Knight Transportation 10-K 29 Feb 16 2015 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2015	Feb. 25, 2016	Jun. 30, 2015
Entity Registrant Name	KNIGHT TRANSPORTATION INC
Entity Central Index Key	929,452
Trading Symbol	knx
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	Yes
Entity Common Stock, Shares Outstanding (in shares)		80,655,035
Entity Public Float			$ 1.9
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Current Assets:
Cash and cash equivalents	$ 8,691,000	$ 17,066,000
Trade receivables, net of allowance for doubtful accounts of $3,106 and $3,355, respectively	131,945,000	143,531,000
Notes receivable, net of allowance for doubtful notes receivable of $273 and $351, respectively	648,000	1,020,000
Prepaid expenses	17,320,000	17,423,000
Assets held for sale	29,327,000	23,248,000
Other current assets	14,215,000	13,345,000
Income tax receivable	$ 41,967,000	19,432,000
Current deferred tax assets		3,187,000
Total current assets	$ 244,113,000	238,252,000
Property and Equipment:
Revenue equipment	866,252,000	803,410,000
Land and land improvements	52,951,000	52,531,000
Buildings and building improvements	139,102,000	125,492,000
Furniture and fixtures	18,363,000	17,322,000
Shop and service equipment	16,729,000	16,653,000
Leasehold improvements	3,061,000	3,037,000
Gross property and equipment	1,096,458,000	1,018,445,000
Less: accumulated depreciation and amortization	(292,815,000)	(266,399,000)
Property and equipment, net	803,643,000	752,046,000
Notes receivable, long-term	3,419,000	4,065,000
Goodwill	47,050,000	47,067,000
Intangible assets, net	3,075,000	3,575,000
Other long-term assets and restricted cash and investments	18,932,000	37,280,000
Total long-term assets	876,119,000	844,033,000
Total assets	1,120,232,000	1,082,285,000
Current Liabilities:
Accounts payable	14,818,000	19,122,000
Accrued payroll and purchased transportation	23,776,000	34,127,000
Accrued liabilities	21,609,000	20,604,000
Claims accrual – current portion	19,471,000	18,532,000
Dividend payable – current portion	349,000	200,000
Total current liabilities	80,023,000	92,585,000
Long-term Liabilities:
Claims accrual – long-term portion	11,508,000	11,505,000
Long-term dividend payable and other liabilities	2,164,000	2,513,000
Deferred tax liabilities	174,165,000	162,007,000
Long-term debt	112,000,000	134,400,000
Total long-term liabilities	299,837,000	310,425,000
Total liabilities	$ 379,860,000	$ 403,010,000
Commitments and Contingencies (Note 5)
Shareholders' Equity:
Preferred stock, $0.01 par value; 50,000 shares authorized; none issued	$ 0	$ 0
Common stock, $0.01 par value; 300,000 shares authorized; 80,967 and 81,842 shares issued and outstanding at December 31, 2015 and 2014, respectively	810,000	818,000
Additional paid-in capital	205,648,000	185,184,000
Accumulated other comprehensive income	2,573,000	12,231,000
Retained earnings	529,367,000	479,527,000
Total Knight Transportation shareholders' equity	738,398,000	677,760,000
Noncontrolling interest	1,974,000	1,515,000
Total shareholders' equity	740,372,000	679,275,000
Total liabilities and shareholders' equity	$ 1,120,232,000	$ 1,082,285,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	50,000,000	50,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, shares issued (in shares)	80,967,000	81,842,000
Common stock, shares outstanding (in shares)	80,967,000	81,842,000
Allowance for doubtful accounts	$ 3,106	$ 3,355
Allowance for doubtful notes receivable	$ 273	$ 351

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue:
Revenue, before fuel surcharge	$ 1,061,739	$ 925,985	$ 791,851
Fuel surcharge	121,225	176,347	177,386
Total revenue	1,182,964	1,102,332	969,237
Operating Expenses:
Salaries, wages and benefits	334,069	271,815	234,306
Fuel	152,752	203,758	214,843
Operations and maintenance	80,855	71,558	64,715
Insurance and claims	33,632	31,133	29,350
Operating taxes and licenses	18,911	17,972	15,624
Communications	4,095	4,899	5,015
Depreciation and amortization	111,023	92,893	86,129
Purchased transportation	246,864	238,041	189,667
Miscellaneous operating expenses	22,763	7,541	15,679
Total operating expenses	1,004,964	939,610	855,328
Income from operations	178,000	162,722	113,909
Other Income (Expense):
Interest income	460	458	413
Interest expense	(998)	(730)	(462)
Other income	9,042	9,380	2,844
Total other income	8,504	9,108	2,795
Income before income taxes	186,504	171,830	116,704
Income Taxes	68,047	67,809	46,680
Net income	118,457	104,021	70,024
Net income attributable to noncontrolling interest	(1,739)	(1,159)	(742)
Net income attributable to Knight Transportation	$ 116,718	$ 102,862	$ 69,282
Basic Earnings Per Share (in dollars per share)	$ 1.43	$ 1.27	$ 0.87
Diluted Earnings Per Share (in dollars per share)	$ 1.42	$ 1.25	$ 0.86
Weighted Average Shares Outstanding - Basic (in shares)	81,491	80,947	79,994
Weighted Average Shares Outstanding - Diluted (in shares)	82,467	82,042	80,330

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net income		$ 118,457	$ 104,021	$ 70,024
Other comprehensive income, net of tax:
Realized gains from available-for-sale securities reclassified to net income(1)	[1]	(5,273)	(1,932)	(1,189)
Unrealized (losses) gains from changes in fair value of available-for-sale securities(2)	[2]	(4,385)	9,581	6,073
Comprehensive income		108,799	111,670	74,908
Comprehensive income attributable to noncontrolling interest		(1,739)	(1,159)	(742)
Comprehensive income attributable to Knight Transportation		$ 107,060	$ 110,511	$ 74,166
[1]	Net of current income taxes of $3,318, $1,233, and $736, respectively.
[2]	Net of deferred income tax (benefits) expenses of $(2,870), $6,203, and $3,758, respectively.

Consolidated Statements of Com6

Consolidated Statements of Comprehensive Income (Parentheticals) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net of current income taxes	$ 3,318	$ 1,233	$ 736
Net of deferred income taxes	$ (2,870)	$ 6,203	$ 3,758

