and class action complaint was filed by Gabriel Cilluffo, Kevin Shire and Bryan Ratterree individually and on behalf of themselves and all similarly situated persons against Central Refrigerated Services, Inc., Central Leasing, Inc., Jon Isaacson, and Jerry Moyes: Gabriel Cilluffo, Kevin Shire and Bryan Ratterree individually and on behalf themselves and all similarly situated persons v. Central Refrigerated Services, Inc., Central Leasing, Inc., Jon Isaacson, and Jerry Moyes in the United States District Court for the Central District of California, Case No. ED CV 12-00886 ("the Cilluffo Complaint"). The putative class involves owner-operators alleging that Central misclassified owner-operators as independent contractors in violation of the FLSA, and that such owner-operators should be considered employees. The lawsuit also raises a claim of forced labor and state law contractual claims. On September 24, 2012, the California District Court ordered that the FLSA claim proceed to collective arbitration under the Utah Uniform Arbitration Act (“UUAA”) and not the FAA. The September 24, 2012 order directed the arbitrator to determine the validity of proceeding as a collective arbitration under the UUAA, and then if the arbitrator determines that such collective action is permitted, then the arbitrator is to consider the plaintiff’s FLSA claim. On November 8, 2012, the California District Court entered a clarification order clarifying that the plaintiff’s FLSA claim was to proceed to collective arbitration under the UUAA, but the plaintiff’s forced labor claim and state law contractual claims were to proceed as individual arbitrations for those plaintiffs seeking to pursue those specific claims. Central filed a motion for reconsideration and a motion for interlocutory appeal of the California District Court’s orders, both of which were denied and the claims are proceeding to collective and individual arbitration as originally ordered. On December 9, 2013 the arbitrator determined that the issue of misclassification as it relates to the FLSA will proceed as a collective arbitration, however the plaintiffs forced labor claim and state law claims of contractual misrepresentation and breach of contract must proceed on an individual arbitration basis and not as a class.
	Central intends to vigorously defend collective arbitration in the Cilluffo Complaint, as well as the merits of the FLSA claim and any individual arbitration matters that are filed, and proceed on the forced labor and state contract law claims. The final disposition of this case and the impact of such final disposition of this case cannot be determined at this time.
	Environmental Notice
	On April 17, 2009, the Company received a notice from the Lower Willamette Group ("LWG"), advising that there are a total of 250 potentially responsible parties ("PRPs"), with respect to alleged environmental contamination of the Lower Willamette River in Portland, Oregon designated as the Portland Harbor Superfund site ("the Site"), and that as a previous landowner at the Site, the Company has been asked to join a group of 60 PRPs and proportionately contribute to (i) reimbursement of funds expended by LWG to investigate environmental contamination at the Site and (ii) remediation costs of the same, rather than be exposed to potential litigation. Although the Company does not believe it contributed any contaminants to the Site, the Company was at one time the owner of property at the Site and the Comprehensive Environmental Response, Compensation and Liability Act imposes a standard of strict liability on property owners with respect to environmental claims. Notwithstanding this standard of strict liability, the Company believes our potential proportionate exposure to be minimal and not material. No formal complaint has been filed in this matter. The Company’s pollution liability insurer has been notified of this potential claim. The Company does not believe the outcome of this matter is likely to have a material adverse effect on Swift. However, the final disposition of this matter and the impact of such final disposition cannot be determined at this time.
	Other Environmental
	The Company's tractors and trailers are involved in motor vehicle accidents, experience damage, mechanical failures and cargo issues as an incidental part of its normal ordinary course of operations.  From time to time, these matters result in the discharge of diesel fuel, motor oil or other hazardous materials into the environment.  Depending on local regulations and who is determined to be at fault, the Company is sometimes responsible for the clean-up costs associated with these discharges.  As of December 31, 2014, the Company's estimate for its total legal liability for all such clean-up and remediation costs was approximately $1.0 million in the aggregate for all current and prior year claims.

Derivative_Financial_Instrumen

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments
	The Company has typically used pay-fixed/receive-variable interest rate swaps to reduce the Company’s aggregate exposure to interest rate risk. the Company does not enter into derivative agreements for speculative purposes.
	Swift Interest Rate Swaps
	In April 2011, as contemplated by the then existing credit facility, the Company entered into two forward-starting interest rate swap agreements with a notional amount of $350.0 million. These interest rate swaps were effective in January 2013 and have a maturity date of July 2015. On April 27, 2011 (“designation date”), the Company designated and qualified these interest rate swaps as cash flow hedges. Subsequent to the designation date, the effective portion of the changes in estimated fair value of the designated swaps was recorded in AOCI, and thereafter reclassified to derivative interest expense in the periods that the interest on the hedged debt affected earnings. The Company began accruing for hedged interest in January 2013. Refer to Note 22 for amounts and the Company's methodology related to fair value of interest rate swaps.
	On March 7, 2013, the Company entered into the 2013 Agreement, as discussed in Note 12. Due to the incorporation of a new interest rate floor provision in the 2013 Agreement, the Company concluded, as of February 28, 2013, that the outstanding interest rate swaps were no longer highly effective in achieving offsetting changes in cash flows related to the hedged interest payments. As a result, the Company de-designated the hedges as of February 28, 2013 (“de-designation date”), at which time the effective portion of the change in fair value of interest rate swaps (previously recorded in AOCI) was, and will continue to be, amortized as derivative interest expense over the period of the originally designated hedged interest payments through July 2015. Following the de-designation date, changes in fair value of the interest rate swaps are immediately recognized as derivative interest expense in the consolidated income statements.
	Central Interest Rate Swap
	In connection with the note payable to a bank due March 2016, Central entered into an interest rate swap agreement to manage its interest rate exposure. The interest rate swap agreement was designated as a cash flow hedge. The interest rate swap agreement reduced the effect of changes in interest rates on the floating rate associated with this note. The agreement effectively changed Central's interest rate exposure on this note to a fixed rate of 8.9%. In conjunction with the Central Acquisition on August 6, 2013, the Company paid $0.3 million to terminate Central's interest rate swap agreements.
	Effects on Income and AOCI
	Activities related to AOCI net of tax, are presented in the consolidated statement of stockholders' equity, and primarily pertain to derivative financial instruments. The tax effects are presented in the statements of comprehensive income. Activities related to foreign currency transactions were immaterial.
	The following table presents pre-tax gains (losses) from changes in fair value, included in AOCI and earnings (in thousands):
		2014				2013				2012
	Losses recognized in AOCI from cash flow hedges (effective portion)	$	—			$	145			$	2,786
	Loss reclassified from AOCI into income from cash flow hedges (effective portion)	$	6,218			$	3,143			$	5,101
	Loss recognized in income from de-designated derivative contracts	277				709				—
	Derivative interest expense	$	6,495			$	3,852			$	5,101
	As of December 31, 2014, $4.0 million of deferred losses on derivatives in AOCI are expected to be reclassified to earnings within the next 12 months.
	Losses on cash flow hedging, reclassified out of AOCI were as follows (in thousands):
			Year Ended December 31,
		Reclassified to:	2014				2013				2012
	Interest rate swaps	Derivative interest expense	$	6,218			$	3,143			$	5,101
	Income tax (benefit) expense	Income tax expense	(2,220		)		(1,226		)		1,989
		Net income	$	3,998			$	1,917			$	7,090

Equity_and_Stockbased_Compensa

Equity and Stock-based Compensation	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Stockholders' Equity	Equity and Stock-based Compensation
	Common Stock
	Holders of Class A common stock are entitled to one vote per share, while holders of Class B common stock are entitled to two votes per share on any matter to be voted on by our stockholders. Holders of Class A and Class B common stock vote together as a single class on all matters submitted to a vote of stockholders, unless otherwise required by law, except that a separate vote of each class will be required for:
	•	any merger or consolidation in which holders of shares of Class A common stock receive consideration that is not identical to holders of shares of Class B common stock;
	•	any amendment of Swift Transportation Company’s amended and restated certificate of incorporation or amended and restated bylaws that alters the relative rights of its common stockholders; and
	•	any increase in the authorized number of shares of Class B common stock or the issuance of shares of Class B common stock, other than such increase or issuance required to effect a stock split, stock dividend, or recapitalization pro rata with any increase or issuance of Class A common stock.
	Related Party Common Stock Transactions
	Concurrently with the Company’s IPO in December 2010, Jerry Moyes and certain Moyes Affiliates completed a private placement by an unaffiliated special purpose trust (the “2010 Trust”) of $262.3 million of the 2010 METS, which was required to be settled with up to 23.8 million shares of the Company’s Class A common stock, or cash, on December 31, 2013.
	On December 31, 2013, Mr. Moyes and the Moyes Affiliates chose to deliver 19.5 million shares of Class A common stock to settle the 2010 METS facility which were obtained by entering into a VPF contract on October 29, 2013 with Citibank, N.A.
	To fulfill the VPF contract, Citibank N.A. borrowed 19.5 million shares of Class A common stock from the public market. These shares were sold to Mr. Moyes and certain Moyes Affiliates, through their ownership of M Capital II, and were held as collateral by Citibank N.A. for a new loan that facilitated the purchase of the shares. On December 31, 2013, Citibank delivered the 19.5 million Class A shares to the 2010 Trust in exchange for the 23.8 million shares of Class B common stock held by the 2010 Trust as collateral. The holders of the 2010 METS received their respective portion of 19.5 million shares of Class A common stock as settlement of the facility. Citibank N.A. now holds the 23.8 million shares of Class B common stock transferred from the 2010 Trust and an additional 2.2 million shares of Class B common stock contributed directly by Mr. Moyes and the Moyes Affiliates as collateral for the VPF contract.
	Under the VPF contract, M Capital II is obligated to deliver to Citibank N.A. a variable amount of stock or cash during two twenty trading day periods beginning on January 4, 2016, and July 5, 2016, respectively. Although M Capital II may settle its obligations to Citibank N.A. in cash, any or all of the collateralized shares could be converted into Class A common stock and delivered on such dates to settle such obligations. If settled in cash, management believes Citibank N.A. would likely purchase Class A shares on the open market to settle its short position. If settled in shares, management believes Citibank N.A. would likely use the shares to settle its position. The 2013 VPF contract allows Mr. Moyes and the Moyes Affiliates to retain the same number of shares and voting percentage as they had prior to the inception of the 2013 VPF contract and the settlement of the 2010 METS facility. In addition, Mr. Moyes and the Moyes Affiliates are able to participate in future price appreciation of the Company’s common stock.
	During 2014, 2013 and 2012, the Moyes Affiliates converted shares of common stock on a one-for-one basis as follows:
	Transaction Date		Converted from Class B			Converted to Class A
	30-May-14		(1,450,000	)		1,450,000
	31-Dec-13		(53,298	)		53,298
	12-Mar-12		(1,068,224	)		1,068,224
	Stock Plans
	On March 28, 2014, the board of directors adopted the 2014 Plan, which replaced the 2007 Plan. The 2014 Plan became effective upon stockholder approval on May 8, 2014, after which date no new awards would be granted under the 2007 Plan. The 2007 Plan continues to govern all awards granted under the 2007 Plan until such awards have been exercised, forfeited, canceled or have otherwise expired or terminated.
	The 2014 Plan generally contains the same features, terms and conditions as the 2007 Plan. Additionally, the 2014 Plan did not increase the number of shares of stock available for grant.
	The 2014 Plan permits the payment of cash incentive compensation and authorizes the granting of stock options, stock appreciation rights, restricted stock and RSUs, performance shares and performance share units, cash-based awards, and stock-based awards to the Company's employees and non-employee directors for up to 12.0 million shares of Class A common stock. As of December 31, 2014, the aggregate number of shares remaining available under the 2014 Plan was 7.1 million.
	Stock-based Compensation Expense
	Stock-based compensation expense, which is included in "Salaries, wages and employee benefits" in the consolidated income statements is comprised of the following (in thousands):
		Year Ended December 31,
		2014				2013				2012
	Stock options	$	3,007			$	3,359			$	4,886
	Restricted stock shares and RSUs	1,600				887				4
	Performance shares	789				399				—
	Total stock-based compensation expense	$	5,396			$	4,645			$	4,890
	Income tax benefit	$	1,926			$	1,788			$	1,883
	During 2010, the Company repriced approximately 4.3 million outstanding options that had exercise prices above the IPO price. These options were repriced down to the IPO price of $11.00 per share and were held by approximately 1,100 employees. This resulted in $5.6 million of incremental equity compensation expense recognized over the remaining service period of the repriced options through August 2013.
	The following table presents the total unrecognized stock-based compensation expense and the expected weighted average period over which these expenses will be recognized:
		December 31, 2014
		Expense				Weighted Average Period
		(In thousands)				(In years)
	Stock options	$	1,506			1.27
	Restricted stock shares and RSUs	$	5,234			1.38
	Performance shares	$	1,565			1.15
	Stock Options
	Stock options are the contingent right of award holders to purchase shares of Swift Transportation Company Class A common stock at a stated price for a limited time. For options granted prior to the Company's IPO in December 2010, the exercise price of options granted equaled or exceeded the estimated fair value of the common stock on the date of grant. The estimated fair value of the common stock prior to the Company’s IPO in each case was determined by management based upon a number of factors, including the Company's discounted projected cash flows, comparative multiples of similar companies, the lack of liquidity of the Company's common stock and certain risks the Company faced at the time of the valuation. Options granted prior to the Company's IPO that had an exercise price that exceeded the IPO price of $11.00 were repriced to the IPO price at the time of the IPO. For options granted after the Company’s IPO, the exercise price of options granted equaled the fair value of the Company’s common stock determined by the closing price of the Company’s Class A common stock quoted on the NYSE on the date of grant.
	All options have a ten-year contractual term. The options issued prior to the Company's IPO were granted to two categories of employees. The options granted to the first category of employees vest upon the occurrence of the earliest of: (i) a sale or a change in control of the Company or, (ii) a five-year vesting period at a rate of 33 1/3% following the third anniversary date of the grant. The options granted to the second category of employees vest upon the later of (i) the occurrence of an initial public offering of the Company or (ii) a five-year vesting period at a rate of 33 1/3% following the third anniversary date of the grant. To the extent vested, both types of options become exercisable simultaneous with the closing of the earlier of (i) an initial public offering, (ii) a sale, or (iii) a change in control of the Company. The options granted in 2014 and 2013 have a vesting period of three years at a rate of 33 1/3% per year.
	A summary of the activity related to stock options for the year ended December 31, 2014 was as follows:
		Shares Under			Weighted Average				Weighted Average Remaining Contractual Term		Aggregate
		Option			Exercise Price						Intrinsic
											Value (1)
									(In years)		(In thousands)
	Outstanding at January 1, 2014	4,785,133			$	10.7			5.28		$	55,059
	Granted	175,142			23.3
	Exercised	(1,100,998	)		10.43
	Expired	(7,624	)		10.14
	Forfeited	(86,779	)		12.47
	Outstanding at December 31, 2014	3,764,874			$	11.34			4.68		$	65,089
	Aggregate number of stock options expected to vest at a future date as of December 31, 2014	1,485,666			$	10.87			6.27		$	16,846
	Exercisable at December 31, 2014	2,776,536			$	10.63			6.13		$	49,973
	____________
	-1	The aggregate intrinsic value was computed using the closing share price on December 31, 2014 of $28.63 and on December 31, 2013 of $22.21, as applicable.
	The fair value of each stock option grant is estimated on the grant date using the Black-Scholes-Merton option-pricing model, which uses a number of assumptions to determine the fair value of the options on the grant date. The following table presents the weighted average assumptions used to determine the fair value of stock options issued:
		2014		2013		2012
	Dividend yield	—%		—%		—%
	Risk-free rate of return	1.28%		1.04%		1.20%
	Expected volatility	40.00%		40.80%		41.40%
	Expected term (in years)	5.8		5.8		6.3
	Weighted average fair value of stock options granted	$6.79		$5.90		$3.56
	The dividend yield assumption is based on anticipated dividend payouts. The risk-free interest rate assumption is based on the United States Treasury yield curve at the grant date with maturity dates approximately equal to the expected life at the grant date. The Company estimates the expected volatility and expected option life assumption consistent with ASC Topic 718, Compensation - Stock Compensation. Expected volatility is based upon an analysis of historical prices of similar market capitalized trucking group participants within the Dow Jones Total United States Market Index over the expected term of the options. The Company chose a daily measurement interval for historical volatility as it believes this better depicts the nature of employee option exercise decisions being based on shorter-term trends in the price of the underlying shares, rather than on monthly price movements. As a result of the inability to predict the expected future employee exercise behavior, the Company estimated the expected term of the options using a simplified method based on contractual and vesting terms of the options. The Company uses historical data to estimate pre-vesting option forfeitures and records stock-based compensation expense only for those awards that are expected to vest.
	The following table summarizes stock option exercise information for the years presented (in thousands, except share data):
	2014				2013				2012
Number of stock options exercised	1,100,998				1,210,184				24,427
Intrinsic value of stock options exercised	$	15,830			$	8,773			$	25
Cash received upon exercise of stock options	$	11,488			$	12,985			$	268
Income tax benefit (deficiency)	$	3,730			$	187			$	(370	)
The following table is a rollforward of the Company's nonvested stock options:
	Stock Options
	Shares			Weighted Average Fair Value
Nonvested at January 1, 2014	1,606,588			$	4.66
Granted	175,142			6.79
Vested	(706,613	)		4.46
Forfeited	(86,779	)		3.88
Nonvested at December 31, 2014	988,338			$	4.02
The total fair value of the shares vested during the years ended December 31, 2014, 2013 and 2012 was $3.2 million, $4.0 million and $10.0 million, respectively.
Restricted Stock Awards
Restricted stock awards are shares of Swift's Class A common stock that are subject to forfeiture until the lapse of defined restrictions, including time-based restrictions. Restricted stock awards, which are granted in the form of restricted stock shares and RSUs, are accounted for as equity awards. Accordingly, the estimated fair value of restricted stock awards is based upon the closing price of the Company’s Class A common stock on the grant date.
Restricted Stock Share — This is typically the form of restricted stock award granted to the board of directors. Directors on the board are entitled to vote during the vesting period. For awards granted in 2014, the forfeiture restrictions associated with restricted stock shares lapse on the first anniversary of the grant date with respect to an equal installment of shares. For awards granted prior to 2014, the forfeiture restrictions associated with restricted stock shares lapse on each of the first three anniversaries of the grant date with respect to an equal installment of shares. Additionally, restricted stock shares are not transferable for a period of four years from the grant date, other than for applicable tax withholdings.
RSU — This is typically the form of restricted stock award granted to Company employees. An RSU represents a right to receive a common share of stock when the unit vests. RSU recipients cannot vote during the vesting period. They forfeit their units if their employment terminates before the vesting date.
The following table presents grants of restricted stock awards and the respective plans under which they were granted:
	2014			2013			2012
	(2014 Plan)			(2007 Plan)
Restricted stock shares granted to the board of directors	17,102			10,480			11,676
RSUs granted to company employees	203,968			254,533			—
Total restricted stock awards granted	221,070			265,013			11,676
The following table is a rollforward of nonvested restricted stock awards:
	Restricted Stock Awards
	Number of Awards			Weighted Average Fair Value
Nonvested at January 1, 2014	272,156			$	16.2
Granted	221,070			23.24
Vested	(98,866	)		16.12
Forfeited	(20,051	)		19.87
Nonvested at December 31, 2014	374,309			$	19.95
Performance Shares
Beginning in 2013, the Company granted certain members of executive management performance shares. These awards provide each grantee a number of shares of Swift's Class A common stock at the end of a three-year period, based on certain performance criteria established by the compensation committee of the board of directors. The performance criteria are designed to focus management's attention on the Company's key long-term financial goals, and are measured over the three-year period.
The following table is a rollforward of nonvested performance shares:
	Performance Shares
	Shares			Weighted Average Fair Value
Nonvested at January 1, 2014	101,366			$	13.36
Granted	68,026			$	23.3
Vested	—			$	—
Forfeited	(3,452	)		$	23.3
Nonvested at December 31, 2014	165,940			$	17.23
2012 Employee Stock Purchase Plan
In 2012, the Company’s board of directors adopted and its stockholders approved the Swift Transportation Company 2012 ESPP. The 2012 ESPP is intended to qualify under Section 423 of the Internal Revenue Code and is considered noncompensatory. Pursuant to the 2012 ESPP, the Company is authorized to issue up to 2 million shares of its Class A common stock to eligible employees who participate in the plan. Employees are eligible to participate in the 2012 ESPP following at least 90 days of employment with the Company or any of its participating subsidiaries. Under the terms of the 2012 ESPP, eligible employees may elect to purchase common stock through payroll deductions, not to exceed 15% of their gross cash compensation. The purchase price of the common stock is 95% of the common stock’s fair market value quoted on the NYSE on the last trading day of each offering period. There are four three-month offering periods corresponding to the calendar quarters. Each eligible employee is restricted to purchasing a maximum of $6,250 of common stock during an offering period, determined by the fair market value of the common stock as of the first day of the offering period, and $25,000 of common stock during a calendar year. Employees who own 5% or more of the total voting power or value of all classes of common stock are restricted from participating in the 2012 ESPP.
During the year ended December 31, 2014, the Company issued 50,788 shares, under the 2012 ESPP at an average price per share of $21.96. As of December 31, 2014, the Company is authorized to issue an additional 1.9 million shares under the 2012 ESPP.
Central's Stockholder Loans Receivable, Pre-acquisition
Upon closing of the Central Acquisition on August 6, 2013, Central's majority stockholder repaid $30.0 million on an unsecured promissory note to Central that was originally loaned on March 8, 2013.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	Income tax expense (benefit) was (in thousands):
		2014			2013			2012
	Current expense (benefit):
	Federal	$	81,117		$	(224	)	$	9,913
	State	8,861			5,143			3,148
	Foreign	4,107			1,530			1,949
		94,085			6,449			15,010
	Deferred expense (benefit):
	Federal	(4,189		)	85,512			47,501
	State	1,975			4,273			(2,010		)
	Foreign	(2,397		)	4,748			1,113
		$	(4,611	)	94,533			46,604
	Income tax expense	$	89,474		$	100,982		$	61,614
	The Company’s effective tax rate was 35.7%, 39.4% and 30.5%, for the years ended December 31, 2014, 2013 and 2012, respectively. Expected tax expense is computed by applying the United States federal corporate income tax rate of 35.0% to earnings before income taxes. Actual tax expense differs from expected tax expense as follows (in thousands):
		2014			2013			2012
	Computed “expected” tax expense	$	87,719		$	89,742		$	70,595
	Increase (decrease) in income taxes resulting from:
	State income taxes, net of federal income tax benefit	6,866			6,912			6,627
	Central pre-affiliation earnings taxed as S-Corp	—			(4,986		)	(9,118		)
	State tax rate change in deferred items	40			711			(6,414		)
	Foreign tax rate change in deferred items	—			5,023			—
	Effect of providing taxes on mark-to-market adjustment of derivatives recorded in AOCI	—			—			1,785
	Other	(5,151		)	3,580			(1,861		)
	Income tax expense	$	89,474		$	100,982		$	61,614
	The components of the net deferred tax asset (liability) were (in thousands):
		December 31,
		2014			2013
	Deferred tax assets:
	Self-insurance accruals	$	61,305		$	49,810
	Allowance for doubtful accounts	9,561			6,968
	Derivative financial instruments	2,350			4,537
	Vacation accrual	4,342			3,899
	Minimum tax credit	—			5,061
	Net operating loss	2,507			4,529
	Amortization of stock options	9,598			10,782
	Other	16,040			17,259
	Total deferred tax assets	105,703			102,845
	Valuation allowance	—			—
	Total deferred tax assets, net	105,703			102,845
	Deferred tax liabilities:
	Property and equipment, principally due to differences in depreciation	(401,963		)	(393,239		)
	Prepaid taxes, licenses and permits deducted for tax purposes	(13,170		)	(12,897		)
	Cancellation of debt	(7,503		)	(9,401		)
	Intangible assets	(115,115		)	(119,567		)
	Other	(5,345		)	(7,354		)
	Total deferred tax liabilities	(543,096		)	(542,458		)
	Net deferred tax liability	$	(437,393	)	$	(439,613	)
	These amounts are presented in the consolidated balance sheets in the indicated captions, except the current deferred tax liability which is included in accrued liabilities (in thousands):
		December 31,
		2014			2013
	Current deferred tax asset	$	44,861		$	46,833
	Current deferred tax liability	(1,614		)	(2,246		)
	Noncurrent deferred tax liability	(480,640		)	(484,200		)
	Net deferred tax liability	$	(437,393	)	$	(439,613	)
	As of December 31, 2014, the Company had federal and state net operating loss carryforwards remaining, with estimated tax effects of $0.4 million and $2.1 million, respectively. The federal and state net operating losses will expire at various times between 2015 and 2030. The Company has not established a valuation allowance as it has been determined that, based upon available evidence, a valuation allowance is not required. Management asserts that it is more likely than not that the results of future operations witll generate sufficient taxable income to realize the deferred tax assets. All other deferred tax assets are expected to be realized and utilized by continued profitability in future periods.
	United States income and foreign withholding taxes have not been provided on approximately $15.8 million of cumulative undistributed earnings of foreign subsidiaries. The earnings are considered to be permanently reinvested outside the United States. As such, the Company is not required to provide United States income taxes on these earnings until they are repatriated in the form of dividends or otherwise.
	The Company's unrecognized tax benefits as of December 31, 2014 would favorably impact our effective tax rate if subsequently recognized. The following is a rollforward of our unrecognized tax benefits (in thousands):
		2014			2013			2012
	Unrecognized tax benefits at beginning of year	$	2,385		$	2,385		$	2,332
	Increases for tax positions taken prior to beginning of year	95			—			149
	Decreases for tax positions taken prior to beginning of year	(741		)	—			(53		)
	Settlements	—			—			(43		)
	Unrecognized tax benefits at end of year	$	1,739		$	2,385		$	2,385
During the year ended December 31, 2014, the Company concluded its California examination, as well as various other state examinations for certain of its subsidiaries during the years ended December 31, 2014, 2013 and 2012. The conclusion of these examinations resulted in $0.8 million of additional tax payments and $0.4 million of interest and penalties during 2014. Additional tax payments, as well as interest and penalties related to these tax examinations were immaterial in 2013 and 2012. Other state jurisdictions are currently conducting examinations for years ranging from 2010 to 2013. At the completion of these examinations, management does not expect any adjustments that would have a material impact on the Company’s effective tax rate. Years subsequent to 2010 remain subject to examination.
The Company recognizes potential accrued interest and penalties related to unrecognized tax benefits as a component of income tax expense. Accrued interest and penalties as of December 31, 2014, 2013 and 2012, were approximately $1.3 million, $1.5 million and $1.3 million, respectively. To the extent interest and penalties are not assessed with respect to uncertain tax positions, amounts accrued will be reduced and reflected as a reduction of the overall income tax provision.
The Company does not anticipate a decrease of unrecognized tax benefits during the next twelve months.