Consolidated Statements of Stoc

Consolidated Statements of Stockholders Equity - USD ($)	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Parent [Member]	Noncontrolling Interest [Member]	Total
Balance (in shares) at Dec. 31, 2012	79,760,000
Balance at Dec. 31, 2012	$ 798,000	$ 143,616,000	$ 348,213,000	$ (302,000)	$ 492,325,000	$ 608,000	$ 492,933,000
Exercise of stock options and RSUs (in shares)	429,000						345,302
Exercise of stock options and RSUs	$ 4,000	4,341,000			4,345,000		$ 4,345,000
Issuance of common stock (in shares)	10,000
Issuance of common stock		167,000			167,000		167,000
Shares withheld from RSU settlement			(739,000)		(739,000)		(739,000)
Excess tax benefit of stock option exercises		(81,000)			(81,000)		(81,000)
Employee stock-based compensation expense		2,815,000			2,815,000		2,815,000
Cash dividends paid and dividends accrued			(19,410,000)		(19,410,000)		(19,410,000)
Net income attributable to Knight			69,282,000		69,282,000		69,282,000
Other comprehensive income				4,884,000	4,884,000		4,884,000
Distribution to noncontrolling interest						(405,000)	(405,000)
Net income attributable to noncontrolling interest						742,000	742,000
Balance (in shares) at Dec. 31, 2013	80,199,000
Balance at Dec. 31, 2013	$ 802,000	150,858,000	397,346,000	4,582,000	553,588,000	945,000	$ 554,533,000
Exercise of stock options and RSUs (in shares)	1,634,000						1,551,400
Exercise of stock options and RSUs	$ 16,000	24,350,000			24,366,000		$ 24,366,000
Issuance of common stock	$ 9,000	200,000			200,000		200,000
Shares withheld from RSU settlement			(1,027,000)		(1,027,000)		(1,027,000)
Employee stock-based compensation expense		4,503,000			4,503,000		4,503,000
Cash dividends paid and dividends accrued			(19,654,000)		(19,654,000)		(19,654,000)
Net income attributable to Knight			102,862,000		102,862,000		102,862,000
Other comprehensive income				7,649,000	7,649,000		7,649,000
Distribution to noncontrolling interest						(589,000)	(589,000)
Net income attributable to noncontrolling interest						1,159,000	1,159,000
Balance (in shares) at Dec. 31, 2014	81,842,000
Balance at Dec. 31, 2014	$ 818,000	185,184,000	479,527,000	12,231,000	677,760,000	1,515,000	679,275,000
Excess tax benefit of stock option exercises		5,273,000			5,273,000		$ 5,273,000
Exercise of stock options and RSUs (in shares)	720,000						594,673
Exercise of stock options and RSUs	$ 8,000	9,923,000			9,931,000		$ 9,931,000
Issuance of common stock (in shares)	12,000
Issuance of common stock		354,000			354,000		354,000
Shares withheld from RSU settlement			(1,843,000)		(1,843,000)		(1,843,000)
Employee stock-based compensation expense		7,012,000			7,012,000		7,012,000
Cash dividends paid and dividends accrued			(19,706,000)		(19,706,000)		(19,706,000)
Net income attributable to Knight			116,718,000		116,718,000		116,718,000
Other comprehensive income				(9,658,000)	(9,658,000)		(9,658,000)
Distribution to noncontrolling interest						(1,280,000)	(1,280,000)
Net income attributable to noncontrolling interest						1,739,000	1,739,000
Balance (in shares) at Dec. 31, 2015	80,967,000
Balance at Dec. 31, 2015	$ 810,000	205,648,000	529,367,000	$ 2,573,000	738,398,000	$ 1,974,000	740,372,000
Excess tax benefit of stock option exercises		$ 3,175,000			3,175,000		3,175,000
Company shares repurchased (in shares)	(1,607,000)
Company shares repurchased	$ (16,000)		$ (45,329,000)		$ (45,345,000)		$ (45,345,000)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash Flows From Operating Activities:
Net income	$ 118,457	$ 104,021	$ 70,024
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation, Depletion and Amortization	111,023	92,893	86,129
Gain on sale of equipment	(15,346)	$ (16,840)	(7,550)
Earn-out on sold investment	(208)		(467)
Gain on sale of available-for-sale securities	(8,591)	$ (3,165)	(1,925)
Income from investment in Transportation Resource Partners III	(422)	(6,139)	(669)
Impairment of investment in Transportation Resource Partners	177	1,041	209
Compensation expense for issuance of common stock to certain members of board of directors	354	200	167
Provision for allowance for doubtful accounts and notes receivable	1,359	1,351	1,008
Deferred income taxes	21,532	17,060	$ (5,338)
Excess tax benefits related to stock-based compensation	(3,175)	(5,273)
Stock-based compensation expense	7,012	4,503	$ 2,815
Changes in operating assets and liabilities:
Trade receivables	10,266	(17,031)	(14,828)
Other current assets	(870)	(1,872)	1,384
Prepaid expenses	103	(1,647)	$ 2,008
Income tax receivable	(22,535)	(19,432)
Other long-term assets	(1,236)	442	$ (390)
Accounts payable	(8,543)	4,285	2,424
Accrued liabilities and claims accrual	(3,592)	22,790	3,517
Net cash provided by operating activities	205,765	177,187	138,518
Cash Flows From Investing Activities:
Purchases of property and equipment	(221,660)	(260,389)	(140,612)
Proceeds from sale of equipment/assets held for sale	$ 72,246	$ 81,555	55,244
Purchase of long-term available-for-sale securities			(10,035)
Cash proceeds from sale of available-for-sale securities	$ 12,528	$ 6,355	8,782
Cash receipt from notes receivable	$ 1,779	$ 2,309	2,383
Cash payment for notes receivable			(646)
Cash proceeds from related party notes receivable		$ 748	$ 1,570
Investment in Barr-Nunn Transportation	$ (3,500)	(110,517)
Cash payments to Transportation Resource Partners	(70)	(129)	$ (3,201)
Cash proceeds from Transportation Resource Partners	360	12,814	467
Change in restricted cash and investments	(18)	339	343
Net cash used in investing activities	(138,335)	(266,915)	(85,705)
Cash Flows From Financing Activities:
Dividends paid	(19,885)	(19,648)	$ (19,445)
Excess tax benefits related to stock-based compensation	3,175	5,273
(Payments of) proceeds from borrowing on line of credit, net	(22,400)	96,400	$ (42,000)
Cash distribution to noncontrolling interest holder	(1,280)	$ (589)	$ (405)
Payments to repurchase Company stock	(45,345)
Proceeds from exercise of stock options	9,930	$ 24,366	$ 4,345
Net cash (used in) provided by financing activities	(75,805)	105,802	(57,505)
Net (decrease) increase in Cash and Cash Equivalents	(8,375)	16,074	(4,692)
Cash and Cash Equivalents, beginning of year	17,066	992	5,684
Cash and Cash Equivalents, end of year	8,691	17,066	992
Non-cash investing and financing transactions:
Equipment acquired included in accounts payable	4,251	25	2,892
Dividend accrued for restricted stock units	178	196	205
Transfer from property and equipment to assets held for sale	49,786	56,521	40,422
Financing provided to independent contractors for equipment sold	787	1,579	1,731
Cash flow information:
Income taxes paid	65,594	68,020	51,904
Interest expense paid	$ 1,037	$ 666	$ 450

Note 1 - Organization and Summa

Note 1 - Organization and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Notes to Financial Statements
Significant Accounting Policies [Text Block]	Organization and Summary of Significant Accounting Policies a. Nature of Business Knight Transportation, Inc. (an Arizona corporation) and subsidiaries (the "Company") is a truckload carrier of general commodities and transportation logistics services provider headquartered in Phoenix, Arizona. The Company also has service centers located throughout the United States. The Company has two reportable segments, Trucking and Logistics. The Trucking segment provides truckload carrier dry van, temperature-controlled (refrigerated), and drayage services, and the Logistics segment provides logistics, freight management, brokerage, rail intermodal, and other non-trucking services. The Company is subject to regulation by the U.S. Department of Transportation, U.S. Environmental Protection Agency, U.S. Department of Homeland Security, and various state regulatory authorities. b. Significant Accounting Policies Principles of Consolidation - Use of Estimates - Cash and Cash Equivalents Notes Receivable The notes receivable balances are classified separately between current and long-term notes in the consolidated balance sheets. The current and long-term balances of our notes receivables as of December 31, 2015 and 2014 are as follows: 2015 2014 (in thousands) Notes receivable from independent contractors $ 794 $ 1,554 Notes receivable from third parties 3,546 3,882 Gross notes receivable 4,340 5,436 Allowance for doubtful notes receivable (273 ) (351 ) Total notes receivable, net of allowance $ 4,067 $ 5,085 Current portion, net of allowance 648 1,020 Long-term portion $ 3,419 $ 4,065 Assets Held for Sale Other Current Assets Property and Equipment - Years Land improvements 5 - 10 Buildings and improvements 10 - 30 Furniture and fixtures 3 - 10 Shop and service equipment 2 - 10 Revenue equipment 5 - 10 Leasehold improvements 1 - 5 To ensure that our facilities remain modern and efficient, we periodically have facility upgrades, or new construction, in process at our various service center locations or corporate headquarters. Until these projects are completed, we consider these to be assets not yet placed in service and they are not depreciated. Once they are placed into service, we depreciate them according to our depreciation policy. At December 31, 2015 and December 31, 2014, we had approximately $17.5 million and $6.9 million, respectively, of facility construction in process assets included under "Buildings and building improvements” on the accompanying consolidated balance sheets. The Company expenses repairs and maintenance as incurred. For the years ended December 31, 2015, 2014, and 2013, repairs and maintenance expense totaled approximately $33.4 million, $30.9 million, and $30.5 million, respectively. The expense is included in “Operations and maintenance” expense in the accompanying consolidated statements of income. The Company periodically reviews the reasonableness of its estimates regarding useful lives and salvage values for revenue equipment and other long-lived assets based upon, among other things, the Company's experience with similar assets, conditions in the used revenue equipment market, and prevailing industry practice. Tires on revenue equipment purchased are capitalized as a part of the equipment cost and depreciated over the life of the vehicle. Replacement tires and recapping costs are expensed when placed in service. Other Long-term Assets and Restricted Cash and Investments include 2015 2014 (in thousands) Investment in Transportation Resource Partners (TRP) $ 300 $ 477 Investment in Transportation Resource Partners III (TRP III) 5,752 5,412 Restricted Cash and Investments 3,282 3,264 Available-For-Sale Equity Securities 7,101 26,884 Other 2,497 1,243 $ 18,932 $ 37,280 In 2003, the Company signed a partnership agreement with TRP, a company that makes privately negotiated equity investments. According to the original partnership agreement, the Company committed to invest $5.0 million out of approximately $260.0 million total, for a 1.9% ownership interest. In early 2006, the Company increased the commitment amount to $5.5 million. Contributions to TRP are accounted for using the cost method as the level of influence over the operations of TRP is minor, and no contributions have been made to TRP since 2011. In 2015, the Company recorded gains and received distributions totaling $208,000. In 2014, distributions of $2.1 million were received and a $1.6 million gain was recorded, while in 2013, distributions received and gains recorded were $467,000. The gains are recognized in the year distributions are received. The Company also recorded impairment of $177,000, $1.0 million and $209,000 in 2015, 2014, and 2013, respectively, for other-than-temporary loss on the investments remaining within the TRP portfolio. The Company's ownership interest in TRP is approximately 2.2%, with a carrying value of $300,000 and $477,000 at December 31, 2015 and 2014, respectively. In the fourth quarter of 2008, the Company committed to invest $15.0 million in a new partnership managed and operated by the managers and principals of TRP. The new partnership, TRP III, focuses on the same investment opportunities as TRP. Since its inception, the Company has contributed approximately $11.0 million to TRP III.In June 2015, based on an analysis of expected future fund activity, TRP III released investors from a portion of their outstanding commitment. The Company’s share of the commitment release was $2.1 million leaving an outstanding commitment of $1.9 million as of December 31, 2015. The investment in TRP III is accounted for using the equity method. The Company has recorded income of approximately $422,000, $6.1 million, and $669,000 for its investment in TRP III for years ended December 31, 2015, 2014, and 2013, respectively. In 2015, the Company received distributions totaling $152,000 from TRP III for the sale of TRP III portfolio companies. At December 31, 2015, the investment balance in TRP III was $5.8 million, compared to $5.4 million at December 31, 2014. The Company's ownership interest was approximately 6.1% as at December 31, 2015. In the third quarter of 2015, the Company committed to invest in a new partnership, TRP Capital Partners, LP (TRP IV”). The new partnership is managed and operated by the managers and principals of TRP and TRP III, and is focused on similar investment opportunities. The Company committed to contribute a total of $4.9 million to the new partnership, and has contributed $41,000 as of December 31, 2015. Since the year-end, the Company has committed to invest in another TRP partnership, TRP CoInvest Partners (NTI) I, LP. This new partnership is also operated and managed by the managers and principals of TRP and TRP III, and is focused on similar investment opportunities. The Company committed to contribute a total of $10.0 million to the new partnership, and fulfilled its commitment in February 2016. Restricted Cash and Investments – In accordance with the provisions of ASC 210, Balance Sheet Investments – Debt and Equity Securities Impairment of Long-Lived Assets – Property, Plant and Equipment Long-lived Assets Goodwill & Intangibles, net Goodwill In 2015, the Company changed the date of the annual impairment testing to June 30 from September 30. This change did not result in the delay, acceleration or avoidance of an impairment charge. The Company believes this change in accounting principle is preferable because it better aligns with the Company’s annual strategic and planning process and alleviates administrative burden during the year-end reporting period. This change to the annual goodwill impairment testing was applied prospectively and had no effect on these consolidated financial statements. This change was not applied retrospectively as it is impractical to do so because retrospective application would have required the application of significant estimates and assumptions without use of hindsight. The Company completed this annual test as of June 30, 2015, and September 30, 2014, and no adjustment for impairment was determined to be necessary. In conjunction with the acquisition of Roads West in 2006, the basis of goodwill for tax purposes was determined to be in excess of the book basis of goodwill. Under this circumstance, ASC 740, Income Taxes Business Combination The changes in the carrying amounts of goodwill were as follows: 2015 2014 (in thousands) Goodwill at beginning of period $ 47,067 $ 10,257 Acquisition - 36,835 Amortization relating to deferred tax assets (17 ) (25 ) Goodwill at end of period $ 47,050 $ 47,067 Identifiable intangible assets subject to amortization relate to customer relations and trade names acquired through the 2014 acquisition of Barr-Nunn Transportation, Inc. and certain of its affiliates (“Barr-Nunn”). The intangible assets acquired were recorded at fair value at the date of acquisition. Intangible asset balances were as follows: 2015 2014 (in thousands) Gross carrying amount $ 3,700 $ 3,700 Accumulated amortization (625 ) (125 ) Intangible assets, net $ 3,075 $ 3,575 These intangible assets are being amortized over a weighted average amortization period of 7.6 years. Amortization expense associated with these intangible assets was $0.5 million, and $0.1 million for the year ended December 31, 2015, and December 31, 2014, respectively, and was included in depreciation and amortization expense in the accompanying consolidated statements of income. Future amortization expense for intangible assets is estimated at $0.5 million for 2016 through 2019, and $0.4 million in 2020. Claims Accrual - Revenue Recognition - In accordance with ASC 605-45, Revenue Recognition – Principal Agent Consideration Allowance for Doubtful Accounts Allowance for Doubtful Notes Receivable Income Taxes The Company records a valuation allowance for deferred tax assets to the extent it believes these assets are not more likely than not to be realized. In making such determinations, the Company considers all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax planning strategies, and recent financial operations. A valuation allowance for deferred tax assets has not been deemed necessary due to the Company's profitable operations. The Company recognizes a tax benefit from an uncertain tax position when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits. Financial Instruments The Company's financial instruments include cash equivalents, investments held for trading, available-for-sale securities, trade receivables, notes receivable, accounts payable and long-term debt. Due to the short-term nature of cash equivalents, trade receivables, and accounts payable, the fair value of these instruments approximates their recorded value. Available-for-sale and trading securities consist of marketable equity and debt securities stated at fair value. Due to the variable interest rate, the carrying value of long-term debt approximates fair value. Concentration of Credit Risk - Earnings Per Share 2015 2014 2013 Net Income ( numerator ) Shares ( denominator ) Per Share Amount Net Income ( numerator ) Shares ( denominator ) Per Share Amount Net Income ( numerator ) Shares ( denominator ) Per Share Amount Basic EPS $ 116,718 81,491 $ 1.43 $ 102,862 80,947 $ 1.27 $ 69,282 79,994 $ 0.87 Effect of stock options & restricted stock - 976 - 1,095 - 336 Diluted EPS $ 116,718 82,467 $ 1.42 $ 102,862 82,042 $ 1.25 $ 69,282 80,330 $ 0.86 Certain shares of options, restricted stock units, and performance restricted stock units (“equity awards”) were excluded from the computation of diluted earnings per share because the equity award’s exercise prices were greater than the average market price of the common shares and the sum total of assumed proceeds resulted in fewer shares repurchased than the weighted equity awards outstanding hypothetically exercised per the treasury method. A summary of those shares for the years ended December 31, 2015, 2014, and 2013, respectively, is as follows: 2015 2014 2013 Number of anti-dilutive shares 387,969 232,803 1,917,020 New Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). This update seeks to increases the transparency and comparability among entities by requiring public entities to recognize lease assets and lease liabilities on the balance sheet and disclose key information about leasing arrangements. To satisfy the standard’s objective, a lessee will recognize a right-of-use asset representing its right to use the underlying asset for the lease term and a lease liability for the obligation to make lease payments. Both the right-of-use asset and lease liability will initially be measured at the present value of the lease payments, with subsequent measurement dependent on the classification of the lease as either a finance or an operating lease. For leases with a term of 12 months or less, a lessee is permitted to make an accounting policy election by class of underlying asset not to recognize lease assets and lease liabilities. If a lessee makes this election, it should recognize lease expense for such leases generally on a straight-line basis over the lease term. Accounting by lessors will remain mostly unchanged from current U.S. GAAP. In transition, lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The modified retrospective approach includes a number of optional practical expedients that companies may elect to apply. These practical expedients relate to the identification and classification of leases that commenced before the effective date, initial direct costs for leases that commenced before the effective date, and the ability to use hindsight in evaluating lessee options to extend or terminate a lease or to purchase the underlying asset. The transition guidance also provides specific guidance for sale and leaseback transactions, build-to-suit leases, leveraged leases, and amounts previously recognized in accordance with the business combinations guidance for leases. The new standard is effective for public companies for annual periods beginning after December 15, 2018, and interim periods within those years, with early adoption permitted. The Company is currently evaluating the effect that adopting this standard will have on the Company’s consolidated financial statements. In January 2016, the FASB issued ASU 2016-01, Financial Instruments–Overall (Subtopic 825-10).This update was issued to enhance the reporting model for financial instruments regarding certain aspects of recognition, measurement, presentation, and disclosure. The update (i) requires equity investments (except those accounted for under the equity method or that are consolidated) to be measured at fair value with changes in fair value recognized in net income; (ii) simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment; (iii) eliminates the requirement for an entity to disclose the methods and significant assumptions used to estimate the fair value of financial instruments measured at amortized cost; (iv) requires an entity to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes; and (v) requires separate presentation of financial assets and financial liabilities by measurement category and form of financial asset on the balance sheet or in the accompanying notes to the financial statements. These provisions are effective for annual reporting periods beginning after December 15, 2017, and interim periods within those annual periods. The standard is to be applied using a cumulative-effect adjustment to the balance sheet as of the beginning of the year of adoption. The Company is currently evaluating the effect that adopting this standard will have on the Company’s consolidated financial statements. In November 2015, the FASB issued ASU 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes. In June 2014, the FASB issued ASU 2014-12, Stock Compensation - Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers

Note 2 - Fair Value Measurement

Note 2 - Fair Value Measurements	12 Months Ended
	Dec. 31, 2015
Notes to Financial Statements
Fair Value Disclosures [Text Block]	2. Fair Value Measurements US GAAP has established a framework for measuring fair value and a fair value hierarchy based on the inputs used to measure fair value. This framework maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the observable inputs be used when available. Fair value is defined as the price 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. Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from independent sources. Unobservable inputs reflect assumptions that market participants would use in pricing the asset or liability based on the best information available in the circumstances. The hierarchy is broken down into three levels based on the transparency of inputs as follows: Level 1 – Inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. An active market is defined as a market in which transactions for the assets or liabilities occur with sufficient frequency and volume to provide pricing information on an ongoing basis. Level 2 – Inputs include quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active (markets with few transactions), inputs other than quoted prices that are observable for the asset or liability ( i.e. Level 3 – Unobservable inputs, only used to the extent that observable inputs are not available, reflect the Company's assumptions about the pricing of an asset or liability. In accordance with the fair value hierarchy described above, the following table shows the fair value of the Company's financial assets and liabilities that are required to be measured on a recurring basis at fair value as of December 31, 2015 and December 31, 2014. Level One Level Two Level Three Balance at December 31, 2015 Balance at December 31, 2014 Balance at December 31, 2015 Balance at December 31, 2014 Balance at December 31, 2015 Balance at December 31, 2014 Balance at December 31, 2015 Balance at December 31, 2014 (in thousands) Assets: Available-for-sale Securities: Equity securities - common shares $ 7,101 $ 26,884 $ 7,101 $ 26,884 - - - - Restricted cash and investments: Money market funds $ 1,003 $ 1,027 $ 1,003 $ 1,027 - - - - Trading Securities: Debt securities - municipal securities $ 2,279 $ 2,237 - - $ 2,279 $ 2,237 - - The Company has certain marketable equity securities classified as available-for-sale securities, which are recorded at fair value with unrealized gains and losses, net of tax, as a component of "Accumulated other comprehensive income" in shareholders' equity in the accompanying consolidated balance sheets. Realized gains and losses on available-for-sale securities are included in the determination of net income. The Company uses specific identification to determine the cost of securities sold, and amounts reclassified out of accumulated other comprehensive income into earnings. The following table shows the Company’s realized gains during the years ended December 31, 2015, 2014, and 2013, on certain securities that were held as available-for-sale. The cost of securities sold is based on the specific identification method and included in “Other income” in the accompanying consolidated statements of income. December 31, 2015 2014 2013 (in thousands) Sales proceeds $ 12,528 $ 6,355 $ 8,782 Cost of securities sold 3,937 3,190 6,857 Realized gain $ 8,591 $ 3,165 $ 1,925 Realized gains, net of taxes $ 5,273 $ 1,932 $ 1,189 As of December 31, 2015, the available-for-sale equity investments included in "Other long-term assets and restricted cash and investments" in the accompanying consolidated balance sheets was approximately $7.1 million, including gross unrealized gains of approximately $4.2 million, or $2.6 million (net of tax). As of December 31, 2014, the available-for-sale investment balance was approximately $26.9 million, including gross unrealized gains of approximately $20.0 million, or $12.2 million (net of tax). The cost basis of these investments at December 31, 2015, and 2014, is approximately $2.9 million and $6.9 million, respectively.

Note 3 - Line of Credit and Lon

Note 3 - Line of Credit and Long-term Debt	12 Months Ended
	Dec. 31, 2015
Notes to Financial Statements
Long-term Debt [Text Block]	3. Line of Credit and Long-Term Debt The Company maintained a revolving line of credit with Wells Fargo Bank, which permitted revolving borrowings and letters of credit. The line of credit is maintained at $300.0 million, and matures December 1, 2017. Interest is incurred on borrowings under the line of credit at either the prime rate, or LIBOR plus 0.625%, determined at the time of borrowing. The Company had $112.0 million and $134.4 million outstanding under the line of credit as of December 31, 2015 and 2014, respectively. The weighted average variable annual percentage rate ("APR") for amounts borrowed in 2015 was 0.88%, and 0.91% for amounts borrowed in 2014. Borrowing under the line of credit is recorded in the "Long-term debt" line of the accompanying consolidated balance sheets. In connection with the Company’s self-insurance program, as of December 31, 2015, the Company also utilized $27.4 million of the line of credit for letters of credit issued to various regulatory authorities. The Company has $160.6 million available for future borrowings at December 31, 2015. After consideration of fees incurred for the unused portion of our line of credit, our weighted average variable annual percentage rate ("APR") for the year ended December 31, 2015 was 1.05%, and 1.31% for the year ended December 31, 2014. The Company is obligated to comply with certain financial and other covenants under the line of credit agreement and was in compliance with such covenants at December 31, 2015 and December 31, 2014.

Note 4 - Income Taxes

Note 4 - Income Taxes	12 Months Ended
	Dec. 31, 2015
Notes to Financial Statements
Income Tax Disclosure [Text Block]	4. Income Taxes Income tax expense consisted of the following (in thousands): 2015 2014 2013 Current income taxes: Federal $ 41,549 $ 42,101 $ 46,445 State 4,966 8,648 5,573 46,515 50,749 52,018 Deferred income taxes: Federal 19,666 12,644 (5,520 ) State 1,866 4,416 182 21,532 17,060 (5,338 ) $ 68,047 $ 67,809 $ 46,680 The effective income tax rate is different than the amount that would be computed by applying statutory corporate income tax rates to income before income taxes. The differences are summarized as follows (in thousands): 2015 2014 2013 Tax at the statutory rate (35%) $ 65,277 $ 60,141 $ 40,846 State income taxes, net of federal benefit 4,441 8,492 3,804 Nondeductible driver per diem 1,982 1,885 1,807 Other, net (3,653 ) (2,709 ) 223 $ 68,047 $ 67,809 $ 46,680 The net effect of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities at December 31, 2015 and 2014 are as follows (in thousands): 2015 2014 Short-term deferred tax assets (liabilities): Claims accrual - $ 6,322 Investments - (2,066 ) Prepaid expenses deducted for tax purposes - (2,952 ) Other, net - 1,883 Short-term deferred tax assets, net - $ 3,187 Long-term deferred tax liabilities (assets): Property and equipment depreciation $ 185,678 $ 161,209 Claims accrual (10,578 ) (4,482 ) Stock options (3,837 ) (2,847 ) Investments 582 7,807 Prepaid expenses deducted for tax purposes 2,947 - Other, net (627 ) 320 Long-term deferred liabilities, net $ 174,165 $ 162,007 For the years ended December 31, 2015, 2014, and 2013, the Company does not have any uncertain tax positions, nor any unrecognized tax benefits based upon an analysis of the Company's historic and future tax positions. There are no tax uncertainties for which it is reasonably possible an amount of unrecognized tax benefit should be recognized. Unrecognized tax benefits are defined as the difference between a tax position taken or expected to be taken in a tax return and the benefit recognized and measured pursuant to ASC Topic 740. The Company files federal and state income tax returns with varying statutes of limitations. The 2012 through 2015 tax years generally remain subject to examination by the federal authority, and the 2011 through 2015 tax years generally remain subject to examination by state tax authorities. The Company does not believe the unrecognized tax benefits will change significantly over the next 12 months. Historically, in accordance with GAAP, the Company presented deferred tax assets and liabilities separately in current amounts and non-current amounts on the basis of the classification of the related asset or liability for financial reporting. Deferred tax assets and liabilities that are not related to an asset or liability for financial reporting, are classified according to the expected reversal date of the temporary difference. On November 20, 2015 the FASB issued an amendment to the current standard, ASU 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes

Note 5 - Commitments and Contin

Note 5 - Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	5. Commitments and Contingencies a. Purchase Commitments The Company's purchase commitments for 2016 total $103.0 million, which primarily consists of revenue equipment, net of equipment trade-ins from contracted vendors, and a carry forward of approximately $7.1 million from 2015 contracts. The Company generally has the option to cancel with advanced notice ranging from 9 weeks to 90 days prior to the scheduled production. b. Investment Commitments The Company's commitment to invest in TRP is $5.5 million. The Company's commitment to invest in TRP III is $15.0 million. As of December 31, 2015, the Company has contributed approximately $11.0 million to TRP III, and $2.1 million was released leaving an outstanding commitment of $1.9 million as of December 31, 2015. The Company’s commitment to invest in TRP IV is $4.9 million, and $41,000 has been contributed as of December 31, 2015. The Company’s commitment to invest in TRP CoInvest Partners (NTI) I, LP is $10.0 million, and the Company contributed $10.0 million in February 2016. c. Operating Leases The Company periodically leases revenue equipment, certain service center building facilities, and communication equipment under non-cancelable operating leases. The Company also has operating leases for trailer storage. Operating lease expense under operating leases was approximately $4.7 million, $2.8 million, and $2.2 million for the years ended December 31, 2015, 2014, and 2013, respectively. Operating lease expense is included as an operating expense under "Miscellaneous operating expenses" in the consolidated statements of income. Future minimum lease payments under non-cancelable operating leases as of December 31, 2015 are as follows: Year Ending December 31, Amount (in thousands) 2016 $ 3,242 2017 3,172 2018 1,684 2019 213 2020 219 2021 36 Total $ 8,566 d. Other The Company is involved in certain claims and pending litigation arising in the normal course of business. These proceedings primarily involve claims for personal injury or property damage incurred in the transportation of freight or for personnel matters. The Company maintains insurance to cover liabilities arising from the transportation of freight in amounts in excess of self-insurance retentions, and accrues for estimated self-insured claims liabilities as described in Note 6. Based on present 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 materially adverse effect on the Company's financial position or results of operations. However, the final disposition of these matters and the impact of such final dispositions cannot be determined at this time. The Company is also involved in certain class action litigation in which the plaintiffs allege claims for failure to provide meal and rest breaks, unpaid wages, unauthorized deductions and other items. The Company is a defendant in a class action lawsuit which was filed on May 8, 2008, in the California Superior Court for Tulare County. The plaintiffs, who are current and former drivers and who worked for the Company during the period of May 8, 2004 through August 6, 2015, allege claims for failure to provide meal periods, inaccurate itemized pay statements and other items under the California Labor Code. During the second quarter of 2015, the Company reached a preliminary settlement with the plaintiffs, and in December 2015, the court issued final approval of the settlement. The Company is also a defendant in a class action lawsuit that was filed on June 10, 2010, in the Oregon Circuit Court for Multnomah County. The plaintiffs, who are current and former drivers who worked for the Company during the period of June 10, 2004 through June 10, 2010, allege the Company failed to pay minimum wage for attending pre-employment orientation and failed to pay minimum wage for work performed during certain pay periods after the start of employment. On July 2, 2015, the court, following a bench trial, issued a decision finding that the Company failed to pay minimum wage to some class members for work performed during certain pay periods and assessed statutory penalties and prejudgment interest related to our failure to comply with minimum wage obligations. In the fourth quarter of 2015, the Company reached a preliminary settlement with the plaintiffs and the current and former drivers who worked for the Company during the period June 11, 2010 through September 30, 2015. In December 2015, the court issued final approval of the settlement. As a result of the California settlement and the Oregon decision, during the second quarter of 2015, the Company accrued a total of $7.2 million, including the plaintiffs’ estimated attorneys’ fees and related costs and excluding attorneys’ fees and costs related to our defense, in our condensed consolidated financial statements. The Company had previously accrued $0.2 million as of December 31, 2014 related to these cases. Based on claims resolved this year, and the Company’s present knowledge of the facts and in certain cases, advice of outside counsel, management believes the resolution of open claims and pending litigation, taking into account existing reserves, is not likely to have a materially adverse effect on our consolidated financial statements.

Note 6 - Claims Accrual

Note 6 - Claims Accrual	12 Months Ended
	Dec. 31, 2015
Notes to Financial Statements
Claims Accrual [Text Block]	6. Claims Accrual The primary claims arising for the Company consist of auto liability (personal injury and property damage), cargo liability, collision, comprehensive and workers' compensation. The Company is insured against auto liability claims under a SIR policy with retention ranging from $1.0 million to $3.0 million per occurrence and in some years, depending on the applicable policy year, the Company has been responsible for aggregate losses up to $1.5 million. For the policy periods February 1, 2014 to March 1, 2015 and March 1, 2015 to March 1, 2016, the Company's SIR is $2.5 million with no additional responsibility for "aggregate" losses. The Company is also self-insured for workers' compensation coverage, with a self-retention level of a maximum $500,000 per occurrence. The Company establishes reserves to cover these self-insured liabilities and maintains insurance to cover liabilities in excess of those amounts. The Company's insurance policies provide for excess personal injury and property damage liability up to a total of $105.0 million per occurrence, which also includes a separate $2.5 million dollar aggregate deductible. The Company also maintains excess coverage for employee medical expenses and hospitalization. The self- retention amount for employee medical health was $225,000 per claimant for 2015 and 2014, and will be $240,000 per claimant for 2016. The Company's claims reserves are classified separately between current and long-term in the balance sheet. The current and long-term balance of the Company's claims reserves at December 31, 2015 and 2014 are as follows: 2015 2014 (in thousands) Auto reserves $ 18,926 $ 18,075 Workers' compensation reserves 8,815 8,728 Employee medical reserves 3,238 3,234 Total reserves $ 30,979 $ 30,037 Current portion $ 19,471 $ 18,532 Long-term portion $ 11,508 $ 11,505 A reconciliation of the beginning and ending amount of the Company's claims reserves for the years ended December 31, 2015 and 2014 is as follows: 2015 2014 (in thousands) Beginning Balance $ 30,037 $ 24,505 Acquisition (1) - 3,209 Provisions recorded 52,031 49,135 Claims paid and direct expenses (51,089 ) (46,812 ) Total reserves $ 30,979 $ 30,037 (1) Addition to claims reserve following acquisition of Barr-Nunn. The provision recorded for the year ended December 31, 2015, is comprised of $33.4 million for insurance and claims expense, which is included in the "Insurance and claims" line of the consolidated statements of income, $7.9 million for workers' compensation expense , and $10.7 million for medical expense, both of which are included in the "Salaries, wages and benefits" line of the consolidated statements of income. The provision recorded for the year ended December 31, 2014, is comprised of $30.9 million for insurance and claims expense, $7.8 million for workers' compensation expense, and $10.4 million for medical expense.

Note 7 - Shareholders' Equity

Note 7 - Shareholders' Equity	12 Months Ended
	Dec. 31, 2015
Notes to Financial Statements
Stockholders' Equity Note Disclosure [Text Block]	7. Shareholders' Equity During 2015, 2014, and 2013, certain non-employee Board of Director members received annual director fees through the issuance of common stock in equivalent shares. The table below reflects this activity for the years as presented. 2015 2014 2013 Annual director fees paid through stock issuance $ 354,168 $ 200,484 $ 167,946 Shares of common stock issued 11,853 8,828 9,885 Dividends paid per common share $ 0.24 $ 0.24 $ 0.24