Employee_Benefit_Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plan	Employee Benefits
	The Company maintains a 401(k) benefit plan available to all employees who are 21 years of age or older and have completed six months of service. Under the plan, the Company has the option to match employee discretionary contributions up to 3% of an employee’s compensation. Employees’ rights to employer contributions vest after five years from their date of employment.
	For the years ended December 31, 2014, 2013 and 2012, the Company’s employee benefits expense for matching contributions was approximately $4.7 million, $5.5 million and $5.6 million, respectively. As of December 31, 2014 and 2013, the Company owed $4.9 million and $4.4 million in matching contributions, respectively, to the plan in respect of such matching contributions.

Key_Customer

Key Customer	12 Months Ended
	Dec. 31, 2014
Risks and Uncertainties [Abstract]
Key Customer	Key Customer
	Services provided to the Company’s largest customer, Wal-Mart, generated 11.0%, 10.8% and 11.4% of operating revenue in 2014, 2013 and 2012, respectively. Operating revenue generated by Wal-Mart is reported in the Truckload, Dedicated, Central Refrigerated and Intermodal operating segments. No other customer accounted for 10% or more of operating revenue in the reporting period.

Fair_Value_Measurement

Fair Value Measurement	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurement	Fair Value Measurement
	ASC Topic 820, Fair Value Measurements and Disclosures, requires that the Company disclose estimated fair values for its financial instruments. The estimated fair value of a financial instrument is the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date in the principal or most advantageous market for the asset or liability. Fair value estimates are made at a specific point in time and are based on relevant market information and information about the financial instrument. These estimates do not reflect any premium or discount that could result from offering for sale at one time the Company’s entire holdings of a particular financial instrument. Changes in assumptions could significantly affect these estimates. Because the fair value is estimated as of December 31, 2014 and 2013, the amounts that will actually be realized or paid at settlement or maturity of the instruments in the future could be significantly different.
	The tables below exclude certain financial instruments. The excluded financial instruments are as follows: cash and cash equivalents, restricted cash, accounts receivable, net, income tax refund receivable and accounts payable. The estimated fair value of these financial instruments approximate carrying value as they are short-term in nature. Additionally, for notes payable under revolving lines of credit, fair value approximates the carrying value due to the variable interest rate. For capital leases, the carrying value approximates the fair value. The table below also excludes financial instruments reported at estimated fair value on a recurring basis. See “Recurring Fair Value Measurements.” All remaining balance sheet amounts excluded from the table below are not considered financial instruments subject to this disclosure.
	The following table presents the carrying amounts and estimated fair values of the Company’s financial instruments (in thousands):
			December 31,
			2014						2013
			Carrying			Estimated			Carrying			Estimated
			Value			Fair Value			Value			Fair Value
	Financial Assets:
	Restricted investments		$	24,510		$	24,502		$	25,814		$	25,808
	Financial Liabilities:
	2014 Agreement: Term Loan A		500,000			500,000			—			—
	2014 Agreement: Term Loan B		396,080			390,436			—			—
	2013 Agreement: Term Loan B-1		—			—			229,000			230,031
	2013 Agreement: Term Loan B-2		—			—			410,000			412,358
	Senior Notes		—			—			493,825			549,059
	Securitization of accounts receivable		334,000			334,000			264,000			264,000
	The carrying amounts shown in the table (other than the restricted investments, and the securitization of accounts receivable) are included in the consolidated balance sheets in long-term debt. The estimated fair values of the financial instruments shown in the above table as of December 31, 2014 and 2013, represent management’s best estimates of the amounts that would be received to sell those assets or that would be paid to transfer those liabilities in an orderly transaction between market participants at that date. The estimated fair value measurements maximize the use of observable inputs. However, in situations where there is little, if any, market activity for the asset or liability at the measurement date, the estimated fair value measurement reflects the Company’s own judgments about the assumptions that market participants would use in pricing the asset or liability. These judgments are developed by the Company based on the best information available under the circumstances.
	The following summary presents a description of the methods and assumptions used to estimate the fair value of each class of financial instrument.
	Restricted Investments — The estimated fair value of the Company’s restricted investments is based on quoted prices in active markets that are readily and regularly obtainable.
	Term Loans and Senior Notes — The estimated fair values of the Term Loan B and Senior Notes were determined by bid prices in trades between qualified institutional buyers.
	Securitization of Accounts Receivable — The Company’s securitization of accounts receivable consists of borrowings outstanding pursuant to the Company’s 2013 RSA and 2011 RSA as of December 31, 2014 and 2013, respectively, as discussed in Note 11. Its fair value is estimated by discounting future cash flows using a discount rate commensurate with the uncertainty involved.
	Derivative Financial Instruments — As of December 31, 2014, interest rate swaps represent the only major category of assets or liabilities included in the consolidated balance sheets that are measured by estimating fair value on a recurring basis. The fair values of the interest rate swaps are based on valuations provided by third parties, derivative pricing models, and credit spreads derived from the trading levels of the Company’s first lien term loan as of December 31, 2014 and 2013. The Company’s interest rate swaps are not actively traded, but are valued using valuation models and credit valuation adjustments, both of which use significant inputs that are observable in active markets over the terms of the instruments the Company holds, and accordingly, the Company classified these valuation techniques as Level 2 in the hierarchy. Interest rate yield curves and credit spreads derived from trading levels of the Company’s first lien term loan are the significant inputs into these valuation models. These inputs are observable in active markets over the terms of the instruments the Company holds. The Company considers the effect of its own credit standing and that of its counterparties in the valuations of its derivative financial instruments.
	Fair Value Hierarchy — ASC Topic 820 establishes a framework for measuring fair value in accordance with US-GAAP and expands financial statement disclosure requirements for fair value measurements. ASC Topic 820 further specifies a hierarchy of valuation techniques, which is based on whether the inputs into the valuation technique are observable or unobservable. The hierarchy is as follows:
	•	Level 1 — Valuation techniques in which all significant inputs are quoted prices from active markets for assets or liabilities that are identical to the assets or liabilities being measured.
	•	Level 2 — Valuation techniques in which significant inputs include quoted prices from active markets for assets or liabilities that are similar to the assets or liabilities being measured and/or quoted prices from markets that are not active for assets or liabilities that are identical or similar to the assets or liabilities being measured. Also, model-derived valuations in which all significant inputs and significant value drivers are observable in active markets are Level 2 valuation techniques.
	•	Level 3 — Valuation techniques in which one or more significant inputs or significant value drivers are unobservable. Unobservable inputs are valuation technique inputs that reflect the Company’s own assumptions about the assumptions that market participants would use in pricing an asset or liability.
	When available, the Company uses quoted market prices to determine the estimated fair value of an asset or liability. If quoted market prices are not available, the Company will measure fair value using valuation techniques that use, when possible, current market-based or independently-sourced market parameters, such as interest rates and currency rates. The level in the fair value hierarchy within which a fair measurement in its entirety falls is based on the lowest level input that is significant to the estimated fair value measurement in its entirety.
	Recurring Fair Value Measurements — As of December 31, 2014 and 2013, no assets of the Company were measured at estimated fair value on a recurring basis. As of December 31, 2014 and 2013, information about inputs into the estimated fair value measurements of each major category of the Company’s liabilities that were measured at estimated fair value on a recurring basis in periods subsequent to their initial recognition was as follows (in thousands):
					Fair Value Measurements at Reporting Date Using
		Estimated			Level 1 Inputs			Level 2 Inputs			Level 3 Inputs
		Fair Value
	As of December 31, 2014
	Interest rate swaps	$	6,109		$	—		$	6,109		$	—
	As of December 31, 2013
	Interest rate swaps	$	11,768		$	—		$	11,768		$	—
	Nonrecurring Fair Value Measurements — As of December 31, 2013, none of the Company's assets were measured at estimated fair value on a nonrecurring basis. The following table presents assets measured at estimated fair value on a nonrecurring basis, as of December 31, 2014 (in thousands):
					Fair Value Measurements at Reporting Date Using
		Estimated Fair Value			Level 1 Inputs			Level 2 Inputs			Level 3 Inputs			Total Gains (Losses)
	As of December 31, 2014
	Other assets (1)	$	—		$	—		$	—		$	—		$	(2,308	)
	____________
	-1	During 2014, certain operations software was replaced and the carrying value was determined to be fully impaired.

Intangible_Assets

Intangible Assets	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	Intangible Assets
	Intangible asset balances were as follows (in thousands):
		December 31,
		2014			2013
	Customer Relationship:
	Gross carrying value	$	275,324		$	275,324
	Accumulated amortization	(156,428		)	(139,614		)
	Trade Name:
	Gross carrying value	181,037			181,037
	Intangible assets, net	$	299,933		$	316,747
	In conjunction with the 2007 Transactions, definite-lived intangible assets with a gross carrying value of $261.2 million were recorded. The related amortization comprised $15.6 million in 2014, $15.6 million in 2013, and $15.8 million in 2012 of total amortization of intangibles. Amortization of intangibles also included $1.2 million each year related to intangible assets existing prior to the 2007 Transactions. Management anticipates that the composition and amount of amortization associated with intangible assets as of December 31, 2014 will remain consistent at $16.8 million through 2017, and will decrease to $16.3 million in 2018, of which $0.6 million will represent the final amortization of the intangible assets existing prior to the 2007 Transactions. Actual amounts of amortization expense may differ from estimated amounts due to additional intangible asset acquisitions, impairment of intangible assets, accelerated amortization of intangible assets and other events.

Goodwill

Goodwill	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Goodwill
	The following presents the components of goodwill by reportable segment as of December 31, 2014 and 2013 (in thousands):
		Gross Carrying Amount		Accumulated Impairment Losses			Net Carrying Amount
	Truckload	$	376,998	$	(190,394	)	$	186,604
	Dedicated	130,742		(64,090		)	66,652
	Total	$	507,740	$	(254,484	)	$	253,256
	There were no impairments identified during annual goodwill impairment testing in 2014, 2013 or 2012.

Earnings_Loss_Per_Share

Earnings (Loss) Per Share	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Earnings per Share	Earnings per Share
	Basic and diluted earnings per share, as presented in the consolidated income statements, are calculated by dividing net income by the respective weighted average common shares outstanding during the period.
	The following table reconciles basic weighted average shares outstanding to diluted weighted average shares outstanding (in thousands):
		2014	2013	2012
	Basic weighted average common shares outstanding	141,431	140,179	139,532
	Dilutive effect of stock options	2,044	2,042	87
	Diluted weighted average common shares outstanding	143,475	142,221	139,619
	Anti-dilutive shares excluded from diluted earnings per share (1)	162	174	4,356
	____________
	-1	The impact of certain outstanding options to purchase shares of the Company’s Class A common stock were anti-dilutive because the options' exercise prices were greater than the average market prices of the common shares. These anti-dilutive shares were excluded from the calculation of diluted earnings per share.

Quarterly_Result_Of_Operations

Quarterly Result Of Operations (unaudited)	12 Months Ended
	Dec. 31, 2014
Selected Quarterly Financial Information [Abstract]
Quarterly Results of Operations (unaudited)	Quarterly Results of Operations (Unaudited)
	In management's opinion, the following summarized financial information fairly presents the Company's results of operations for the quarters noted. These results are not necessarily indicative of future quarterly results.
		First Quarter		Second Quarter		Third Quarter		Fourth Quarter
		(In thousands, except per share data)
	2014:00:00
	Operating revenue	$	1,008,446	$	1,075,898	$	1,074,880	$	1,139,500
	Operating income	46,170		94,022		97,411		132,467
	Net income	12,305		40,198		50,158		58,491
	Basic earnings per share	0.09		0.28		0.35		0.41
	Diluted earnings per share	0.09		0.28		0.35		0.41
	2013:00:00
	Operating revenue (1)	$	981,608	$	1,029,071	$	1,032,127	$	1,075,389
	Operating income (1)	69,718		100,266		84,420		102,555
	Net income (1)	30,292		49,879		29,953		45,298
	Basic earnings per share (1)	0.22		0.36		0.21		0.32
	Diluted earnings per share (1)	0.21		0.35		0.21		0.32
	____________
	-1	The first and second quarter results of 2013 have been recast due to the acquisition of Central. Refer to Note1 for further information regarding the acquisition.

Segment_Information

Segment Information	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Segment Information	Segments and Geography
	Segment Information
	During 2014, we operated four reportable segments: Truckload, Dedicated, Central Refrigerated and Intermodal. In the first quarter of 2014, the Company reorganized its reportable segments to reflect management’s revised reporting structure of its lines of business following the integration of Central. In association with the operational reorganization, the operations of Central's TOFC business are reported within the Company's Intermodal segment and the operations of Central's logistics business, third-party leasing, and other services provided to owner-operators are reported in the Company's other non-reportable segment. All prior period historical results related to the above noted segment reorganization have been retrospectively recast.
	Truckload — The truckload segment consists of one-way movements over irregular routes throughout the United States, Mexico, and Canada. This service utilizes both company and owner-operator tractors with dry van, flatbed, and other specialized trailing equipment.
	Dedicated — Through the dedicated segment, the Company devotes use of equipment to specific customers and offers tailored solutions under long-term contracts. This dedicated segment utilizes refrigerated, dry van, flatbed and other specialized trailing equipment.
	Central Refrigerated — This segment represents the core operations of Central and primarily consists of shipments for customers that require temperature-controlled trailers. These shipments include one-way movements over irregular routes, as well as dedicated truck operations.
	Intermodal — The intermodal segment includes revenue generated by moving freight over the rail in the Company's containers and other trailing equipment, combined with revenue for drayage to transport loads between the railheads and customer locations.
	Other Non-reportable Segment — The other non-reportable segment includes the Company's logistics and freight brokerage services, as well as support services provided by its subsidiaries to customers and owner-operators, including repair and maintenance shop services, equipment leasing, and insurance. Intangible amortization related to the 2007 going-private transaction is also included in this other non-reportable segment.
	Other Intersegment Transactions — Certain operating segments provide transportation and related services for other affiliates outside their reportable segment. Revenues for such services are based on negotiated rates, which we believe approximate fair value, and are reflected as revenues of the billing segment. These rates are adjusted from time to time based on market conditions. Such intersegment revenues and expenses are eliminated in our consolidated results.
	Set forth in the tables below is certain financial information with respect to the Company’s segments (in thousands):
		Operating Revenue
		2014			2013			2012
	Truckload	$	2,301,010		$	2,313,035		$	2,282,342
	Dedicated	892,078			738,929			724,405
	Central Refrigerated	417,980			452,531			415,733
	Intermodal	401,577			376,075			355,494
	Subtotal	4,012,645			3,880,570			3,777,974
	Non-reportable segment	342,969			287,853			268,821
	Intersegment eliminations	(56,890		)	(50,228		)	(70,710		)
	Consolidated operating revenue	$	4,298,724		$	4,118,195		$	3,976,085
		Operating Income (Loss)
		2014			2013			2012
	Truckload	$	258,072		$	225,963		$	246,005
	Dedicated	75,794			83,520			74,026
	Central Refrigerated	14,035			17,682			21,334
	Intermodal	8,298			5,619			(6,486		)
	Subtotal	356,199			332,784			334,879
	Non-reportable segment	13,871			24,175			16,937
	Consolidated operating income	$	370,070		$	356,959		$	351,816
		Depreciation and Amortization Expense
		2014			2013			2012
	Truckload	$	113,875		$	127,404		$	121,004
	Dedicated	53,682			45,568			44,088
	Central Refrigerated	12,510			13,926			14,539
	Intermodal	10,875			9,268			9,209
	Subtotal	190,942			196,166			188,840
	Non-reportable segment	30,180			29,842			29,999
	Consolidated depreciation and amortization expense	$	221,122		$	226,008		$	218,839
	Geographical Information
	In aggregate, operating revenue from the Company's foreign operations was less than 5.0% of consolidated operating revenue for each of the years ended December 31, 2014, 2013 and 2012. Additionally, long-lived assets on the balance sheets of the Company's foreign subsidiaries were less than 5.0% of consolidated Total assets as of December 31, 2014 and 2013.

Settlement_City_of_Los_Angeles

Settlement- City of Los Angeles	12 Months Ended
	Dec. 31, 2014
Disclosure Settlement City Of Los Angeles [Abstract]
Settlement-City Of Los Angeles	Settlement - City of Los Angeles
	Effective March 2, 2012, the Company and the City of Los Angeles (the “City”) entered into the Settlement Agreement and Mutual Release of Claims (“Settlement”). The Settlement was associated with the Incentive Addendum to Drayage Services Concession Agreement entered into by the Company and the City in December 2008 and as amended, in June 2009 (collectively the “Amended Addendum”). Pursuant to the Amended Addendum, in 2008 the Company received a one-time, early commitment incentive based on a minimum number of required drays to be completed by the Company over a five-year term. The Company initially recorded the incentive as deferred revenue, and at the time of the Settlement, the Company had approximately $9.2 million remaining as deferred revenue. Concurrent with the City’s and the Company’s execution of the Settlement and the corresponding termination of the Amended Addendum, the Company refunded the City $4.0 million in full satisfaction of its obligations under the Amended Addendum and in full and final settlement of all claims for payment and damages that may be alleged by the City under the Amended Addendum. The remaining $5.2 million recorded as deferred revenue was recognized into income and classified as a reduction of operating supplies and expenses in the Company’s consolidated income statements.

Description_of_Business_and_Ba1

Description of Business and Basis of Presentation Basis of Presentation Policy (Policies)	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Consolidation, Policy [Policy Text Block]	Basis of Presentation
	General — The accompanying consolidated financial statements include the accounts of Swift Transportation Company and its wholly-owned subsidiaries. All significant intercompany balances and transactions have been eliminated in preparing the consolidated financial statements. When the Company does not have a controlling interest in an entity, but exerts significant influence over the entity, the Company applies the equity method of accounting.
Basis of Accounting, Policy [Policy Text Block]	In management's opinion, the accompanying financial statements were prepared in accordance with principles generally accepted in the United States and include all adjustments necessary for the fair presentation of the periods presented.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Derivatives, Policy [Policy Text Block]	Derivative Instruments — All financial derivative instruments are recorded on our consolidated balance sheets at estimated fair value. Derivatives not designated as hedges are adjusted to fair value through the Company’s consolidated income statements. Depending on the nature of a derivative that is designated as a hedge, effective changes in its fair value either offset the change in fair value of the hedged assets, liabilities or firm commitments through the Company’s consolidated income statements, or are recorded in AOCI until the hedged item is recorded in the Company’s consolidated income statements. Any portion of a change in a derivative's estimated fair value that is considered to be ineffective, or is excluded from the measurement of effectiveness, is recorded immediately in income.
Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block]	Intangible Assets other than Goodwill — The Company’s intangible assets other than goodwill primarily consist of acquired customer relationships and trade names. Amortization of acquired customer relationships is calculated on the 150% declining balance method over the estimated useful life of 15 years. The customer relationship contributed to the Company at May 9, 2007 is amortized over 15 years on a straight-line basis. The trade name has an indefinite useful life and is not amortized, but rather is tested for impairment at least annually, unless events occur or circumstances change between annual tests that would more likely than not reduce the fair value.
	Management reviews its intangible assets for impairment whenever events or circumstances indicate that the carrying amount of the asset may not be recoverable, in accordance with ASC Topic 350, Intangibles-Goodwill and Other. When such events or changes in circumstances occur, management performs a recoverability test that compares the carrying amount with the projected undiscounted cash flows from the use and eventual disposition of the asset or asset group. An impairment is recorded for any excess of the carrying amount over the estimated fair value, which is generally determined using discounted future cash flows.
Income Tax, Policy [Policy Text Block]	Income Taxes — Management accounts for income taxes under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to operating loss and tax credit carryforwards, as well as differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. The effect on deferred tax assets and liabilities of changes in tax rates is recognized in income in the period that includes the enactment date.
	A valuation allowance is provided against deferred tax assets if the Company determines it is more likely than not that such assets will not ultimately be realized.
	The Company does not recognize a tax benefit for uncertain tax positions unless it concludes that it is more likely than not that the benefit will be sustained on audit by the taxing authority based solely on the technical merits of the associated tax position. If the recognition threshold is met, the Company recognizes a tax benefit measured at the largest amount of the tax benefit that, in the management's judgment, is greater than 50% likely to be realized. The Company records interest and penalties related to unrecognized tax positions in income tax expense.
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents — The Company considers all highly liquid debt instruments purchased with original maturities of three months or less to be cash equivalents.
	Restricted Cash — The Company’s wholly-owned captive insurance companies, Red Rock and Mohave, maintain certain operating bank accounts, working trust accounts and investment accounts. The cash and short-term investments within the accounts are restricted by insurance regulations to fund the insurance claim losses to be paid by the captive insurance companies. Therefore, these cash and short-term investments are classified as restricted cash in the consolidated balance sheets.
Property, Plant and Equipment, Policy [Policy Text Block]	Property and Equipment — Property and equipment are stated at cost. Costs to construct significant assets include capitalized interest incurred during the construction and development period. Expenditures for replacements and improvements are capitalized. Maintenance and repairs are expensed as incurred. Depreciation on property and equipment is calculated on a straight-line basis over the estimated useful lives of 5 to 40 years for facilities and improvements, 3 to 20 years for revenue and service equipment and 3 to 5 years for furniture and office equipment. Net gains on the disposal of property and equipment are presented in the consolidated income statements within operating income.
	Tires on revenue equipment purchased are capitalized as a component of the related equipment cost when the vehicle is placed in service and depreciated over the life of the vehicle. Replacement tires are classified as inventory and expensed when placed in service.
	Management evaluates its property and equipment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable in accordance with ASC Topic 360, Property, Plant and Equipment. When such events or changes in circumstances occur, management performs a recoverability test that compares the carrying amount with the projected undiscounted cash flows from the use and eventual disposition of the asset or asset group. An impairment is recorded for any excess of the carrying amount over the estimated fair value, which is generally determined using discounted future cash flows. Fair value is determined through various valuation techniques including discounted cash flow models, quoted market values and third-party independent appraisals, as considered necessary.
Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]	Goodwill — Management evaluates goodwill on an annual basis as of November 30th, or more frequently if indicators of impairment exist. The Company assesses qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than the carrying amount. If the Company concludes that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, the Company conducts a two-step quantitative goodwill impairment test. The first step of the impairment test involves comparing the fair values of the applicable reporting units with their carrying values. Management estimates the fair values of its reporting units using a combination of the income and market approaches. If the carrying amount of a reporting unit exceeds the reporting unit’s fair value, then management performs the second step of the goodwill impairment test. The second step of the goodwill impairment test involves comparing the implied fair value of the affected reporting unit’s goodwill with the carrying value of that goodwill. Any amount by which the carrying value of the goodwill exceeds its implied fair value is recognized as an impairment loss. Refer to Note 24 for discussion of the results of the Company's annual evaluation as of November 30, 2014.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates — The preparation of the consolidated financial statements, in accordance with US-GAAP, requires management to make estimates and assumptions about future events that affect the amounts reported in the Company’s consolidated financial statements and accompanying notes. On an ongoing basis, management evaluates and periodically adjusts its estimates and assumptions, based on historical experience, the impact of the current economic environment, and other key factors. Volatile energy markets, as well as changes in consumer spending have increased the inherent uncertainty in such estimates and assumptions. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates. Significant items subject to such estimates and assumptions include:
	•	carrying amount of property and equipment, intangibles and goodwill;
	•	valuation allowances for receivables, inventories and deferred income tax assets;
	•	valuation of financial instruments;
	•	calculation of share-based compensation;
	•	estimates of claims accruals; and
	•	contingent obligations.
Revenue Recognition, Policy [Policy Text Block]	Revenue Recognition — The Company recognizes operating revenues and the related direct costs of such revenue as of the date the freight is delivered, in accordance with ASC Topic 605-20-25-13, Services for Freight-in-Transit at the End of a Reporting Period.
	The Company recognizes operating lease revenue from leasing tractors and related equipment to owner-operators. Operating lease revenue from rental operations is recognized as earned, which is straight-lined per the rent schedules in the lease agreements. Losses from lease defaults are recognized as offsets to revenue in the amount of earned, but not collected revenue.
Inventory, Policy [Policy Text Block]	Inventories and Supplies — Inventories and supplies consist primarily of spare parts, tires, fuel and supplies and are stated at lower of cost or market. Cost is determined using the first-in, first-out method.
Marketable Securities, Held-to-maturity Securities, Policy [Policy Text Block]	Restricted Investments — The Company accounts for its investments in accordance with ASC Topic 320, Investments - Debt and Equity Securities. Management determines the appropriate classification of its investments in debt securities at the time of purchase and re-evaluates the determination on a quarterly basis. As of December 31, 2014, all of the Company’s investments in fixed-maturity securities were classified as held-to-maturity, as the Company has the positive intent and ability to hold these securities to maturity. Held-to-maturity securities are carried at amortized cost. The amortized cost of debt securities is adjusted using the effective interest rate method for amortization of premiums and accretion of discounts. Amortization and accretion is reported in other (income) expenses in the Company’s consolidated income statements.
	Management periodically evaluates restricted investments for impairment. The assessment of whether impairments have occurred is based on management’s case-by-case evaluation of the underlying reasons for the decline in estimated fair value. Management accounts for other-than-temporary impairments of debt securities using the provisions of Topic 320, Investments – Debt and Equity Securities, related to the recognition of other-than-temporary impairments of debt securities. This guidance requires the Company to evaluate whether it intends to sell an impaired debt security or whether it is more likely than not that it will be required to sell an impaired debt security before recovery of the amortized cost basis. If either of these criteria are met, an impairment equal to the difference between the debt security’s amortized cost and its estimated fair value is recognized in earnings. For impaired debt securities that do not meet these criteria, the Company determines if a credit loss exists with respect to the impaired security. If a credit loss exists, the credit loss component of the impairment (i.e., the difference between the security’s amortized cost and the present value of projected future cash flows expected to be collected) is recognized in earnings and the remaining portion of the impairment is recognized as a component of AOCI.
Segment Reporting, Policy [Policy Text Block]	Segments — The Company uses the “management approach” to determine its reportable segments, as well as to determine the basis of reporting the operating segment information. The management approach focuses on financial information that management uses to make operating decisions. The chief operating decision makers use operating revenues, operating expense categories, operating ratios, operating income and key operating statistics to evaluate performance and allocate resources to the Company’s operations.
	Operating income is the measure of segment profit or loss management uses to evaluate segment performance and allocate resources, which is consistent with US-GAAP for segment reporting. It is the Company’s measure of segment performance. Operating income should not be viewed as a substitute for US-GAAP net income (loss). Management believes the presentation of operating income enhances the understanding of the Company's performance by highlighting the results of operations and the underlying profitability drivers of the business segments. Operating income is defined as operating revenues less operating expenses, before tax.
	Based on the unique nature of the Company's operating structure, revenue-generating assets are interchangeable between segments. Therefore, the Company does not prepare separate balance sheets by segment, as assets are not separately identifiable by segment. The Company allocates depreciation and amortization expense on its property and equipment to the segments based on the actual utilization of the asset by the segment during the period.
Self Insurance Reserve [Policy Text Block]	Claims Accruals — The Company is self-insured for a portion of its auto liability, workers’ compensation, property damage, cargo damage, and employee medical expense risk. This self-insurance results from buying insurance coverage that applies in excess of a retained portion of risk for each respective line of coverage. The Company accrues for the cost of the uninsured portion of pending claims by evaluating the nature and severity of individual claims and by estimating future claims development based upon historical claims development trends. The actual cost to settle our self-insured claim liabilities may differ from our reserve estimates due to legal costs, claims that have been incurred but not reported and various other uncertainties, including the inherent difficulty in estimating the severity of the claims and the potential judgment or settlement amount to dispose of the claim.
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]	Stock-based Compensation — The Company accounts for stock-based compensation expense using the modified prospective method under ASC Topic 718, Compensation - Stock Compensation. ASC Topic 718 requires that all share-based payments to employees and non-employee directors, including grants of employee stock options, be recognized in the financial statements based upon a grant-date fair value of an award. The Company calculates the number of awards expected to vest as awards granted, less expected forfeitures over the life of the award (estimated at grant date). Compensation expense is recorded based on amortization of the grant-date fair value over a graded vesting period. Unless a material deviation from the assumed forfeiture rate is observed during the term in which the awards are expensed, any adjustment necessary to reflect differences in actual experience is recognized in the period the award becomes payable or exercisable. See Note 17 for additional information relating to the Company’s stock compensation plan.