Note 8 - Stock-Based Compensati

Note 8 - Stock-Based Compensation and Employee Benefit Plans	12 Months Ended
	Dec. 31, 2015
Notes to Financial Statements
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]	8. Stock Based Compensation and Employee Benefit Plans a. Stock-Based Compensation In May 2015, our shareholders approved the Amended and Restated 2015 Omnibus Incentive Plan (the “2015 Plan”). This plan combines into a single plan the Company’s 2005 Executive Cash Bonus Plan (the “2005 Plan”) and the 2012 Equity Compensation Plan (the “2012 Plan”) and allows for future grants under the 2015 Omnibus Incentive Plan. Grants outstanding under the 2005 Plan and 2012 Plan will continue in force and effect and continue to be governed solely by the terms and conditions of the instrument evidencing such grants, and will be interpreted under the terms of the 2005 Plan and the 2012 Plan, as applicable. Since approval of the 2015 Omnibus Incentive Plan in May 2015, all grants of stock-based compensation are made under the 2015 Omnibus Incentive Plan. The 2015 Plan is administered by the Compensation Committee of the Board of Directors (the "Compensation Committee"). The Compensation Committee has discretion to determine the number of shares subject to each grant and the terms and conditions of each grant, subject to the general limitations of the 2015 Plan, but in any calendar year, no single grant may exceed 650,000 shares. The Compensation Committee may award cash bonuses, incentive stock options, non-qualified stock options, restricted stock grants, restricted stock units, performance based restricted stock units, stock appreciation rights, or other incentive Awards permitted by the 2015 Plan to employees and officers. Incentive stock options are designed to comply with the applicable provisions of the Internal Revenue Code (the "Code") and are subject to restrictions within the Code. Vesting schedules for grants are set by the Compensation Committee and vary according to the goals of the grant. Grants, including stock options, must be granted with exercise price equal to the fair market value, determined by the closing price of the stock on the date the grant is made, as reported by the New York Stock Exchange. The exercise price of stock options granted may not be modified. Most stock options granted by the Company cannot be exercised until at least one (1) year after the date of grant and are forfeited upon termination of employment for reasons other than death, disability, or retirement. The 2015 Plan reserved 3,250,000 shares for the grant of equity compensation awards. The 2015 Plan will expire on May 13, 2025. Under the 2015 Plan, the Compensation Committee is authorized to issue Awards of Common Stock to Directors as compensation for their services. In the past director compensation was paid 50% by cash and 50% by stock. In 2015, the Compensation Committee adopted a new Directors Equity Grant Policy which allows directors to elect to receive in excess of 50% of their total compensation in stock, up to 100%. Directors who are our officers or employees or 10% shareholders do not receive compensation for Board or Board committee service. Stock awards issued to directors are valued at the closing price of our Common Stock on the date of the grant. Stock-based compensation charges were approximately $7.0 million, $4.5 million, and $2.8 million for the years ended December 31, 2015, 2014, and 2013, respectively, which reduced income from operations accordingly. Stock-based compensation expense recognized is based on awards ultimately expected to vest and has been reduced for estimated forfeitures. ASC 718 requires forfeitures to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. The Company received $9.9 million, $24.4 million, and $4.3 million in cash from the exercise of stock options during the years ended December 31, 2015, 2014 and 2013, respectively. The excess tax benefit realized for the tax deductions from the exercise of options of the share-based payment arrangements was approximately $3.2 million for the year ended December 31, 2015, $5.3 million for the year ended December 31, 2014, and zero for the year ended December 31, 2013. This tax benefit also decreased cash provided by operating activities, and increased cash provided by financing activities by the same amount for all years presented. The fair value of each option grant is estimated on the date of grant using the Black-Scholes option valuation model. Listed below are the weighted average assumptions used for the fair value computation: Year Ended December 31, 2015 2014 2013 Dividend yield (1) 0.80 % 1.06 % 1.54 % Expected volatility (2) 25.88 % 28.01 % 24.92 % Risk-free interest rate (3) 0.98 % 0.82 % 0.34 % Expected terms (4) 2.74 2.74 2.74 Weighted average fair value of options granted $ 5.00 $ 3.96 $ 2.25 (1) Dividend yield – the dividend yield is based on our historical experience and future expectation of dividend payouts. (2) Expected volatility – we analyzed the volatility of our stock using historical data. (3) Risk-free interest rate – the risk-free interest rate assumption is based on U.S. Treasury securities at a constant maturity with a maturity period that most closely resembles the expected term of the stock option award. (4) Expected term – the expected term of employee stock options represents the weighted-average period the stock options are expected to remain outstanding and has been determined based on an analysis of historical exercise behavior. As of December 31, 2015, there was approximately $3.1 million of unrecognized compensation cost related to stock option compensation awards. That cost is expected to be recognized over a weighted-average period of 1.9 years, and a total period of 3.4 years. A summary of the award activity for the years ended December 31, 2015, 2014, and 2013 is presented below: 2015 2014 2013 Options Weighted Average Exercise Price Options Weighted Average Exercise Price Options Weighted Average Exercise Price Outstanding at beginning of year 2,142,971 $ 17.80 3,374,846 $ 16.26 3,424,806 $ 15.99 Granted 590,141 29.81 399,550 22.74 429,800 15.62 Exercised (594,673 ) 16.65 (1,551,400 ) 15.73 (345,302 ) 12.60 Forfeited and Expired (129,567 ) 21.76 (80,025 ) 17.90 (134,458 ) 16.78 Outstanding at end of year 2,008,872 21.41 2,142,971 17.80 3,374,846 16.26 Vested and exercisable at end of year 989,396 17.45 1,383,888 16.86 2,828,365 16.27 Weighted average fair value of options granted during the period 5.00 3.96 2.25 As of December 31, 2015, the number of options that were currently vested and expected to become vested was 1,926,872. These options have a weighted-average exercise price of $21.12, a weighted-average contractual remaining term of 2.9 years, and an aggregate intrinsic value of $8.8 million. The following table summarizes information about stock options to purchase the Company's common stock at December 31, 2015: Range of Exercise Prices Shares Outstanding Weighted Avg. Contractual Years Remaining Weighted Avg. Exercise Price Per Share Number Vested and Exercisable Weighted Avg. Exercise Price Per Share for Vested and Exercisable $12.63 - 14.73 2,900 3.08 $ 13.34 1,600 $ 13.34 $14.74 - 16.83 440,031 2.57 $ 15.25 276,231 $ 15.06 $16.84 - 18.94 693,697 1.88 $ 18.05 649,297 $ 18.00 $18.95 - 33.27 872,244 3.96 $ 27.21 62,268 $ 22.46 Overall Total 2,008,872 2.94 $ 21.41 989,396 $ 17.45 The total intrinsic value of options exercised during the twelve-month period was $8.3 million, $17.8 million, and $1.5 million in 2015, 2014, and 2013, respectively. Based on the market price as of December 31, 2015, the intrinsic value of options outstanding as of December 31, 2015, was approximately $8.8 million, and the intrinsic value of options exercisable for the same period was approximately $6.7 million. The weighted average remaining contractual life as of December 31, 2015, for vested and exercisable options is 2 years. Since 2009, the Company has issued restricted stock units (“RSUs”) to its employees. The Company 's RSU program consists of service based awards that vest gradually over a period ranging from 5 to 13 years. Stock compensation expense for these RSUs is being amortized using the straight-line method over the requisite service period. As of December 31, 2015, the Company had approximately $10.6 million of unrecognized compensation expense related to restricted stock awards, which will be recognized over a weighted average period of 3.6 years, and a total period of 7.1 years. RSUs not yet vested are entitled to accumulate quarterly cash dividends that are paid to shareholders holding outstanding shares of the Company 's common stock. Accrued dividends are paid to recipients as the RSUs vest. Accrued dividends are forfeited if RSUs are canceled or terminated. Dividends paid under the RSU program are charged to retained earnings. The following tables summarize the Company's restricted stock award activity for the fiscal years ended December 31, 2015, 2014, and 2013: 2015 2014 2013 Number of Restricted Stock Awards Weighted Average Grant Date Fair Value Number of Restricted Stock Awards Weighted Average Grant Date Fair Value Number of Restricted Stock Awards Weighted Average Grant Date Fair Value Unvested at January 1 Unvested at January1, 1,073,546 $ 16.22 1,213,698 $ 16.04 1,210,532 $ 16.04 Granted 13,950 $ 29.11 17,017 $ 27.63 183,111 $ 15.95 Vested (188,253 ) $ 16.03 (128,659 ) $ 16.07 (130,265 ) $ 16.01 Forfeited and Expired (20,070 ) $ 16.64 (28,510 ) $ 16.23 (49,680 ) $ 15.75 Outstanding (unvested) at end of year 879,173 $ 16.45 1,073,546 $ 16.22 1,213,698 $ 16.04 In 2015 and 2014, the Company issued performance restricted stock units (“PRSUs”) to selected key employees that may be earned based on revenue growth and return on assets, and may then be modified based on our total shareholder return, as defined, over the three-year period. The primary award adjustment may range from 0 percent to 150 percent of the initial grant, based upon performance achieved. The primary award modifier, which would multiply the adjusted primary award by 75 percent to 125 percent, is measured by determining the percentile rank of the total shareholder return of Knight common stock in relation to the total shareholder return of a peer group for the three-year period. The final award will be based on performance achieved in accordance with the scale set forth in the plan agreement. Performance restricted stock units do not earn dividend equivalents. The fair value of each PRSU grant is estimated on the date of grant using the Monte Carlo Simulation valuation model. Listed below are the weighted average assumptions used for the fair value computation: Twelve Months Ended December 31, 2015 2014 Dividend yield (1) 0.80 % 1.06 % Expected volatility (2) 23.18 % 26.11 % Average peer volatility (2) 30.70 % 36.01 % Average peer correlation coefficient (3) 0.49 0.5796 Risk-free interest rate (4) 0.78 % 0.66 % Expected term (5) 2.63 2.80 Weighted-average fair value of PRSUs granted $ 29.30 $ 23.85 (1) The dividend yield, used to project stock price to the end of the performance period, is based on our historical experience and future expectation of dividend payouts. Total shareholder return is determined assuming that dividends are reinvested in the issuing entity over the performance period, which is mathematically equivalent to utilizing a 0% dividend yield. (2) We (or peer company) estimated volatility using our (or their) historical share price performance over the remaining performance period as of the grant date. (3) The correlation coefficients are used to model the way in which each entity tends to move in relation to each other; the correlation assumptions were developed using the same stock price data as the volatility assumptions. (4) The risk-free interest rate assumption is based on U.S. Treasury securities at a constant maturity with a maturity period that most closely resembles the expected term of the performance award. (5) Since the Monte Carlo simulation valuation is an open form model that uses an expected life commensurate with the performance period, the expected life of the PRSUs was assumed to be the period from the grant date to the end of the performance period. During 2015, 165,720 PRSU’s were granted and during 2014, 181,112 PRSU’s were granted. The performance measurement period for the PRSUs granted in 2015 is April 1, 2015 to December 31, 2017, and the performance measurement period for the PRSUs granted in 2014 is January 1, 2014 to December 31, 2016. These awards will vest thirteen months following the expiration of the performance measurement period. A summary of the award activity for the years ended December 31, 2015, 2014, and 2013 is presented below: 2015 2014 Number of Performance Restricted Stock Unit Awards Weighted Average Grant Date Fair Value Number of Performance Restricted Stock Unit Awards Weighted Average Grant Date Fair Value Unvested as of January 1 181,112 $ 23.85 181,112 $ 23.85 Granted 165,720 29.30 - - Vested - - - - Cancelled (5,050 ) 26.20 - - Unvested as of December 31 341,782 26.46 181,112 $ 23.85 Our policy is to recognize compensation cost on a straight-line basis over the requisite service period. As of December 31, 2015, there was $7.4 million of unrecognized compensation cost related to performance awards. That cost is expected to be recognized over a weighted-average period of 2.7 years and total period of 3.1 years. b. 401(k) Profit Sharing Plan The Company has a 401(k) profit sharing plan (the "Plan") for all employees who are 18 years of age or older and have completed six months of service with the Company. The Plan provides for a mandatory matching contribution equal to the amount of the employee's salary deduction not to exceed $1,150 annually per employee; this limit was increased in 2015 from 50% of the employee’s salary deduction not to exceed $1,000 in 2014. The limit of the mandatory matching contribution for 2016 has been increased to the amount of employee’s salary deductions not to exceed $1,400. The Plan also provides for a discretionary matching contribution. In 2015, 2014, and 2013, there were no discretionary contributions. Employees' rights to employer contributions vest equally over five years from their date of employment. The Company's mandatory matching contribution was approximately $795,000, $451,000, and $326,000 in 2015, 2014, and 2013, respectively.