Recently_Issued_Accounting_Pro

Recently Issued Accounting Pronouncements (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Changes and Error Corrections [Abstract]
Description of New Accounting Pronouncements Not yet Adopted [Text Block]	Recently Issued Accounting Pronouncement
	In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, which established ASC Topic 606. The new revenue recognition standard eliminates all industry-specific guidance and provides a five-step analysis of transactions to determine when and how revenue is recognized. The premise of the guidance is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The amendments in this ASU will be effective for the Company beginning January 1, 2017, and may be applied retrospectively to each period presented, or as a cumulative effect adjustment as of the date of adoption. Early adoption is not permitted. Management is currently evaluating the accounting, transition and disclosure requirements of the standard and cannot currently estimate the financial statement impact of adoption.

Description_of_Business_and_Ba2

Description of Business and Basis of Presentation Central Acquisition (Tables)	12 Months Ended
	Dec. 31, 2012
Business Acquisition [Line Items]
Business Combination Disclosure [Text Block]	The following financial information as of, and for the year ended, December 31, 2012 has been recast to reflect the accounts of Central as if it was consolidated as of January 1, 2012 (in thousands, except per share data):
		31-Dec-12
		Swift			Central			Intercompany
		Transportation			Refrigerated			Elimination
		Company			Transportation Inc.			Entries			Total
	Total current assets	$	674,537		$	68,211		$	(657	)	$	742,091
	Total assets	2,632,178			160,560			(757		)	2,791,981
	Total current liabilities	323,293			60,813			(657		)	383,449
	Total liabilities	2,402,067			100,367			(657		)	2,501,777
	Total stockholders' equity	230,111			60,193			(100		)	290,204
		2012
		Swift			Central			Intercompany
		Transportation			Refrigerated			Elimination
		Company			Transportation Inc.			Entries			Total
	Operating revenue	$	3,493,182		$	484,657		$	(1,754	)	$	3,976,085
	Operating income	322,046			29,770			—			351,816
	Net income	114,589			25,498			—			140,087
	Basic earnings per share (1)	$	0.82		$	0.18		$	—		$	1
	Diluted earnings per share (1)	0.82			0.18			—			1
	Net cash provided by operating activities	$	406,556		$	40,562		$	—		$	447,118
	Net cash (used in) provided by investing activities	(172,499		)	3,370			—			(169,129		)
	Net cash used in financing activities	(262,545		)	(43,932		)	—			(306,477		)
	____________

Restricted_Investments_Tables

Restricted Investments (Tables)	12 Months Ended
	Dec. 31, 2014
Schedule of Investments [Abstract]
Amortized Cost, Gross Unrealized Gains And Losses, Estimated Fair Value Of Fixed Maturity Securities	The following table presents the cost or amortized cost, gross unrealized gains and losses, and estimated fair value of the Company’s restricted investments (in thousands):
		31-Dec-14
				Gross Unrealized
		Cost or Amortized Cost		Gains		Temporary			Estimated Fair Value
						Losses
	United States corporate securities	$	20,892	$	2	$	(10	)	$	20,884
	Foreign corporate securities	1,503		—		—			1,503
	Negotiable certificate of deposits	2,115		—		—			2,115
	Total restricted investments	$	24,510	$	2	$	(10	)	$	24,502
		December 31, 2013
				Gross Unrealized
		Cost or Amortized Cost		Gains		Temporary			Estimated Fair Value
						Losses
	United States corporate securities	$	20,197	$	2	$	(7	)	$	20,192
	Foreign corporate securities	3,502		—		—			3,502
	Negotiable certificate of deposits	2,115		—		(1		)	2,114
	Total restricted investments	$	25,814	$	2	$	(8	)	$	25,808

Accounts_Receivable_Tables

Accounts Receivable (Tables)	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Schedule of Accounts Receivable	Accounts receivable balances were as follows (in thousands):
		December 31,
		2014			2013
	Trade customers	$	457,823		$	392,233
	Equipment manufacturers	7,725			6,102
	Other	23,375			27,605
	Total accounts receivable	488,923			425,940
	Less: Allowance for doubtful accounts	(9,924		)	(7,504		)
	Accounts receivable, net	$	478,999		$	418,436
Schedule Of Allowance For Doubtful Accounts	The following schedule presents the rollforward of the allowance for doubtful accounts (in thousands):
		December 31,
		2014			2013			2012
	Beginning balance	$	7,504		$	7,432		$	6,617
	Provision	2,844			1,370			977
	Recoveries	89			35			103
	Write-offs	(513		)	(1,333		)	(265		)
	Ending balance	$	9,924		$	7,504		$	7,432

Assets_Held_For_Sale_Tables

Assets Held For Sale (Tables)	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Schedule Of Assets Held For Sale	Assets held for sale balances were (in thousands):
		December 31,
		2014		2013
	Land and facilities	$	288	$	14,627
	Revenue equipment	2,619		4,641
	Assets held for sale	$	2,907	$	19,268

Accrued_Liabilities_Tables

Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2014
Accrued Liabilities [Abstract]
Schedule of Accrued Liabilities	Accrued Liabilities
	The following table presents the composition of accrued liabilities (in thousands):
		December 31,
		2014		2013
	Employee compensation	$	50,398	$	56,427
	Owner-operator lease purchase reserve	10,418		10,335
	Income tax accrual	3,541		4,785
	Accrued owner-operator expenses	6,507		6,866
	Deferred revenue	1,504		484
	Fuel and property taxes	3,812		5,241
	Accrued interest expense	4,216		11,328
	Other	19,933		15,279
	Accrued liabilities	$	100,329	$	110,745

Notes_Receivable_Tables

Notes Receivable (Tables)	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Notes Receivable Included In Current Portion Of Notes Receivable And Other Assets	Notes Receivable
	Notes receivable are included in "Current portion of notes receivable" and "Other assets" in the consolidated balance sheets and were comprised of (in thousands):
		December 31,
		2014			2013
	Notes receivable due from owner-operators, with interest rates at 15%, secured by revenue equipment. Terms range from several months to three years	$	13,642		$	13,264
	Other	1,933			2,361
	Total notes receivable	15,575			15,625
	Less: current portion	(9,202		)	(7,210		)
	Long-term notes receivable	$	6,373		$	8,415

Claims_Accruals_Tables

Claims Accruals (Tables)	12 Months Ended
	Dec. 31, 2014
Claims Accruals (Tables) [Abstract]
Schedule of Claims Accruals	Claims accruals were comprised of the following (in thousands):
		December 31,
		2014			2013
	Auto and collision liability	$	112,548		$	102,462
	Workers’ compensation liability	82,439			70,145
	Owner-operator claims liability	13,233			8,610
	Group medical liability	12,064			9,946
	Cargo damage liability	4,660			2,888
	Claims accrual	224,944			194,051
	Less: current portion	(81,251		)	(75,469		)
	Long-term claim accruals	$	143,693		$	118,582

Accounts_Receivable_Securitiza1

Accounts Receivable Securitization Accounts Receivable Securitization (Tables)	12 Months Ended
	Dec. 31, 2014
Accounts Receivable Securitization Balances [Abstract]
Characteristics of Securitizations or Asset-backed Financing Arrangements that are Accounted for as Sale	The following table summarizes the key differences between the current and previous securitization programs (dollar amounts in thousands):
		2013 RSA		2011 RSA
	Effective	Jun-13		Jun-11
	Borrowing capacity (1)	$	375,000	$	275,000
	Final maturity date	July 13, 2016		June 8, 2014
	Unused commitment fee rate	35 basis points		40 basis points
	Program fees on outstanding balances	commercial paper rates + 95 basis points		commercial paper rates + 125 basis points
	____________
	(1) On September 26, 2014, the Company exercised an accordion option, increasing borrowing capacity on the 2013 RSA from $325.0 million to $375.0 million.

Debt_And_Financing_Transaction1

Debt And Financing Transactions (Tables)	12 Months Ended
	Dec. 31, 2014
Long-term Debt Outstanding [Abstract]
Schedule of Long-term Debt Instruments [Table Text Block]	The following tables present the key terms of the current and previous credit agreements (dollars in thousands):
	2014 Agreement		Term Loan A		Term Loan B		Revolver
	Maximum borrowing capacity		$500,000		$400,000		$450,000
	Final maturity date		June 9, 2019		June 9, 2021		June 9, 2019
	Interest rate base		LIBOR		LIBOR		LIBOR
	LIBOR floor		—%		0.75%		—%
	Interest rate minimum margin (1)		1.50%		3.00%		1.50%
	Interest rate maximum margin (1)		2.25%		3.00%		2.25%
	Minimum principal payment - amount (2)		$5,625		$1,000		$—
	Minimum principal payment - frequency		Quarterly		Quarterly		Once
	Minimum principal payment - commencement date (2)		31-Mar-15		30-Jun-14		30-Jun-19
	____________
	-1	Interest rate margins on the Term Loan A and Revolver are based on the Company's consolidated leverage ratio. Additionally, after December 31, 2014, interest rate margins on the Term Loan B will be determined by the Company's consolidated leverage ratio, and will range from 2.75% to 3.00%. As of December 31, 2014, interest accrues at 2.16% and 3.75% on the Term Loan A and Term Loan B, respectively.
	The commitment fee for the unused portion of the Revolver is also based on the Company's consolidated leverage ratio, and ranges from 0.25% to 0.35%. As of December 31, 2014, commitment fees on the unused portion of the Revolver accrue at 0.30% and letter of credit fees accrue at 2.00%.
	-2	Commencing in March 2017, the minimum principal payment amount on the Term Loan A is $11.3 million.
	2013 Agreement		Term Loan B-1		Term Loan B-2		Revolver
	Maximum borrowing capacity		$350,000		$410,000		$400,000
	Final maturity date		21-Dec-16		21-Dec-17		21-Sep-16
	Interest rate base		LIBOR		LIBOR		LIBOR
	LIBOR floor		—%		1.00%		—%
	Interest rate minimum margin (1)		2.75%		3.00%		3.00%
	Interest rate maximum margin (1)		2.75%		3.00%		3.25%
	____________
	-1	As of December 31, 2013, interest accrued at 2.92% and 4.00% on the Company’s first lien term loan B-1 and B-2 tranches, respectively. The commitment fee for the unused portion of the $400.0 million revolving credit facility ranged from 0.25% to 0.50%, depending on the Company’s consolidated leverage ratio.
	Senior Notes
	Other than the Company’s accounts receivable securitization as discussed in Note 11 and its outstanding capital lease obligations as discussed in Note 13, the Company's long-term debt consisted of the following (in thousands):
		December 31,
		2014				2013
	2014 Agreement: Term Loan A, due June 2019	$	500,000			$	—
	2014 Agreement: Term Loan B, due June 2021, net of $920 OID as of December 31, 2014	396,080				—
	2013 Agreement: Term Loan B-1 tranche, due December 2016	—				229,000
	2013 Agreement: Term Loan B-2 tranche, due December 2017	—				410,000
	Senior Notes, due November 15, 2018, net of $6,175 OID as of December 31, 2013	—				493,825
	Other	6,980				17,480
	Long-term debt	903,060				1,150,305
	Less: current portion	(31,445		)		(11,387		)
	Noncurrent portion of long term debt	$	871,615			$	1,138,918
	Revolving line of credit (1)	$	57,000			$	17,000
	Long-term debt, including revolving line of credit	$	960,060			$	1,167,305
	____________
	-1	In addition to borrowings, the Company also had outstanding letters of credit of $100.3 million under the $450.0 million Revolver at December 31, 2014 and $108.5 million under the $400.0 million Revolver at December 31, 2013, primarily related to workers' compensation and self-insurance liabilities.

Leases_Leases_Tables

Leases Leases [Tables]	12 Months Ended
	Dec. 31, 2014
Leases [Abstract]
Leases of Lessee Disclosure [Text Block]	As of December 31, 2014, annual future minimum lease commitments for all noncancelable leases were (in thousands):
		Operating		Capital
	2015	$	210,774	$	48,518
	2016	157,050		48,863
	2017	104,741		50,544
	2018	55,674		25,812
	2019	19,634		5,400
	Thereafter	43,086		38,908
	Total minimum lease payments	$	590,959	$	218,045
	Less: amounts representing interest			(17,039		)
	Present value of minimum lease payments			201,006
	Less: current portion			(42,902		)
	Capital lease obligations, long-term			$	158,104
Operating Leases of Lessor Disclosure [Text Block]	The Company’s wholly-owned financing subsidiaries lease revenue equipment to the Company’s owner-operators under operating leases. Annual future minimum lease payments receivable under operating leases for the periods noted below were (in thousands):
	2015	$	132,007
	2016	93,370
	2017	60,269
	2018	18,844
	2019	—
	Thereafter	—
	Total	$	304,490

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]	Losses on cash flow hedging, reclassified out of AOCI were as follows (in thousands):
			Year Ended December 31,
		Reclassified to:	2014				2013				2012
	Interest rate swaps	Derivative interest expense	$	6,218			$	3,143			$	5,101
	Income tax (benefit) expense	Income tax expense	(2,220		)		(1,226		)		1,989
		Net income	$	3,998			$	1,917			$	7,090
Classification Of Gains And Losses On Interest Rate Derivative Contracts Designated As Hedging Instruments	The following table presents pre-tax gains (losses) from changes in fair value, included in AOCI and earnings (in thousands):
		2014				2013				2012
	Losses recognized in AOCI from cash flow hedges (effective portion)	$	—			$	145			$	2,786
	Loss reclassified from AOCI into income from cash flow hedges (effective portion)	$	6,218			$	3,143			$	5,101
	Loss recognized in income from de-designated derivative contracts	277				709				—
	Derivative interest expense	$	6,495			$	3,852			$	5,101

Equity_and_Stockbased_Compensa1

Equity and Stock-based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Compensation Expense Related To Stock-Based Compensation	tock-based compensation expense, which is included in "Salaries, wages and employee benefits" in the consolidated income statements is comprised of the following (in thousands):
		Year Ended December 31,
		2014				2013			2012
	Stock options	$	3,007			$	3,359		$	4,886
	Restricted stock shares and RSUs	1,600				887			4
	Performance shares	789				399			—
	Total stock-based compensation expense	$	5,396			$	4,645		$	4,890
	Income tax benefit	$	1,926			$	1,788		$	1,883
Schedule of Unrecognized Compensation Cost, Nonvested Awards [Table Text Block]	The following table presents the total unrecognized stock-based compensation expense and the expected weighted average period over which these expenses will be recognized:
		December 31, 2014
		Expense				Weighted Average Period
		(In thousands)				(In years)
	Stock options	$	1,506			1.27
	Restricted stock shares and RSUs	$	5,234			1.38
	Performance shares	$	1,565			1.15
Summary Of Activity Related To Stock Options	A summary of the activity related to stock options for the year ended December 31, 2014 was as follows:
		Shares Under			Weighted Average			Weighted Average Remaining Contractual Term		Aggregate
		Option			Exercise Price					Intrinsic
										Value (1)
								(In years)		(In thousands)
	Outstanding at January 1, 2014	4,785,133			$	10.7		5.28		$	55,059
	Granted	175,142			23.3
	Exercised	(1,100,998	)		10.43
	Expired	(7,624	)		10.14
	Forfeited	(86,779	)		12.47
	Outstanding at December 31, 2014	3,764,874			$	11.34		4.68		$	65,089
	Aggregate number of stock options expected to vest at a future date as of December 31, 2014	1,485,666			$	10.87		6.27		$	16,846
	Exercisable at December 31, 2014	2,776,536			$	10.63		6.13		$	49,973
Weighted Average Assumptions	The fair value of each stock option grant is estimated on the grant date using the Black-Scholes-Merton option-pricing model, which uses a number of assumptions to determine the fair value of the options on the grant date. The following table presents the weighted average assumptions used to determine the fair value of stock options issued:
		2014		2013		2012
	Dividend yield	—%		—%		—%
	Risk-free rate of return	1.28%		1.04%		1.20%
	Expected volatility	40.00%		40.80%		41.40%
	Expected term (in years)	5.8		5.8		6.3
	Weighted average fair value of stock options granted	$6.79		$5.90		$3.56
Summary Of Exercise Of Stock Options	The following table summarizes stock option exercise information for the years presented (in thousands, except share data):
		2014				2013			2012
	Number of stock options exercised	1,100,998				1,210,184			24,427
	Intrinsic value of stock options exercised	$	15,830			$	8,773		$	25
	Cash received upon exercise of stock options	$	11,488			$	12,985		$	268
	Income tax benefit (deficiency)	$	3,730			$	187		$	(370	)
Status Of Nonvested Shares	The following table is a rollforward of nonvested restricted stock awards:
		Restricted Stock Awards
		Number of Awards			Weighted Average Fair Value
	Nonvested at January 1, 2014	272,156			$	16.2
	Granted	221,070			23.24
	Vested	(98,866	)		16.12
	Forfeited	(20,051	)		19.87
	Nonvested at December 31, 2014	374,309			$	19.95

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Tax Expense (Benefit)	Income tax expense (benefit) was (in thousands):
		2014			2013			2012
	Current expense (benefit):
	Federal	$	81,117		$	(224	)	$	9,913
	State	8,861			5,143			3,148
	Foreign	4,107			1,530			1,949
		94,085			6,449			15,010
	Deferred expense (benefit):
	Federal	(4,189		)	85,512			47,501
	State	1,975			4,273			(2,010		)
	Foreign	(2,397		)	4,748			1,113
		$	(4,611	)	94,533			46,604
	Income tax expense	$	89,474		$	100,982		$	61,614
Schedule Of Effective Income Tax Rate Reconciliation	The Company’s effective tax rate was 35.7%, 39.4% and 30.5%, for the years ended December 31, 2014, 2013 and 2012, respectively. Expected tax expense is computed by applying the United States federal corporate income tax rate of 35.0% to earnings before income taxes. Actual tax expense differs from expected tax expense as follows (in thousands):
		2014			2013			2012
	Computed “expected” tax expense	$	87,719		$	89,742		$	70,595
	Increase (decrease) in income taxes resulting from:
	State income taxes, net of federal income tax benefit	6,866			6,912			6,627
	Central pre-affiliation earnings taxed as S-Corp	—			(4,986		)	(9,118		)
	State tax rate change in deferred items	40			711			(6,414		)
	Foreign tax rate change in deferred items	—			5,023			—
	Effect of providing taxes on mark-to-market adjustment of derivatives recorded in AOCI	—			—			1,785
	Other	(5,151		)	3,580			(1,861		)
	Income tax expense	$	89,474		$	100,982		$	61,614
Components Of Net Deferred Tax Asset (Liability)	The components of the net deferred tax asset (liability) were (in thousands):
		December 31,
		2014			2013
	Deferred tax assets:
	Self-insurance accruals	$	61,305		$	49,810
	Allowance for doubtful accounts	9,561			6,968
	Derivative financial instruments	2,350			4,537
	Vacation accrual	4,342			3,899
	Minimum tax credit	—			5,061
	Net operating loss	2,507			4,529
	Amortization of stock options	9,598			10,782
	Other	16,040			17,259
	Total deferred tax assets	105,703			102,845
	Valuation allowance	—			—
	Total deferred tax assets, net	105,703			102,845
	Deferred tax liabilities:
	Property and equipment, principally due to differences in depreciation	(401,963		)	(393,239		)
	Prepaid taxes, licenses and permits deducted for tax purposes	(13,170		)	(12,897		)
	Cancellation of debt	(7,503		)	(9,401		)
	Intangible assets	(115,115		)	(119,567		)
	Other	(5,345		)	(7,354		)
	Total deferred tax liabilities	(543,096		)	(542,458		)
	Net deferred tax liability	$	(437,393	)	$	(439,613	)
Current Deferred Tax Liability Included In Accrued Liabilities	These amounts are presented in the consolidated balance sheets in the indicated captions, except the current deferred tax liability which is included in accrued liabilities (in thousands):
		December 31,
		2014			2013
	Current deferred tax asset	$	44,861		$	46,833
	Current deferred tax liability	(1,614		)	(2,246		)
	Noncurrent deferred tax liability	(480,640		)	(484,200		)
	Net deferred tax liability	$	(437,393	)	$	(439,613	)
Reconciliation Of Unrecognized Tax Benefits	The following is a rollforward of our unrecognized tax benefits (in thousands):
		2014			2013			2012
	Unrecognized tax benefits at beginning of year	$	2,385		$	2,385		$	2,332
	Increases for tax positions taken prior to beginning of year	95			—			149
	Decreases for tax positions taken prior to beginning of year	(741		)	—			(53		)
	Settlements	—			—			(43		)
	Unrecognized tax benefits at end of year	$	1,739		$	2,385		$	2,385

Related_Party_Transactions_Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Schedule Of Services Received And Provided By Company	The Company provided and received freight services, facility leases, equipment leases, and other services, including repair, equipment sales and employee services to and from several companies controlled by and/or affiliated with the Company's Chief Executive Officer and majority shareholder, Jerry Moyes, as follows (in thousands):
		2014
		Central		Other		Total
		Freight Lines,		Affiliated
		Inc.		Entities
	Services Provided by Swift:
	Freight Services (1)	$	25	$	199	$	224
	Facility Leases	$	843	$	20	$	863
	Other Services (4)	$	388	$	4	$	392
	Services Received by Swift:
	Freight Services (2)	$	24	$	—	$	24
	Facility Leases	$	400	$	228	$	628
	Other Services (3)	$	—	$	772	$	772
		2013
		Central		Other		Total
		Freight Lines,		Affiliated
		Inc.		Entities
	Services Provided by Swift:
	Freight Services (1)	$	15	$	160	$	175
	Facility Leases	$	716	$	20	$	736
	Other Services (4)	$	1,000	$	159	$	1,159
	Services Received by Swift:
	Freight Services (2)	$	47	$	—	$	47
	Facility Leases	$	399	$	200	$	599
	Other Services (3)	$	—	$	1,008	$	1,008
		2012
		Central		Other		Total
		Freight Lines,		Affiliated
		Inc.		Entities
	Services Provided by Swift:
	Freight Services (1)	$	8,117	$	1,265	$	9,382
	Facility Leases	$	711	$	20	$	731
	Other Services (4)	$	—	$	135	$	135
	Services Received by Swift:
	Freight Services (2)	$	50	$	—	$	50
	Facility Leases	$	626	$	—	$	626
	Other Services (3)	$	—	$	1,246	$	1,246
	____________
	-1	The rates the Company charges for freight services to each of these companies for transportation services are market rates, which are comparable to what it charges third-party customers. These transportation services provided to affiliated entities provide the Company with an additional source of operating revenue at its normal freight rates.
	-2	Transportation services received from Central Freight represent LTL (less-than-truckload) freight services rendered to haul parts and equipment to Company shop locations. The rates paid to Central Freight for these loads are comparable to market rates charged by other non-affiliated LTL carriers.
	-3	Other services received by the Company from the identified related parties included executive air transport, fuel storage, event fees, equipment purchases, miscellaneous repair services, and certain third-party payroll and employee benefits administration services.
	-4	Other services provided by the Company to the identified related parties included: equipment sales and miscellaneous services.
	Receivables and Payables pertaining to these related party transactions were (in thousands):
		Central		Other		Total
		Freight Lines,		Affiliated
		Inc.		Entities
	December 31, 2014:
	Receivable	$	93	$	23	$	116
	Payable	$	1	$	—	$	1
	December 31, 2013:
	Receivable	$	1,034	$	32	$	1,066
	Payable	$	74	$	1	$	75
Related Party Transactions Disclosure [Text Block]	Related Party Transactions
	The Company provided and received freight services, facility leases, equipment leases, and other services, including repair, equipment sales and employee services to and from several companies controlled by and/or affiliated with the Company's Chief Executive Officer and majority shareholder, Jerry Moyes, as follows (in thousands):
		2014
		Central		Other		Total
		Freight Lines,		Affiliated
		Inc.		Entities
	Services Provided by Swift:
	Freight Services (1)	$	25	$	199	$	224
	Facility Leases	$	843	$	20	$	863
	Other Services (4)	$	388	$	4	$	392
	Services Received by Swift:
	Freight Services (2)	$	24	$	—	$	24
	Facility Leases	$	400	$	228	$	628
	Other Services (3)	$	—	$	772	$	772
		2013
		Central		Other		Total
		Freight Lines,		Affiliated
		Inc.		Entities
	Services Provided by Swift:
	Freight Services (1)	$	15	$	160	$	175
	Facility Leases	$	716	$	20	$	736
	Other Services (4)	$	1,000	$	159	$	1,159
	Services Received by Swift:
	Freight Services (2)	$	47	$	—	$	47
	Facility Leases	$	399	$	200	$	599
	Other Services (3)	$	—	$	1,008	$	1,008
		2012
		Central		Other		Total
		Freight Lines,		Affiliated
		Inc.		Entities
	Services Provided by Swift:
	Freight Services (1)	$	8,117	$	1,265	$	9,382
	Facility Leases	$	711	$	20	$	731
	Other Services (4)	$	—	$	135	$	135
	Services Received by Swift:
	Freight Services (2)	$	50	$	—	$	50
	Facility Leases	$	626	$	—	$	626
	Other Services (3)	$	—	$	1,246	$	1,246
	____________
	-1	The rates the Company charges for freight services to each of these companies for transportation services are market rates, which are comparable to what it charges third-party customers. These transportation services provided to affiliated entities provide the Company with an additional source of operating revenue at its normal freight rates.
	-2	Transportation services received from Central Freight represent LTL (less-than-truckload) freight services rendered to haul parts and equipment to Company shop locations. The rates paid to Central Freight for these loads are comparable to market rates charged by other non-affiliated LTL carriers.
	-3	Other services received by the Company from the identified related parties included executive air transport, fuel storage, event fees, equipment purchases, miscellaneous repair services, and certain third-party payroll and employee benefits administration services.
	-4	Other services provided by the Company to the identified related parties included: equipment sales and miscellaneous services.
	Receivables and Payables pertaining to these related party transactions were (in thousands):
		Central		Other		Total
		Freight Lines,		Affiliated
		Inc.		Entities
	December 31, 2014:
	Receivable	$	93	$	23	$	116
	Payable	$	1	$	—	$	1
	December 31, 2013:
	Receivable	$	1,034	$	32	$	1,066
	Payable	$	74	$	1	$	75
	In addition to the transactions identified above,the Company purchased parts and equipment totaling $184 thousand from Thermo King West, Inc. and Thermo King Chesapeake, Inc.; companies owned by board of directors member William Riley III, after his addition to the board in July 2014. As of December 31, 2014, the Company had total payables of approximately $23 thousand due to Thermo King West, Inc. and Thermo King Chesapeake, Inc.

Fair_Value_Measurement_Tables

Fair Value Measurement (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Carrying Amounts And Estimated Fair Values Of Financial Instruments	The following table presents the carrying amounts and estimated fair values of the Company’s financial instruments (in thousands):
			December 31,
			2014						2013
			Carrying			Estimated			Carrying			Estimated
			Value			Fair Value			Value			Fair Value
	Financial Assets:
	Restricted investments		$	24,510		$	24,502		$	25,814		$	25,808
	Financial Liabilities:
	2014 Agreement: Term Loan A		500,000			500,000			—			—
	2014 Agreement: Term Loan B		396,080			390,436			—			—
	2013 Agreement: Term Loan B-1		—			—			229,000			230,031
	2013 Agreement: Term Loan B-2		—			—			410,000			412,358
	Senior Notes		—			—			493,825			549,059
	Securitization of accounts receivable		334,000			334,000			264,000			264,000
	The carrying
Liabilities That Were Measured At Estimated Fair Value On Recurring Basis	As of December 31, 2014 and 2013, no assets of the Company were measured at estimated fair value on a recurring basis. As of December 31, 2014 and 2013, information about inputs into the estimated fair value measurements of each major category of the Company’s liabilities that were measured at estimated fair value on a recurring basis in periods subsequent to their initial recognition was as follows (in thousands):
					Fair Value Measurements at Reporting Date Using
		Estimated			Level 1 Inputs			Level 2 Inputs			Level 3 Inputs
		Fair Value
	As of December 31, 2014
	Interest rate swaps	$	6,109		$	—		$	6,109		$	—
	As of December 31, 2013
	Interest rate swaps	$	11,768		$	—		$	11,768		$	—
Assets That Were Measured At Estimated Fair Value On Non-Recurring Basis	As of December 31, 2013, none of the Company's assets were measured at estimated fair value on a nonrecurring basis. The following table presents assets measured at estimated fair value on a nonrecurring basis, as of December 31, 2014 (in thousands):
					Fair Value Measurements at Reporting Date Using
		Estimated Fair Value			Level 1 Inputs			Level 2 Inputs			Level 3 Inputs			Total Gains (Losses)
	As of December 31, 2014
	Other assets (1)	$	—		$	—		$	—		$	—		$	(2,308	)

Intangible_Assets_Tables

Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule Of Intangible Assets	Intangible asset balances were as follows (in thousands):
		December 31,
		2014			2013
	Customer Relationship:
	Gross carrying value	$	275,324		$	275,324
	Accumulated amortization	(156,428		)	(139,614		)
	Trade Name:
	Gross carrying value	181,037			181,037
	Intangible assets, net	$	299,933		$	316,747

Goodwill_Tables

Goodwill (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following presents the components of goodwill by reportable segment as of December 31, 2014 and 2013 (in thousands):
		Gross Carrying Amount		Accumulated Impairment Losses			Net Carrying Amount
	Truckload	$	376,998	$	(190,394	)	$	186,604
	Dedicated	130,742		(64,090		)	66,652
	Total	$	507,740	$	(254,484	)	$	253,256

Earnings_Loss_Per_Share_Tables

Earnings (Loss) Per Share (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Calculation Of Basic And Diluted Earnings Per Share Attributable To Stockholders	Earnings per Share
	Basic and diluted earnings per share, as presented in the consolidated income statements, are calculated by dividing net income by the respective weighted average common shares outstanding during the period.
	The following table reconciles basic weighted average shares outstanding to diluted weighted average shares outstanding (in thousands):
		2014	2013	2012
	Basic weighted average common shares outstanding	141,431	140,179	139,532
	Dilutive effect of stock options	2,044	2,042	87
	Diluted weighted average common shares outstanding	143,475	142,221	139,619
	Anti-dilutive shares excluded from diluted earnings per share (1)	162	174	4,356
	____________
	-1	The impact of certain outstanding options to purchase shares of the Company’s Class A common stock were anti-dilutive because the options' exercise prices were greater than the average market prices of the common shares. These anti-dilutive shares were excluded from the calculation of diluted earnings per share.

Quarterly_Result_Of_Operations1

Quarterly Result Of Operations (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Selected Quarterly Financial Information [Abstract]
Quarterly Results of Operations
		First Quarter		Second Quarter		Third Quarter		Fourth Quarter
		(In thousands, except per share data)
	2014:00:00
	Operating revenue	$	1,008,446	$	1,075,898	$	1,074,880	$	1,139,500
	Operating income	46,170		94,022		97,411		132,467
	Net income	12,305		40,198		50,158		58,491
	Basic earnings per share	0.09		0.28		0.35		0.41
	Diluted earnings per share	0.09		0.28		0.35		0.41
	2013:00:00
	Operating revenue (1)	$	981,608	$	1,029,071	$	1,032,127	$	1,075,389
	Operating income (1)	69,718		100,266		84,420		102,555
	Net income (1)	30,292		49,879		29,953		45,298
	Basic earnings per share (1)	0.22		0.36		0.21		0.32
	Diluted earnings per share (1)	0.21		0.35		0.21		0.32

Segment_Information_Tables

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Summary Of Financial Information By Segments	Set forth in the tables below is certain financial information with respect to the Company’s segments (in thousands):
		Operating Revenue
		2014			2013			2012
	Truckload	$	2,301,010		$	2,313,035		$	2,282,342
	Dedicated	892,078			738,929			724,405
	Central Refrigerated	417,980			452,531			415,733
	Intermodal	401,577			376,075			355,494
	Subtotal	4,012,645			3,880,570			3,777,974
	Non-reportable segment	342,969			287,853			268,821
	Intersegment eliminations	(56,890		)	(50,228		)	(70,710		)
	Consolidated operating revenue	$	4,298,724		$	4,118,195		$	3,976,085
		Operating Income (Loss)
		2014			2013			2012
	Truckload	$	258,072		$	225,963		$	246,005
	Dedicated	75,794			83,520			74,026
	Central Refrigerated	14,035			17,682			21,334
	Intermodal	8,298			5,619			(6,486		)
	Subtotal	356,199			332,784			334,879
	Non-reportable segment	13,871			24,175			16,937
	Consolidated operating income	$	370,070		$	356,959		$	351,816
		Depreciation and Amortization Expense
		2014			2013			2012
	Truckload	$	113,875		$	127,404		$	121,004
	Dedicated	53,682			45,568			44,088
	Central Refrigerated	12,510			13,926			14,539
	Intermodal	10,875			9,268			9,209
	Subtotal	190,942			196,166			188,840
	Non-reportable segment	30,180			29,842			29,999
	Consolidated depreciation and amortization expense	$	221,122		$	226,008		$	218,839