Note 9 - Company Share Repurcha

Note 9 - Company Share Repurchase Program	12 Months Ended
	Dec. 31, 2015
Notes to Financial Statements
Treasury Stock [Text Block]	9. Company Share Repurchase Program In May 2011, the Company's Board of Directors unanimously authorized the repurchase of 10.0 million shares of the Company's common stock. The repurchase authorization is intended to afford the Company flexibility to acquire shares opportunistically in future periods and does not indicate an intention to repurchase any particular number of shares within a definite timeframe. Any repurchases would be affected based upon share price and market conditions. The Company repurchased 1.6 million shares under the share repurchase program during the year ended December 31, 2015, and no shares were repurchased during 2014, and 2013. As of December 31, 2015, there were 5.8 million shares remaining for future purchases under the repurchase program. The repurchase authorization will remain in effect until the share limit is reached or the program is terminated.

Note 10 - Segment Information

Note 10 - Segment Information	12 Months Ended
	Dec. 31, 2015
Notes to Financial Statements
Segment Reporting Disclosure [Text Block]	10. Segment Information The Company has two operating segments: (i) the Trucking segment comprised of three operating units (Dry Van, Refrigerated, and Drayage), and (ii) the Logistics segment comprised of two operating units (Brokerage and Intermodal). The Company also provides logistics, freight management and other non-trucking services through its Logistics businesses. Through its Trucking and Logistics segment capabilities, the Company is able to transport, or can arrange for the transportation of, general commodities for customers throughout the United States and parts of Canada and Mexico. The Company, in determining its reportable operating segments, focuses on financial information such as operating revenues and expenses, operating income, operating ratios, and other key operating statistics common in the industry. The chief operating decision makers also use this information to evaluate segment performance and allocate resources to the Company's operations. The Company's operating segments provide transportation and related services for one another. Such services are billed at cost, and no profit is earned. Such intersegment revenues and expenses are eliminated in the Company's consolidated results. The following table sets forth revenue and operating income between the Trucking and Logistics segments for the years ended December 31, 2015, 2014, and 2013. 2015 2014 2013 $ % $ % $ % Revenues: Trucking Segment $ 952,098 80.5 % $ 892,124 80.9 % $ 822,188 84.8 % Logistics Segment 249,365 21.1 214,378 19.4 151,194 15.6 Subtotal 1,201,463 1,106,502 973,382 Intersegment Eliminations Trucking (163 ) 0.0 (65 ) 0.0 (120 ) 0.0 Intersegment Eliminations Logistics (18,336 ) (1.6 ) (4,105 ) (0.3 ) (4,025 ) (0.4 ) Total $ 1,182,964 100 % $ 1,102,332 100 % $ 969,237 100 % Operating Income: Trucking Segment $ 162,143 91.1 % $ 147,424 90.6 % $ 106,167 93.2 % Logistics Segment 15,857 8.9 15,298 9.4 7,742 6.8 Total $ 178,000 100 % $ 162,722 100 % $ 113,909 100 % Trucking Segment Information The Trucking segment operates large, modern, company-owned tractor fleets and use independent contractors to provide various transportation solutions, including multiple stop pick-ups and deliveries, dedicated equipment and personnel, on-time expedited pick-ups and deliveries, specialized driver training, and other truckload services. Revenues are generally set at a predetermined rate per mile or per load for the Trucking services. In addition, revenue streams are also generated by charging for tractor and trailer detention, loading and unloading activities, dedicated services, and other specialized services, as well as through the collection of fuel surcharges to mitigate the impact of increases in the cost of fuel. The primary measurement the Company uses to evaluate the profitability of the Trucking segment is operating ratio, measured both on a GAAP basis (operating expenses expressed as a percentage of revenue) and non-GAAP basis used by many in the Company's industry (operating expenses, net of Trucking fuel surcharge revenue, expressed as a percentage of Trucking revenue, excluding Trucking fuel surcharge revenue). The Company believes the second method allows them to more effectively compare periods while excluding the potentially volatile effect of changes in fuel prices. The tables below compare operating ratio using both methods. The following table sets forth the Trucking segment operating ratio on a GAAP basis. GAAP Presentation: 2015 2014 2013 Trucking (amounts in thousands) $ % $ % $ % Revenue $ 952,098 $ 892,124 $ 822,188 Operating expenses 789,955 83.0 744,700 83.5 716,021 87.1 Operating income $ 162,143 $ 147,424 $ 106,167 The following table sets forth the Trucking segment operating ratio as if fuel surcharges are excluded from total revenue and instead reported as a reduction of operation expenses, excluding intersegment activity. Non-GAAP Presentation (1) 2015 2014 2013 Trucking (amounts in thousands) $ % $ % $ % Revenue $ 952,098 $ 892,124 $ 822,188 Less: Trucking fuel surcharge revenue (121,225 ) (176,347 ) (177,386 ) Less: Intersegment transactions (163 ) (65 ) (120 ) Revenue, net of fuel surcharge and intersegment transactions 830,710 715,712 644,682 Operating expenses 789,955 744,700 716,021 Less: Trucking fuel surcharge revenue (121,225 ) (176,347 ) (177,386 ) Less: Intersegment transactions (163 ) (65 ) (120 ) Operating expenses, net of fuel surcharge and intersegment transactions 668,567 80.5 568,288 79.4 538,515 83.5 Operating income $ 162,143 $ 147,424 $ 106,167 (1) These items represent non-GAAP financial measures and are not substitutes for, and should be considered in addition to, the GAAP financial measures presented in the previous table. The Company's Trucking segment requires substantial capital expenditures for purchases of new revenue equipment. Total depreciation and amortization expense for the Trucking Segment was approximately $107.0 million, $88.2 million, and $81.0 million in 2015, 2014, and 2013, respectively. Logistics Segment Information Logistics revenue is generated primarily by the Brokerage and Intermodal operating units, which charge a predetermined rate per mile or per load for arranging freight transportation for its customers. The Company also provides logistics, freight management and other non-trucking services through its Logistics business. Additional revenue is generated by offering specialized logistics solutions (including, but not limited to, origin management, surge volumes, disaster relief, special projects, and other logistics needs). Logistics revenue is mainly affected by the rates the Company is able to negotiate with clients, the freight volumes that are shipped through third-party capacity providers and the Company's ability to secure qualified third-party capacity providers to transport customer freight. This segment has seen continued growth in the number of shipments serviced by the Brokerage and Intermodal operating units, and contributed to the improved productivity and revenue realized in 2015. The following table sets forth the Logistics segment revenue, other operating expenses, and operating income. 2015 2014 2013 Logistics (amounts in thousands) $ % $ % $ % Revenue $ 249,365 $ 214,378 $ 151,194 Other operating expense 233,508 93.6 199,080 92.9 143,452 94.9 Operating income $ 15,857 $ 15,298 $ 7,742 The following table sets forth the Logistics revenue, operating expenses, and operating income, excluding intersegment transactions. 2015 2014 2013 Logistics (amounts in thousands) $ % $ % $ % Revenue $ 249,365 $ 214,378 $ 151,194 Less: Intersegment transactions (18,336 ) (4,105 ) (4,025 ) Revenue excluding intersegment transactions 231,029 210,273 147,169 Operating expenses 233,508 199,080 143,452 Less: Intersegment transactions (18,336 ) (4,105 ) (4,025 ) Operating expenses excluding intersegment transactions 215,172 93.1 194,975 92.7 139,427 94.7 Operating income $ 15,857 $ 15,298 $ 7,742 The Company primarily measures the Logistics segment's profitability by reviewing the gross margin percentage (revenue, less purchased transportation expense, expressed as a percentage of revenue) and the operating income percentage. The gross margin percentage can be affected by customer rates and the costs of securing third-party capacity providers. The Company's third-party capacity providers are generally not subject to long-term or predetermined contracted rates, and the operating results could be affected if the availability of third-party capacity providers or the rates for such providers change in the future. The following table lists the gross margin percentage for the Company's Brokerage and Intermodal businesses. 2015 2014 2013 Combined Brokerage and Intermodal gross margin percent (1) 16.4 % 15.0 % 12.5 % (1) Gross margin percentage is based on revenue net of intersegment elimination. The Company's Logistics segment does not require significant capital expenditures and is not asset-intensive like the Trucking segment. Total Logistics segment depreciation and amortization expense is primarily attributed to equipment leased to third parties, which totaled to approximately $4.0 million, $4.7 million, and $5.1 million in 2015, 2014, and 2013, respectively. No segmental asset information is provided as the Company does not prepare balance sheets by segment, and the chief operating decision makers do not review segment assets to make operating decisions.