Description_of_Business_and_Ba3

Description of Business and Basis of Presentation Central Acquisition (Details) (USD $)	0 Months Ended	3 Months Ended										12 Months Ended			0 Months Ended
	Aug. 06, 2013	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2011
Business Acquisition [Line Items]
Accounts Receivable Proceeds Used For Acquisition	$100,000,000
Assets, Current		800,408,000				734,032,000						800,408,000	734,032,000	742,091,000	734,032,000
Assets		2,937,582,000				2,809,008,000						2,937,582,000	2,809,008,000	2,791,981,000	2,809,008,000
Liabilities, Current		422,222,000				384,368,000						422,222,000	384,368,000	383,449,000	384,368,000
Liabilities		2,467,288,000				2,525,421,000						2,467,288,000	2,525,421,000	2,501,777,000	2,525,421,000
Total stockholders’ equity		470,294,000				283,587,000						470,294,000	283,587,000	290,204,000	283,587,000	155,186,000
Revenues		1,139,500,000	1,074,880,000	1,075,898,000	1,008,446,000	1,075,389,000	1,032,127,000	1,029,071,000	[1]	981,608,000	[1]	4,298,724,000	4,118,195,000	3,976,085,000
Operating income		132,467,000	97,411,000	94,022,000	46,170,000	102,555,000	84,420,000	100,266,000	[1]	69,718,000	[1]	370,070,000	356,959,000	351,816,000
Net income		58,491,000	50,158,000	40,198,000	12,305,000	45,298,000	29,953,000	49,879,000	[1]	30,292,000	[1]	161,152,000	155,422,000	140,087,000
Basic earnings per share		$0.41	$0.35	$0.28	$0.09							$1.14	$1.11	$1
Diluted earnings per share		$0.41	$0.35	$0.28	$0.09	$0.32	$0.21	$0.35	[1]	$0.21	[1]	$1.12	$1.09	$1
Net Cash Provided by (Used in) Operating Activities												395,781,000	473,504,000	447,118,000
Net Cash Provided by (Used in) Investing Activities												-139,750,000	-311,720,000	-169,129,000
Net Cash Provided by (Used in) Financing Activities												-210,077,000	-156,202,000	-306,477,000
Central Refrigerated Service, Inc. [Member]
Business Acquisition [Line Items]
Accounts Receivable Proceeds Used For Acquisition	100,000,000
Business Combination, Consideration Transferred, Liabilities Incurred	36,000,000
Business Combination, Consideration Transferred	225,000,000
Payments to Acquire Businesses, Gross	189,000,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Consideration Transferred															2,400,000
Central Refrigerated Service, Inc. [Member]
Business Acquisition [Line Items]
Assets, Current														68,211,000
Assets														160,560,000
Liabilities, Current														60,813,000
Liabilities														100,367,000
Total stockholders’ equity														60,193,000
Revenues														484,657,000
Operating income														29,770,000
Net income														25,498,000
Basic earnings per share														$0.18
Diluted earnings per share														$0.18
Net Cash Provided by (Used in) Operating Activities														40,562,000
Net Cash Provided by (Used in) Investing Activities														3,370,000
Net Cash Provided by (Used in) Financing Activities														-43,932,000
Consolidation, Eliminations [Member]
Business Acquisition [Line Items]
Assets, Current														-657,000
Assets														-757,000
Liabilities, Current														-657,000
Liabilities														-657,000
Total stockholders’ equity														-100,000
Revenues														-1,754,000
Operating income														0
Net income														0
Basic earnings per share														$0
Diluted earnings per share														$0
Net Cash Provided by (Used in) Operating Activities														0
Net Cash Provided by (Used in) Investing Activities														0
Net Cash Provided by (Used in) Financing Activities														0
Scenario, Previously Reported [Member]
Business Acquisition [Line Items]
Assets, Current														674,537,000
Assets														2,632,178,000
Liabilities, Current														323,293,000
Liabilities														2,402,067,000
Total stockholders’ equity														230,111,000
Revenues														3,493,182,000
Operating income														322,046,000
Net income														114,589,000
Basic earnings per share														$0.82
Diluted earnings per share														$0.82
Net Cash Provided by (Used in) Operating Activities														406,556,000
Net Cash Provided by (Used in) Investing Activities														-172,499,000
Net Cash Provided by (Used in) Financing Activities														($262,545,000)
Chief Executive Officer [Member] | Central Refrigerated Service, Inc. [Member] | Class B Common Stock [Member]
Business Acquisition [Line Items]
Business Combinations, Equity Interests Issued and Issuable, Held In Escrow	1,131,862
[1]	The first and second quarter results of 2013 have been recast due to the acquisition of Central. Refer to Note1 for further information regarding the acquisition.

Description_of_Business_and_Ba4

Description of Business and Basis of Presentation Description of Business (Details)	12 Months Ended
	Dec. 31, 2014
	Segment
	Trailer
	Vehicle
Description of Business [Abstract]
Number of Reportable Segments	4
Number Of Company Operated National Terminal Network And Tractor Fleet	18,836
Number Of Tractors Driven By Company Drivers	13,882
Number Of Owner Operator Tractors	4,954
Number Of Fleet Of Trailers	61,652
Number Of Intermodal Containers	9,150

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2014
Percentage Of Income Tax Positions Likely To Be Realized	50.00%
Percentage Of Amortizable Goodwill And Intangible Asset	150.00%
Minimum [Member] | Land, Buildings and Improvements [Member]
Property, Plant and Equipment, Useful Life	5 years
Minimum [Member] | Revenue And Service Equipment [Member]
Property, Plant and Equipment, Useful Life	3 years
Minimum [Member] | Furniture and Fixtures [Member]
Property, Plant and Equipment, Useful Life	3 years
Maximum [Member] | Land, Buildings and Improvements [Member]
Property, Plant and Equipment, Useful Life	40 years
Maximum [Member] | Revenue And Service Equipment [Member]
Property, Plant and Equipment, Useful Life	20 years
Maximum [Member] | Furniture and Fixtures [Member]
Property, Plant and Equipment, Useful Life	5 years
Customer Relationships [Member]
Finite-Lived Intangible Asset, Useful Life	15 years

Restricted_Investments_Amortiz

Restricted Investments (Amortized Cost, Gross Unrealized Gains And Losses, Estimated Fair Value Of Fixed Maturity Securities) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Schedule of Held-to-maturity Securities [Line Items]
Restricted held to maturity investments	1 year
Securities with unrealized losses for less than 12 months	24	15
U.S. Corporate Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Cost or Amortized Cost	20,892	20,197
Gross Unrealized, Gains	2	2
Gross Unrealized, Temporary Losses	-10	-7
Estimated Fair Value	20,884	20,192
Foreign Corporate Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Cost or Amortized Cost	1,503	3,502
Gross Unrealized, Gains	0	0
Gross Unrealized, Temporary Losses	0	0
Estimated Fair Value	1,503	3,502
Negotiable Certificate Of Deposits [Member]
Schedule of Held-to-maturity Securities [Line Items]
Cost or Amortized Cost	2,115	2,115
Gross Unrealized, Gains	0	0
Gross Unrealized, Temporary Losses	0	-1
Estimated Fair Value	2,115	2,114
Total Restricted Investments [Member]
Schedule of Held-to-maturity Securities [Line Items]
Cost or Amortized Cost	24,510	25,814
Gross Unrealized, Gains	2	2
Gross Unrealized, Temporary Losses	-10	-8
Estimated Fair Value	24,502	25,808

Accounts_Receivable_Accounts_R

Accounts Receivable Accounts Receivable (Schedule Of Accounts Receivable) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Valuation and Qualifying Accounts Disclosure [Line Items]
Accounts receivable, gross	$488,923	$425,940
Less: Allowance for doubtful accounts	-9,924	-7,504	-7,432	-6,617
Accounts receivable, net	478,999	418,436
Trade Customers [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Accounts receivable, gross	457,823	392,233
Equipment Manufacturers [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Accounts receivable, gross	7,725	6,102
Other [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Accounts receivable, gross	$23,375	$27,605

Accounts_Receivable_Accounts_R1

Accounts Receivable Accounts Receivable (Schedule Of Allowance For Doubtful Accounts) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Receivables [Abstract]
Beginning balance	$7,504	$7,432	$6,617
Provision	2,844	1,370	977
Recoveries	89	35	103
Write-offs	-513	-1,333	-265
Ending balance	$9,924	$7,504	$7,432

Assets_Held_For_Sale_Schedule_

Assets Held For Sale (Schedule Of Assets Held For Sale) (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Long Lived Assets Held-for-sale [Line Items]
Assets held for sale	$2,907	$19,268
Land And Facilities [Member]
Long Lived Assets Held-for-sale [Line Items]
Assets held for sale	288	14,627
Revenue Equipment [Member]
Long Lived Assets Held-for-sale [Line Items]
Assets held for sale	$2,619	$4,641

Assets_Held_For_Sale_Narrative

Assets Held For Sale (Narrative) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	property
Property, Plant and Equipment Assets Held-for-sale Disclosure [Abstract]
Period of time assets are expected to be sold, months	12 months
Number of properties sold	5
Statement [Line Items]
Asset held for sale	$14,500,000
Gain (Loss) on Sale of Properties	3,018,000	6,876,000	0
Gain on sale of real property	0	6,876,000	0
Utah, Oregon, California and Georgia [Member]
Statement [Line Items]
Asset held for sale	14,100,000
Arizona [Member]
Statement [Line Items]
Asset held for sale		$25,600,000

Equity_Investment_And_Note_Rec1

Equity Investment And Note Receivable- Swift Power Services, LLC (Detail) (USD $)	3 Months Ended	12 Months Ended			1 Months Ended
	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Feb. 29, 2012
					business
Schedule of Equity Method Investments [Line Items]
Impairments on non-operating assets	$6,000,000	$0	$0	$5,979,000
Equity losses of investee		0	537,000	1,007,000
Carrying value of note receivable, net	15,625,000	15,575,000	15,625,000
SPS Equity Investee [Member]
Schedule of Equity Method Investments [Line Items]
Company contribution in Swift Power Services, LLC	0	0	0
Equity losses of investee		0	277,000	1,000,000
Carrying value of note receivable, net		0
Swift Power Services, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company contribution in Swift Power Services, LLC					500,000
Ownership interest in Swift Power Services, LLC					49.95%
Number of trucking companies to be acquired					3
Secured promissory note loaned to SPS					$7,500,000

Accrued_Liabilities_Details

Accrued Liabilities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accrued Liabilities [Abstract]
Employee compensation	$50,398	$56,427
Owner-operator lease purchase reserve	10,418	10,335
Income tax accrual	3,541	4,785
Accrued owner-operator expenses	6,507	6,866
Deferred revenue	1,504	484
Fuel and property taxes	3,812	5,241
Accrued interest expense	4,216	11,328
Other	19,933	15,279
Accrued liabilities	$100,329	$110,745

Notes_Receivable_Details

Notes Receivable (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Receivables [Abstract]
Notes receivable due from owner-operators, with interest rates at 15%, secured by revenue equipment. Terms range from several months to three years	$13,642	$13,264
Other	1,933	2,361
Total notes receivable	15,575	15,625
Less: current portion	-9,202	-7,210
Long-term notes receivable	$6,373	$8,415

Claims_Accruals_Details

Claims Accruals (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Claims Accruals [Line Items]
Claims accrual	$224,944	$194,051
Less: current portion	-81,251	-75,469
Long-term claim accruals	143,693	118,582
Auto And Collision Liability [Member]
Claims Accruals [Line Items]
Claims accrual	112,548	102,462
Workers Compensation Liability [Member]
Claims Accruals [Line Items]
Claims accrual	82,439	70,145
Owner Operator Claims Liability [Member]
Claims Accruals [Line Items]
Claims accrual	13,233	8,610
Group Medical Liability [Member]
Claims Accruals [Line Items]
Claims accrual	12,064	9,946
Cargo Damage Liability [Member]
Claims Accruals [Line Items]
Claims accrual	$4,660	$2,888

Accounts_Receivable_Securitiza2

Accounts Receivable Securitization (Detail) (USD $)	0 Months Ended	12 Months Ended
	Aug. 06, 2013	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012	Sep. 26, 2014
Accounts Receivable Securitization Terms [Line Items]
Accounts Receivable Proceeds Used For Acquisition	$100,000,000
Transfers Accounted for as Secured Borrowings, Associated Liabilities, Carrying Amount		334,000,000		264,000,000
Debt Instrument, Fee		3.5		3.1	3.3
2013 RSA [Member]
Accounts Receivable Securitization Terms [Line Items]
Accounts Receivable Securitization Borrowing Base		360,700,000		300,800,000
Transfers Accounted for as Secured Borrowings, Associated Liabilities, Carrying Amount		-334,000,000		-264,000,000
Receivables Sale Agreement Borrowing Capacity		375,000,000	[1]			325,000,000
Debt Instrument, Interest Rate		0.80%
Debt Instrument, Interest Rate During Period				1.10%
Receivables Sale Agreement Termination Date		13-Jul-16
Debt Instrument, Fee		35 basis points
Interest rate base				commercial paper rates + 95 basis points
Debt Instrument, Basis Spread on Variable Rate		0.95%
Debt Instrument, Interest Rate, Unused Capacity Fee		0.35%
Accounts Receivable Securitization Remaining Borrowing		26,700,000		36,800,000
2011 RSA [Member]
Accounts Receivable Securitization Terms [Line Items]
Receivables Sale Agreement Borrowing Capacity				$275,000,000
Receivables Sale Agreement Termination Date		8-Jun-14
Debt Instrument, Fee				40 basis points
Interest rate base				commercial paper rates + 125 basis points
Debt Instrument, Basis Spread on Variable Rate				1.25%
Debt Instrument, Interest Rate, Unused Capacity Fee				0.40%
[1]	(1) On September 26, 2014, the Company exercised an accordion option, increasing borrowing capacity on the 2013 RSA from $325.0 million to $375.0 million.

Debt_And_Financing_Transaction2

Debt And Financing Transactions (Schedule Of Long-Term Debt Outstanding) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Jun. 09, 2014
Debt Instrument [Line Items]
Long Term debt, Including Revolving Line of Credit	$960,060	$1,167,305
Total	903,060	1,150,305
Other Long-term Debt	6,980	17,480
Less: current portion	-31,445	-11,387
Long-term debt and obligations under capital leases	871,615	1,138,918
2014 Agreement, Term Loan A [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	9-Jun-19
Total	500,000	0
2014 Agreement, Term Loan B [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	9-Jun-21
Original Issue Discount On Debt	920
Total	396,080	0
First Lien Term Loan B 1 [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date		21-Dec-16
Total	0	229,000	229,000
First Lien Term Loan B 2 [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date		21-Dec-17
Total	0	410,000	371,000
Senior Second Priority Secured Notes Due November 15, 2018 [Member]
Debt Instrument [Line Items]
Total	0	493,825
Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date		15-Nov-18
Original Issue Discount On Debt		$6,175

Debt_And_Financing_Transaction3

Debt And Financing Transactions (Narrative) (Detail) (USD $)

0 Months Ended

12 Months Ended

0 Months Ended

3 Months Ended

26 Months Ended

9 Months Ended

0 Months Ended

12 Months Ended

Nov. 15, 2014

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Mar. 08, 2013

Sep. 30, 2014

Jun. 30, 2014

Jun. 09, 2019

Sep. 30, 2014

Aug. 06, 2013

Dec. 31, 2015

Jun. 09, 2014

Debt Instrument [Line Items]

Debt Instrument, Fee

3.5

3.1

3.3

Debt Instrument, Repurchase Amount

$428,100,000

Letters of credit amount outstanding

100,300,000

Debt Instrument, Redemption Price, Percentage

105.00%

Debt assumed in acquisition

903,060,000

1,150,305,000

Deferred loan costs

10,400,000

8,900,000

Non-cash loss on debt extinguishment and write-offs of deferred financing costs and original issue discount

11,994,000

5,540,000

22,219,000

Minimum principal payment - commencement date (2)

31-Mar-15

Proceeds from long-term debt

900,000,000

26,267,000

11,304,000

Central Refrigerated Service, Inc. [Member]

Debt Instrument [Line Items]

Repayments of debt

38,000,000

Minimum [Member]

Debt Instrument [Line Items]

Outstanding letters of credit fees incurred

0.00%

Maximum [Member]

Debt Instrument [Line Items]

Outstanding letters of credit fees incurred

1.00%

First Lien Term Loan B 2 [Member]

Debt Instrument [Line Items]

Debt Instrument, Interest Rate During Period

4.00%

Revolving Credit Facility [Member]

Debt Instrument [Line Items]

Credit agreement, maximum borrowing capacity

400,000,000

Letters of credit amount outstanding

108,500,000

Debt Instrument, Maturity Date

21-Sep-16

Interest rate base

LIBOR

Interest rate minimum margin (1)

3.00%

[1]

Interest rate maximum margin (1)

3.25%

[1]

First Lien Term Loan B 2 [Member]

Debt Instrument [Line Items]

Credit agreement, maximum borrowing capacity

410,000,000

Minimum LIBOR rate

1.00%

Debt assumed in acquisition

0

410,000,000

371,000,000

Debt Instrument, Maturity Date

21-Dec-17

Interest rate base

LIBOR

Interest rate minimum margin (1)

3.00%

[1]

Interest rate maximum margin (1)

3.00%

[1]

First Lien Term Loan B 1 [Member]

Debt Instrument [Line Items]

Debt Instrument, Interest Rate During Period

2.92%

Credit agreement, maximum borrowing capacity

350,000,000

Debt assumed in acquisition

0

229,000,000

229,000,000

Debt Instrument, Maturity Date

21-Dec-16

Interest rate base

LIBOR

Interest rate minimum margin (1)

2.75%

[1]

Interest rate maximum margin (1)

2.75%

[1]

2014 Agreement, Term Loan A [Member]

Debt Instrument [Line Items]

Credit agreement, maximum borrowing capacity

500,000,000

Minimum LIBOR rate

0.00%

Quarterly principal payments

5,625,000

[2]

11,300,000

Debt assumed in acquisition

500,000,000

0

Debt Instrument, Maturity Date

9-Jun-19

Interest rate base

LIBOR

Interest rate minimum margin (1)

1.50%

[3]

Interest rate maximum margin (1)

2.25%

[3]

Debt Instrument, Interest Rate, Effective Percentage Rate Range, Minimum

2.16%

Minimum principal payment - frequency

Quarterly

Proceeds from long-term debt

450,000,000

50,000,000

Senior Second Priority Secured Notes [Member]

Debt Instrument [Line Items]

Face value of second priority senior notes

500,000,000

Debt Instrument, Repurchase Amount

71,900,000

71,900,000

Debt Instrument, Redemption Price, Percentage

105.58%

Debt Instrument, Interest Rate, Stated Percentage

10.00%

2012 Agreement [Member] | First Lien Term Loan B 1 [Member]

Debt Instrument [Line Items]

Frequency of payments

Quarterly

2012 Agreement [Member] | First Lien Term Loan B 2 [Member]

Debt Instrument [Line Items]

Frequency of payments

Quarterly

2013 Agreement [Member]

Debt Instrument [Line Items]

Non-cash loss on debt extinguishment and write-offs of deferred financing costs and original issue discount

-5,500,000

Notes payable, due March 2016 [Member] | Secured Debt [Member] | Central Refrigerated Service, Inc. [Member]

Debt Instrument [Line Items]

Repayments of debt

3,400,000

CRS 2013 Agreement [Member] | Revolving Credit Facility [Member] | Central Refrigerated Service, Inc. [Member]

Debt Instrument [Line Items]

Face value of second priority senior notes

50,000,000

CRS 2013 Agreement [Member] | Loans Payable [Member] | Central Refrigerated Service, Inc. [Member]

Debt Instrument [Line Items]

Face value of second priority senior notes

16,000,000

Balloon payment to be paid, as a percentage of principal

30.00%

Senior Notes [Member]

Debt Instrument [Line Items]

Non-cash loss on debt extinguishment and write-offs of deferred financing costs and original issue discount

-39,900,000

Debt Instrument, Maturity Date

15-Nov-18

First Lien Term Loan One [Member]

Debt Instrument [Line Items]

Non-cash loss on debt extinguishment and write-offs of deferred financing costs and original issue discount

-22,200,000

2014 Agreement, Term Loan B [Member]

Debt Instrument [Line Items]

Credit agreement, maximum borrowing capacity

400,000,000

Minimum LIBOR rate

0.75%

Quarterly principal payments

1,000,000

Debt assumed in acquisition

396,080,000

0

Debt Instrument, Maturity Date

9-Jun-21

Interest rate base

LIBOR

Interest rate minimum margin (1)

3.00%

[3]

2.75%

Interest rate maximum margin (1)

3.00%

[3]

3.00%

Debt Instrument, Interest Rate, Effective Percentage Rate Range, Maximum

3.75%

Minimum principal payment - frequency

Quarterly

Minimum principal payment - commencement date (2)

30-Jun-14

2014 Agreement, Credit Facility [Member]

Debt Instrument [Line Items]

Credit agreement, maximum borrowing capacity

450,000,000

Minimum LIBOR rate

0.00%

Quarterly principal payments

0

Outstanding letters of credit fees incurred

0.00%

Debt Instrument, Maturity Date

9-Jun-19

Interest rate base

LIBOR

Interest rate minimum margin (1)

1.50%

[3]

Interest rate maximum margin (1)

2.25%

[3]

Minimum principal payment - frequency

Once

Minimum principal payment - commencement date (2)

30-Jun-19

Proceeds from long-term debt

164,000,000

2014 Agreement, Credit Facility [Member] | Minimum [Member]

Debt Instrument [Line Items]

Outstanding letters of credit fees incurred

0.00%

2014 Agreement, Credit Facility [Member] | Maximum [Member]

Debt Instrument [Line Items]

Outstanding letters of credit fees incurred

0.00%

Letter of Credit [Member]

Debt Instrument [Line Items]

Debt Instrument, Fee

0.02

Fixed Rate Notes [Member]

Debt Instrument [Line Items]

Debt Instrument, Redemption Price, Percentage

12.50%

Central Refrigerated Service, Inc. [Member]

Debt Instrument [Line Items]

Proceeds from lines of credit

85,000,000

Central Refrigerated Service, Inc. [Member] | Notes payable, due May 2015 [Member] | Secured Debt [Member]

Debt Instrument [Line Items]

Debt assumed in acquisition

$1,200,000

$2,190,000

[1]

(1)As of December 31, 2013, interest accrued at 2.92% and 4.00% on the Company’s first lien term loan B-1 and B-2 tranches, respectively. The commitment fee for the unused portion of the $400.0 million revolving credit facility ranged from 0.25% to 0.50%, depending on the Company’s consolidated leverage ratio.

[2]

(2)Commencing in March 2017, the minimum principal payment amount on the Term Loan A is $11.3 million.

[3]

(1)Interest rate margins on the Term Loan A and Revolver are based on the Company's consolidated leverage ratio. Additionally, after December 31, 2014, interest rate margins on the Term Loan B will be determined by the Company's consolidated leverage ratio, and will range from 2.75% to 3.00%. As of December 31, 2014, interest accrues at 2.16% and 3.75% on the Term Loan A and Term Loan B, respectively.

Leases_Detail

Leases (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Leases [Abstract]
2015	$132,007,000
Operating Leases, Future Minimum Payments Due, Next Twelve Months	210,774,000,000
Capital leases obligations, current	-42,902,000	-63,669,000
Accumulated amortization	68,000,000	89,000,000
Capital Leases, Net Investment in Direct Financing Leases	270,600,000	325,200,000
Capital Leases, Future Minimum Payments Due
2014	48,518,000
Operating Leases, Future Minimum Payments, Due in Two Years	157,050,000,000
2015	48,863,000
Operating Leases, Future Minimum Payments, Due in Three Years	104,741,000,000
2016	50,544,000
Operating Leases, Future Minimum Payments, Due in Four Years	55,674,000,000
2017	25,812,000
Operating Leases, Future Minimum Payments, Due in Five Years	19,634,000,000
2018	5,400,000
Operating Leases, Future Minimum Payments, Due Thereafter	43,086,000,000
Capital Leases, Future Minimum Payments Due Thereafter		38,908,000
Operating Leases, Future Minimum Payments Due	590,959,000,000
Total minimum lease payments	218,045,000
Less: amounts representing interest	-17,039,000
Present value of minimum lease payments	201,006,000
Less: current portion	-42,902,000	-63,669,000
Capital lease obligations, long-term	158,104,000	107,846,000
2016	93,370,000
2017	60,269,000
2018	18,844,000
2019	0
Total	304,490,000
Fair Value, Estimate Not Practicable, Guarantees		400,000
Rental expense	229,290,000	180,328,000	149,433,000
Rent expense related to operating leases		$175,200,000	$144,600,000

Purchase_Commitments_Details

Purchase Commitments (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Commitments [Line Items]
Purchase Obligation, Due in Second and Third Year	$379.60
Percentage of options lapsed to cancel tractor purchase orders	13.00%
Outstanding purchase commitments for fuel, facilities and non-revenue equipment	3.2
Minimum [Member]
Commitments [Line Items]
Option to cancel tractor purchase orders	60 days
Maximum [Member]
Commitments [Line Items]
Option to cancel tractor purchase orders	90 days
Capital Addition Purchase Commitments [Member]
Commitments [Line Items]
Other Commitment, Due in Next Twelve Months	$791.30

Contingencies_Detail

Contingencies (Detail) (Other environmental [Member], USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Other environmental [Member]
Loss Contingencies [Line Items]
Range of possible loss, maximum	$1,000

Derivative_Financial_Instrumen2

Derivative Financial Instruments (Narrative) (Detail) (USD $)	0 Months Ended	12 Months Ended	0 Months Ended
In Millions, unless otherwise specified	Mar. 08, 2013	Dec. 31, 2014	Aug. 06, 2013	Apr. 30, 2011	Dec. 31, 2013
				Agreement
Derivatives, Fair Value [Line Items]
Deferred losses on derivatives in accumulated OCI expected to be reclassified to earnings within next 12 months		4
Central Refrigerated Service, Inc. [Member]
Derivatives, Fair Value [Line Items]
Repayments of debt	38
Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Number of interest rate derivatives held				2
Notional amount of interest rate swap agreements				350
Interest rate swaps agreement effective date		1-Jan-13
Interest rate swaps maturity date		1-Jul-15
Interest Rate Swaps [Member] | Central Refrigerated Service, Inc. [Member]
Derivatives, Fair Value [Line Items]
Fixed interest rate					8.90%
Repayments of debt			$0.30

Derivative_Financial_Instrumen3

Derivative Financial Instruments (Classification Of Gains And Losses On Interest Rate Derivative Contracts Designated As Hedging Instruments) (Detail) (USD $)	3 Months Ended										12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Derivative interest expense											$6,495,000	$3,852,000	$5,101,000
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	-4,000,000										-4,000,000
Income tax expense											89,474,000	100,982,000	61,614,000
Net income	58,491,000	50,158,000	40,198,000	12,305,000	45,298,000	29,953,000	49,879,000	[1]	30,292,000	[1]	161,152,000	155,422,000	140,087,000
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion											-6,218,000	-3,143,000	-5,101,000
Amount of loss recognized in OCI on derivatives, net-of-tax (effective portion)											0	145,000	2,786,000
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments											277,000	709,000	0
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Net income											3,998,000	1,917,000	7,090,000
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Derivative interest expense											6,218,000	3,143,000	5,101,000
Income tax expense											($2,220,000)	($1,226,000)	$1,989,000
[1]	The first and second quarter results of 2013 have been recast due to the acquisition of Central. Refer to Note1 for further information regarding the acquisition.

Equity_and_Stockbased_Compensa2

Equity and Stock-based Compensation (Compensation Expense Related To Stock-Based Compensation) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation expenses	$5,396	$4,645	$4,890
Income tax benefit	1,926	1,788	1,883
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation expenses	3,007	3,359	4,886
Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation expenses	1,600	887	4
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation expenses	$789	$399	$0

Equity_and_Stockbased_Compensa3

Equity and Stock-based Compensation (Compensation Costs Not Yet Recognized) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to nonvested options	$1,506
Expected weighted-average period for recognition for compensation cost	1 year 3 months 7 days
Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to the award	5,234
Expected weighted-average period for recognition for compensation cost	1 year 4 months 17 days
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to the award	$1,565
Expected weighted-average period for recognition for compensation cost	1 year 1 month 24 days

Equity_and_Stockbased_Compensa4

Equity and Stock-based Compensation (Summary Of Activity Related To Stock Options) (Detail) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Options, Outstanding [Roll Forward]
Shares Under Option, Outstanding at beginning of the year	4,785,133
Granted	175,142
Shares Under Option, Exercised	-1,100,998
Shares Under Option, Expired	-7,624
Shares Under Option, Forfeited	-86,779
Shares Under Option, Outstanding at end of the year	3,764,874		4,785,133
Shares Under Option, Aggregate number of stock options expected to vest at a future date at end of the year	1,485,666
Shares Under Option, Exercisable at end of the year	2,776,536
Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted Average Exercise Price, Outstanding at beginning of the year	$10.70
Weighted Average Exercise Price, Granted	$23.30
Weighted Average Exercise Price, Exercised	$10.43
Weighted Average Exercise Price, Expired	$10.14
Weighted Average Exercise Price, Forfeited	$12.47
Weighted Average Exercise Price, Outstanding at end of the year	$11.34		$10.70
Weighted Average Exercise Price, Aggregate number of stock options expected to vest at a future date at end of the year	$10.87
Weighted Average Exercise Price, Exercisable at end of the year	$10.63
Weighted Average Remaining Contractual Term, Outstanding at beginning of the year	4 years 8 months 5 days		5 years 3 months 10 days
Weighted Average Remaining Contractual Term, Aggregate number of stock options expected to vest at future date at the end of the year	6 years 3 months 7 days
Weighted Average Remaining Contractual Term, Exercisable	6 years 1 month 17 days
Aggregate Intrinsic Value, Outstanding at beginning of the year	$55,059	[1]
Aggregate Intrinsic Value, Outstanding at ending of the year	65,089	[1]	55,059	[1]
Aggregate Intrinsic Value, Aggregate number of stock options expected to vest at a future date at the end of year	16,846	[1]
Aggregate Intrinsic Value, Exercisable	$49,973	[1]
[1]	The aggregate intrinsic value was computed using the closing share price on December 31, 2013 of $22.21 and on December 31, 2012 of $9.12, as applicable.

Equity_and_Stockbased_Compensa5

Equity and Stock-based Compensation (Weighted Average Assumptions) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Equity [Abstract]
Dividend yield	0.00%	0.00%	0.00%
Risk-free rate of return	1.28%	1.04%	1.20%
Expected volatility	40.00%	40.80%	41.40%
Expected term (in years)	5 years 9 months 0 days	5 years 9 months 18 days	6 years 3 months 15 days
Weighted average fair value of stock options granted	$6.79	$5.90	$3.56

Equity_and_Stockbased_Compensa6

Equity and Stock-based Compensation (Summary Of Exercise Of Stock Options) (Detail) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Equity [Abstract]
Number of stock options exercised	1,100,998,000	1,210,184,000	24,427,000
Intrinsic value of stock options exercised	$15,830	$8,773	$25
Cash received upon exercise of stock options	11,488	12,985	268
Income tax benefit (deficiency) from exercise of stock options	$3,730	$187	($370)

Equity_and_Stockbased_Compensa7

Equity and Stock-based Compensation (Status of Nonvested Stock Options) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014
Options, Nonvested, Number of Shares [Roll Forward]
Granted	175,142
Stock Options [Member]
Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance, shares	1,606,588
Granted	175,142
Vested	-706,613
Forfeited	-86,779
Ending balance, shares	988,338
Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Beginning balance, weighted average fair value	4.66
Granted	6.79
Vested	4.46
Forfeited	3.88
Ending balance, weighted average fair value	4.02

Equity_and_Stockbased_Compensa8

Equity and Stock-based Compensation (Status Of Nonvested Shares) (Detail) (Restricted Stock Awards [Member], USD $)	12 Months Ended
	Dec. 31, 2014
Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares, Nonvested at beginning of the year	272,156
Shares, Granted	221,070
Shares, Vested	-98,866
Shares, Forfeited	-20,051
Shares, Nonvested at end of the year	374,309
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted Average Grand Date Fair Value, Nonvested at the beginning of the year	$16.20
Weighted Average Grand Date Fair Value, Granted	$23.24
Weighted Average Grand Date Fair Value, Vested	$16.12
Weighted Average Grand Date Fair Value, Forfeited	$19.87
Weighted Average Grand Date Fair Value, Nonvested at the end of the year	$19.95

Equity_and_Stockbased_Compensa9

Equity and Stock-based Compensation (Narrative) (Detail) (USD $)	12 Months Ended				0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2010	30-May-14	Dec. 31, 2013	Mar. 12, 2012	Mar. 08, 2013	Dec. 31, 2011	Oct. 29, 2013	Dec. 31, 2007
				Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Class B Shares Pledged	23,800,000
Additional VPF Shares	2,150,000
Options outstanding	3,764,874	4,785,133				4,785,133
Exercise Price	$11.34	$10.70				10.7
Number of categories of employees for stock options	2
Stock option plan, vesting period	3 years
Conversion basis of common shares	One-for-one
Non-cash equity compensation expense	$5,396,000	$4,645,000	$4,890,000
Income tax benefit	1,926,000	1,788,000	1,883,000
Maximum purchasing power of common stock for an employee during offering period		6,250
Maximum purchasing power of common stock for an employee during a calendar year		25,000
Maximum percent of total voting power or value of all classes of common stock which restricts from participation of ESPP		5.00%
2012 ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance		2,000,000				2,000,000
Employment period for eligibility of employees participation		90 days
Percentage of payroll deductions from employees compensation		15.00%				15.00%
Percentage of fair market value of the purchase price		95.00%
Number of shares purchased by the employees	50,788
Weighted-average fair value of the shares purchased	$21.96
Number of additional shares authorized for issuance	1,900,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum contractual term for the options granted	10 years
Stock option plan, vesting period	5 years
Vesting rights rate	33.33%
Total fair value of shares vested	3,200,000	4,000,000	10,000,000			4,000,000
Non-cash equity compensation expense	3,007,000	3,359,000	4,886,000
Unrecognized compensation cost related to nonvested options	1,506,000
Expected weighted-average period for recognition for compensation cost	1 year 3 months 7 days
IPO [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding									4,300,000
Exercise Price									$11
Number of employees holding options				1,100
Additional equity compensation expense				5,600,000
Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option plan, vesting period	3 years
Non-transferable period for selling shares	4 years
Shares, Granted	221,070
Non-cash equity compensation expense	1,600,000	887,000	4,000
Expected weighted-average period for recognition for compensation cost	1 year 4 months 17 days
Unrecognized compensation cost related to the award	5,234,000
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Requisite service period for performance shares	3 years
Non-cash equity compensation expense	789,000	399,000	0
Expected weighted-average period for recognition for compensation cost	1 year 1 month 24 days
Unrecognized compensation cost related to the award	1,565,000
Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Voting rights per share	1
Number Securities Pledged		23,800,000				23,800,000
Moyes VPF Shares Delivered to Citibank										19,500,000
Number of common shares converted					1,450,000	53,298	1,068,224
Number of shares issued per share converted	1
Class A Common Stock [Member] | 2007 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance											12,000,000
Class B Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Voting rights per share	2
Value Of Securities Pledged		262,300,000				262,300,000
Number of common shares converted					-1,450,000	-53,298	-1,068,224
Central Refrigerated Service, Inc. [Member] | Central Refrigerated Stockholder Loans Receivable, March 2013 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Loans granted under Stockholder Loan Agreement								$30,000,000

Income_Taxes_Income_Tax_Expens

Income Taxes (Income Tax Expense (Benefit) ) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current expense (benefit):
Federal	$81,117	($224)	$9,913
State	8,861	5,143	3,148
Foreign	4,107	1,530	1,949
Current expense (benefit), Total	94,085	6,449	15,010
Deferred expense (benefit):
Federal	-4,189	85,512	47,501
State	1,975	4,273	-2,010
Foreign	-2,397	4,748	1,113
Deferred expense (benefit), Total	-4,611	94,533	46,604
Income tax expense (benefit)	$89,474	$100,982	$61,614

Income_Taxes_Schedule_Of_Effec

Income Taxes (Schedule Of Effective Income Tax Rate Reconciliation) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Computed "expected" tax expense (benefit)	$87,719	$89,742	$70,595
State income taxes, net of federal income tax benefit	6,866	6,912	6,627
Pre acquisition earnings taxed as S-Corp	0	-4,986	-9,118
State tax rate change in deferred items	40	711	-6,414
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount	0	5,023	0
Effect of providing taxes on mark-to-market adjustment of derivatives recorded in accumulated OCI	0	0	1,785
Other	-5,151	3,580	-1,861
Income tax expense (benefit)	$89,474	$100,982	$61,614

Income_Taxes_Components_Of_Net

Income Taxes (Components Of Net Deferred Tax Asset (Liability) ) (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Operating Loss Carryforwards, Valuation Allowance	$400,000
Deferred tax assets:
Self insurance accruals	61,305,000	49,810,000
Allowance for doubtful accounts	9,561,000	6,968,000
Derivative financial instruments	2,350,000	4,537,000
Vacation accrual	4,342,000	3,899,000
Minimum tax credit	0	5,061,000
Net operating loss	2,507,000	4,529,000
Amortization of stock options	9,598,000	10,782,000
Other	16,040,000	17,259,000
Total deferred tax assets	105,703,000	102,845,000
Valuation allowance	0	0
Total deferred tax assets, net	105,703,000	102,845,000
Deferred tax liabilities:
Property and equipment, principally due to differences in depreciation	-401,963,000	-393,239,000
Prepaid taxes, licenses and permits deducted for tax purposes	-13,170,000	-12,897,000
Cancellation of debt	-7,503,000	-9,401,000
Intangible assets	-115,115,000	-119,567,000
Other	-5,345,000	-7,354,000
Total deferred tax liabilities	-543,096,000	-542,458,000
Net deferred tax liability	-437,393,000	-439,613,000
Deferred Tax Assets, Operating Loss Carryforwards, State and Local	$2,100,000

Income_Taxes_Current_Deferred_

Income Taxes (Current Deferred Tax Liability Included In Accrued Liabilities) (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]
Current deferred tax asset	$44,861	$46,833
Current deferred tax liability	-1,614	-2,246
Noncurrent deferred tax liability	-480,640	-484,200
Net deferred tax liability	($437,393)	($439,613)

Income_Taxes_Reconciliation_Of

Income Taxes (Reconciliation Of Unrecognized Tax Benefits) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Unrecognized tax benefits at beginning of year	$2,385	$2,385	$2,332
Increases for tax positions taken prior to beginning of year	95	0	149
Decreases for tax positions taken prior to beginning of year	-741	0	-53
Settlements	0	0	-43
Unrecognized tax benefits at end of year	$1,739	$2,385	$2,385

Income_Taxes_Narrative_Detail

Income Taxes (Narrative) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Tax Credit Carryforward [Line Items]
Current state tax expense	$8,861,000	$5,143,000	$3,148,000
Effective tax rate	35.70%	39.40%	30.50%
U.S. Federal corporate income tax rate	35.00%
Valuation allowance	0	0
Cumulative undistributed earnings of foreign subsidiaries	15,800,000
Additional tax payments	800,000
Interest and/or penalties expenses paid			400,000
Accrued interest and penalties	$1,300,000	$1,500,000	$1,300,000
Maximum [Member]
Tax Credit Carryforward [Line Items]
State net operating loss expiration year	2030
Minimum [Member]
Tax Credit Carryforward [Line Items]
State net operating loss expiration year	2015

Employee_Benefit_Plan_Detail

Employee Benefit Plan (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]
401(k) benefit plan, eligible age for employee	21 years
401(k) benefit plan, eligible criteria	6 months
Employee maximum contribution rate	3.00%
Employees' rights to employer contributions vesting period	5 years
Employer expenses	$4.70	$5.50	$5.60
Employer owed contribution	$4.90	$4.40

Key_Customer_Detail

Key Customer (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Entity Wide Portfolio Carrying Amount, Major Customer [Line Items]
Entity wide revenue, major customer, percentage	10.00%
Operating Revenue [Member] | Wal-Mart And Subsidiaries [Member]
Entity Wide Portfolio Carrying Amount, Major Customer [Line Items]
Entity wide revenue, major customer, percentage	11.00%	10.80%	11.40%

Related_Party_Transactions_Sch

Related Party Transactions (Schedule Of Services Received And Provided By Company) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Related Party Transaction [Line Items]
Due to Related Parties	$1		$75
Due from Related Parties	116		1,066
Freight Services [Member]
Related Party Transaction [Line Items]
Services Provided by Swift	224	[1]	175	[1]	9,382	[1]
Services Received by Swift	24		47		50
Facility Leases [Member]
Related Party Transaction [Line Items]
Services Provided by Swift	863		736		731
Services Received by Swift	628		599		626
Other Services [Member]
Related Party Transaction [Line Items]
Services Provided by Swift	392	[2]	1,159	[2]	135	[2]
Services Received by Swift	772	[3]	1,008	[3]	1,246	[3]
Central Freight Lines, Inc. [Member]
Related Party Transaction [Line Items]
Due to Related Parties	1		74
Due from Related Parties	93		1,034
Central Freight Lines, Inc. [Member] | Freight Services [Member]
Related Party Transaction [Line Items]
Services Provided by Swift	25	[1]	15	[1]	8,117	[1]
Services Received by Swift	24	[4]	47	[4]	50	[4]
Central Freight Lines, Inc. [Member] | Facility Leases [Member]
Related Party Transaction [Line Items]
Services Provided by Swift	843		716		711
Services Received by Swift	400		399		626
Central Freight Lines, Inc. [Member] | Other Services [Member]
Related Party Transaction [Line Items]
Services Provided by Swift	388	[2]	1,000	[2]	0	[2]
Services Received by Swift	0	[3]	0	[3]	0	[3]
Other Affiliated Entities [Member]
Related Party Transaction [Line Items]
Due to Related Parties	0		1
Due from Related Parties	23		32
Other Affiliated Entities [Member] | Freight Services [Member]
Related Party Transaction [Line Items]
Services Provided by Swift	199	[1]	160	[1]	1,265	[1]
Services Received by Swift	0		0		0
Other Affiliated Entities [Member] | Facility Leases [Member]
Related Party Transaction [Line Items]
Services Provided by Swift	20		20		20
Services Received by Swift	228		200		0
Other Affiliated Entities [Member] | Other Services [Member]
Related Party Transaction [Line Items]
Services Provided by Swift	4	[2]	159	[2]	135	[2]
Services Received by Swift	$772	[3]	$1,008	[3]	$1,246	[3]
[1]	The rates the Company charges for freight services to each of these companies for transportation services are market rates, which are comparable to what it charges third-party customers. These transportation services provided to affiliated entities provide the Company with an additional source of operating revenue at its normal freight rates.
[2]	Other services provided by the Company to the identified related parties included: equipment sales and miscellaneous services.
[3]	Other services received by the Company from the identified related parties included executive air transport, fuel storage, event fees, equipment purchases, miscellaneous repair services, and certain third-party payroll and employee benefits administration services.
[4]	Transportation services received from Central Freight represent LTL (less-than-truckload) freight services rendered to haul parts and equipment to Company shop locations. The rates paid to Central Freight for these loads are comparable to market rates charged by other non-affiliated LTL carriers.

Related_Party_Transactions_Nar

Related Party Transactions (Narrative) (Detail) (USD $)	12 Months Ended
In Thousands, except Share data in Millions, unless otherwise specified	Dec. 31, 2014
Related Party Transaction [Line Items]
Number of Class B Shares Pledged	23.8
Additional VPF Shares	2.15
William Riley III [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Purchases from Related Party	184
Increase (Decrease) in Due to Related Parties	23

Fair_Value_Measurement_Carryin

Fair Value Measurement (Carrying Amounts And Estimated Fair Values Of Financial Instruments) (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Assets	$24,510	$25,814
Carrying Value [Member] | 2014 Agreement, Term Loan A [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Liabilities Fair Value Disclosure	500,000	0
Carrying Value [Member] | 2014 Agreement, Term Loan B [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Liabilities Fair Value Disclosure	396,080	0
Carrying Value [Member] | Senior Second Priority Secured Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Liabilities	0	493,825
Carrying Value [Member] | Securitization Of Accounts Receivable [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Liabilities	334,000	264,000
Carrying Value [Member] | (2013 Agreement) [Member] | Senior Secured First Lien Term Loan B-1 Tranche [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Liabilities	0	229,000
Carrying Value [Member] | (2013 Agreement) [Member] | Senior Secured First Lien Term Loan B-2 Tranche [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Liabilities	0	410,000
Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Assets	24,502	25,808
Estimated Fair Value [Member] | 2014 Agreement, Term Loan A [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Liabilities Fair Value Disclosure	500,000	0
Estimated Fair Value [Member] | 2014 Agreement, Term Loan B [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Liabilities Fair Value Disclosure	390,436	0
Estimated Fair Value [Member] | Senior Second Priority Secured Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Liabilities	0	549,059
Estimated Fair Value [Member] | Securitization Of Accounts Receivable [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Liabilities	334,000	264,000
Estimated Fair Value [Member] | (2013 Agreement) [Member] | Senior Secured First Lien Term Loan B-1 Tranche [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Liabilities	0	230,031
Estimated Fair Value [Member] | (2013 Agreement) [Member] | Senior Secured First Lien Term Loan B-2 Tranche [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Liabilities	$0	$412,358

Fair_Value_Measurement_Liabili

Fair Value Measurement (Liabilities That Were Measured At Estimated Fair Value On Recurring Basis) (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Total Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps	$6,109	$11,768
Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps	6,109	11,768
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps	$0	$0

Fair_Value_Measurement_Assets_

Fair Value Measurement (Assets That Were Measured At Estimated Fair Value On Nonrecurring Basis) (Detail) (Other Assets [Member], USD $)	3 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Nonrecurring fair value gains and (losses)	($2,308)	[1]
Total Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets Fair Value	0
Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets Fair Value	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets Fair Value	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets Fair Value	$0
[1]	During 2014, certain operations software was replaced and the carrying value was determined to be fully impaired.

Fair_Value_Measurement_Narrati

Fair Value Measurement (Narrative) (Detail) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair Value Disclosures [Abstract]
Impairments on non-operating assets	$6,000	$0	$0	$5,979

Intangible_Assets_Schedule_Of_

Intangible Assets (Schedule Of Intangible Assets) (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Intangible Asset Excluding Goodwill [Line Items]
Intangible assets, net	$299,933	$316,747
Customer Relationships [Member]
Intangible Asset Excluding Goodwill [Line Items]
Gross carrying value	275,324	275,324
Accumulated amortization	-156,428	-139,614
Trade Names [Member]
Intangible Asset Excluding Goodwill [Line Items]
Gross carrying value	$181,037	$181,037

Intangible_Assets_Narrative_De

Intangible Assets (Narrative) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2007
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$16,814,000	$16,814,000	$16,925,000
Amortization expense by fiscal year maturity
2014	16,800,000
2015	16,800,000
2016	16,800,000
2017	16,300,000
2018	0
2007 Going private transaction [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying value				261,200,000
Amortization of intangible assets	15,600,000	15,600,000	15,800,000
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying value	275,324,000	275,324,000
Estimated useful life of intangible assets in years	15 years
2007 Prior To Going Private Transaction [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	1,200,000	1,200,000	1,200,000
Amortization expense by fiscal year maturity
2014	1,200,000
2015	1,200,000
2016	1,200,000
2017	600,000
2018	$0

Goodwill_Details

Goodwill (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Goodwill [Line Items]
Gross Carrying Amount	$507,740
Accumulated Impairment Losses	-254,484
Carry Amount	253,256	253,256
Truckload [Member]
Goodwill [Line Items]
Gross Carrying Amount	376,998
Accumulated Impairment Losses	-190,394
Carry Amount	186,604
Dedicated [Member]
Goodwill [Line Items]
Gross Carrying Amount	130,742
Accumulated Impairment Losses	-64,090
Carry Amount	$66,652

Earnings_Loss_Per_Share_Calcul

Earnings (Loss) Per Share (Calculation Of Basic And Diluted Earnings Per Share Attributable To Stockholders) (Detail) (USD $)	3 Months Ended										12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Earnings Per Share [Abstract]
Net income	$58,491	$50,158	$40,198	$12,305	$45,298	$29,953	$49,879	[1]	$30,292	[1]	$161,152		$155,422		$140,087
Basic:
Weighted average common shares outstanding											141,431		140,179		139,532
Diluted:
Dilutive effect of stock options											2,044		2,042		87
Total weighted average diluted shares outstanding											143,475		142,221		139,619
Anti-dilutive shares excluded from the diluted earnings per share calculation											162	[2]	174	[2]	4,356	[2]
Basic earnings per share	$0.41	$0.35	$0.28	$0.09							$1.14		$1.11		$1
Diluted earnings per share	$0.41	$0.35	$0.28	$0.09	$0.32	$0.21	$0.35	[1]	$0.21	[1]	$1.12		$1.09		$1
[1]	The first and second quarter results of 2013 have been recast due to the acquisition of Central. Refer to Note1 for further information regarding the acquisition.
[2]	(1)The impact of certain outstanding options to purchase shares of the Company’s Class A common stock were anti-dilutive because the options' exercise prices were greater than the average market prices of the common shares. These anti-dilutive shares were excluded from the calculation of diluted earnings per share.

Quarterly_Result_Of_Operations2

Quarterly Result Of Operations (unaudited) (Details) (USD $)	3 Months Ended										12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Selected Quarterly Financial Information [Abstract]
Revenues	$1,139,500	$1,074,880	$1,075,898	$1,008,446	$1,075,389	$1,032,127	$1,029,071	[1]	$981,608	[1]	$4,298,724	$4,118,195	$3,976,085
Operating income	132,467	97,411	94,022	46,170	102,555	84,420	100,266	[1]	69,718	[1]	370,070	356,959	351,816
Net income	$58,491	$50,158	$40,198	$12,305	$45,298	$29,953	$49,879	[1]	$30,292	[1]	$161,152	$155,422	$140,087
Basic earnings per share	$0.41	$0.35	$0.28	$0.09							$1.14	$1.11	$1
Basic and diluted earnings per share					$0.32	$0.21	$0.36	[1]	$0.22	[1]
Diluted earnings per share	$0.41	$0.35	$0.28	$0.09	$0.32	$0.21	$0.35	[1]	$0.21	[1]	$1.12	$1.09	$1
[1]	The first and second quarter results of 2013 have been recast due to the acquisition of Central. Refer to Note1 for further information regarding the acquisition.

Segment_Information_Narrative_

Segment Information (Narrative) (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	Segment
Segment Reporting [Abstract]
Number of Reportable Segments	4
Percentage of foreign operations total revenue	5.00%	5.00%	5.00%

Segment_Information_Summary_Of

Segment Information (Summary Of Financial Information By Segments) (Detail) (USD $)	3 Months Ended										12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Revenues	$1,139,500	$1,074,880	$1,075,898	$1,008,446	$1,075,389	$1,032,127	$1,029,071	[1]	$981,608	[1]	$4,298,724	$4,118,195	$3,976,085
Operating income	132,467	97,411	94,022	46,170	102,555	84,420	100,266	[1]	69,718	[1]	370,070	356,959	351,816
Depreciation and Amortization Expense											221,122	226,008	218,839
Truckload [Member]
Segment Reporting Information [Line Items]
Revenues											2,301,010	2,313,035	2,282,342
Operating income											258,072	225,963	246,005
Depreciation and Amortization Expense											113,875	127,404	121,004
Dedicated [Member]
Segment Reporting Information [Line Items]
Revenues											892,078	738,929	724,405
Operating income											75,794	83,520	74,026
Depreciation and Amortization Expense											53,682	45,568	44,088
CRS Refrigerated [Member]
Segment Reporting Information [Line Items]
Revenues											417,980	452,531	415,733
Operating income											14,035	17,682	21,334
Depreciation and Amortization Expense											12,510	13,926	14,539
Intermodal [Member]
Segment Reporting Information [Line Items]
Revenues											401,577	376,075	355,494
Operating income											8,298	5,619	-6,486
Depreciation and Amortization Expense											10,875	9,268	9,209
Subtotal [Member]
Segment Reporting Information [Line Items]
Revenues											4,012,645	3,880,570	3,777,974
Operating income											356,199	332,784	334,879
Depreciation and Amortization Expense											190,942	196,166	188,840
Nonreportable Segments [Member]
Segment Reporting Information [Line Items]
Revenues											342,969	287,853	268,821
Operating income											13,871	24,175	16,937
Depreciation and Amortization Expense											30,180	29,842	29,999
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues											($56,890)	($50,228)	($70,710)
[1]	The first and second quarter results of 2013 have been recast due to the acquisition of Central. Refer to Note1 for further information regarding the acquisition.

Settlement_City_of_Los_Angeles1

Settlement- City of Los Angeles (Details) (USD $)	0 Months Ended
In Millions, unless otherwise specified	Mar. 02, 2012
Disclosure Settlement City Of Los Angeles [Abstract]
Settlement agreement, term	5 years
Deferred revenue	$9.20
Amount refunded by the Company for damages that may be alleged by the City for breach or violation of the Amended Addendum	4
Recognized deferred revenue	$5.20