Note 11 - Acquisition of Barr-N

Note 11 - Acquisition of Barr-Nunn Transportation, Inc.	12 Months Ended
	Dec. 31, 2015
Notes to Financial Statements
Business Combination Disclosure [Text Block]	11. Acquisition of Barr-Nunn Transportation, Inc. On October 1, 2014, the Company entered into a Stock Purchase Agreement for the purchase of 100% of the outstanding stock of Barr-Nunn Transportation, Inc., and certain of its affiliates (“Barr-Nunn”). Barr-Nunn is a transportation services carrier headquartered near Des Moines, Iowa, offering dry van truckload transportation and logistics services, with its primary operating territory in the eastern United States. Barr-Nunn had an enterprise value at closing of approximately $112.4 million (before the potential earn-out payment discussed below). At closing, the Company paid approximately $111.2 million of total consideration for the stock and certain real estate, which was paid in cash and funded through borrowings under the Company’s line of credit on the date of the transaction. The purchase price was adjusted in December 2014 pursuant to a customary working capital adjustment, which produced a credit of approximately $0.7 million to the Company, resulting in total consideration paid of $110.5 million. The Stock Purchase Agreement included an election under the Internal Revenue Code Section 338(h)(10). Accordingly, the book and tax basis of the acquired assets and liabilities are the same as of the purchase date. The Stock Purchase Agreement contains customary representations, warranties, covenants, and indemnification provisions. At closing, $8.0 million of the purchase price was placed in escrow to secure the Sellers' indemnification obligations. The results of the acquired business have been included in the consolidated financial statements since the date of acquisition and represented 12.0% of consolidated total assets as of December 31, 2014, 3.0% of total revenue for 2014, and 3.8% of net income for 2014. The Company recorded approximately $429,000 of acquisition-related expenses, which are included within “Miscellaneous operating expenses” in the consolidated statement of income for the year ended December 31, 2014. The following unaudited pro forma consolidated results of operations for the years ended December 31, 2014, and 2013, assume that the acquisition of Barr-Nunn occurred as of January 1, 2013. (Unaudited) Years ended December 31, 2014 December 31, 2013 (in thousands) Total revenue $ 1,192,745 $ 1,087,790 Net income 109,787 78,274 These pro forma amounts do not purport to be indicative of the results that would have actually been obtained if the acquisition had occurred at the beginning of the periods presented or that may be obtained in the future. The allocation of the purchase price is provided in the tables below. The final purchase price allocation was subject to a post-closing working capital adjustment, and subject to earn-out amounts achieved, and other adjustments. The goodwill recognized represents expected synergies from combining the operations of the Company with Barr-Nunn, including enhanced service offerings and sharing best practices in terms of driver recruiting and retention, as well as other intangible assets that did not meet the criteria for separate recognition. All tax goodwill recognized in the transaction is deductible for tax purposes over 15 years, and no deferred taxes were recorded. ALLOCATION OF PURCHASE PRICE (in thousands) Total fair value of consideration transferred $ 110,517 Allocated to: Historical book value of Barr-Nunn’s assets and liabilities (excluding cash) l71,656 Adjustments to recognize assets and liabilities at acquisition-date fair value: Property, and equipment 3,349 Liabilities (5,023) Fair value of tangible net assets acquired 69,982 Identifiable intangibles at acquisition-date fair value 3,700 Excess of consideration transferred over the net amount of assets and liabilities recognized, including $3.5 million attributable to the fair value of a potential earn-out obligation (goodwill) $ 36,835 Excess of consideration transferred over the net amount of assets and liabilities recognized (goodwill) was subject to final purchase price adjustment related to earn-out amounts achieved (if any) and other adjustments. The assets and liabilities associated with Barr-Nunn were recorded at their fair values as of the acquisition date and the amounts are as follows: (in thousands) Trade receivables $ 11,380 Other current assets 2,316 Property and equipment 68,444 Goodwill 36,835 Intangible assets 3,700 Total assets 122,675 Accounts payable (3,311 ) Accrued liabilities (5,638 ) Claims accruals (3,209 ) Total consideration transferred $ 110,517 TOTAL PURCHASE PRICE CONSIDERATION (in thousands) Cash paid pursuant to Stock Purchase and Real Estate Agreements $ 110,517 The Stock Purchase Agreement also provides for a potential one-time earn-out payment of up to $3.5 million, contingent upon achievement of an operating income target for Barr-Nunn and retention of key personnel for the four fiscal quarters ending September 30, 2015. This contingent liability was estimated as of the date of the transaction and was included in the adjustments to liabilities at the transaction-date fair value recorded. The fair value of the contingent liability was subject to change based on actual results of Barr-Nunn over the four fiscal quarters ending September 30, 2015. All contingencies were satisfied and the earn-out was paid in full in October 2015.

Note 12 - Quarterly Financial D

Note 12 - Quarterly Financial Data (unaudited)	12 Months Ended
	Dec. 31, 2015
Notes to Financial Statements
Quarterly Financial Information [Text Block]	12. Quarterly Financial Data (unaudited) The following table sets forth certain unaudited information about the Company's revenue and results of operations on a quarterly basis for 2015 and 2014 (amount in thousands, except per share data): 2015 Mar 31 June 30 Sept 30 Dec 31 Revenue, before fuel surcharge $ 257,214 $ 268,623 $ 269,930 $ 265,972 Income from operations $ 46,304 $ 41,619 $ 46,426 $ 43,652 Net income attributable to Knight $ 29,563 $ 27,638 $ 30,283 $ 29,235 Earnings per common share: Basic $ 0.36 $ 0.34 $ 0.37 $ 0.36 Diluted $ 0.36 $ 0.33 $ 0.37 $ 0.36 2014 Mar 31 June 30 Sept 30 Dec 31 Revenue, before fuel surcharge $ 205,596 $ 218,908 $ 227,829 $ 273,653 Income from operations $ 31,250 $ 38,899 $ 39,791 $ 52,782 Net income attributable to Knight $ 19,064 $ 25,761 $ 25,100 $ 32,938 Earnings per common share: Basic $ 0.24 $ 0.32 $ 0.31 $ 0.40 Diluted $ 0.23 $ 0.31 $ 0.31 $ 0.40 The Company acquired 100% of the outstanding stock of Barr-Nunn on October 1, 2014 and therefore the operating results of the Company includes the operating results of Barr-Nunn for the periods from October 1, 2014 to December 31, 2015.

Note 13 - Subsequent Events

Note 13 - Subsequent Events	12 Months Ended
	Dec. 31, 2015
Notes to Financial Statements
Subsequent Events [Text Block]	13. Subsequent Events The Company has evaluated events occurring subsequent to December 31, 2015, through the filing date of this Annual Report on Form 10-K for disclosure. No events occurred requiring disclosure.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts and Reserves	12 Months Ended
	Dec. 31, 2015
Notes to Financial Statements
Schedule of Valuation and Qualifying Accounts Disclosure [Text Block]	Valuation and Qualifying Accounts and Reserves For the Years Ended December 31, 2015, 2014 and 2013 (in thousands) Balance at Beginning of Period Provision for Bad Debt Other Accounts (1) Bad Debt Write-offs Balance at End of Period Allowance for doubtful trade receivables: Year ended December 31, 2015 $ 3,355 $ 1,333 - $ (1,582 ) $ 3,106 Year ended December 31, 2014 $ 2,409 $ 1,309 $ 146 $ (509 ) $ 3,355 Year ended December 31, 2013 $ 1,917 $ 952 - $ (460 ) $ 2,409 Balance at Beginning of Period Provision for Credit Losses Other Accounts Bad Debt Write-offs Balance at End of Period Allowance for doubtful notes receivable: Year ended December 31, 2015 $ 351 $ 26 - $ (104 ) $ 273 Year ended December 31, 2014 $ 312 $ 42 - $ (3 ) $ 351 Year ended December 31, 2013 $ 291 $ 55 - $ (34 ) $ 312 (1) Addition to allowance for doubtful accounts following acquisition of Barr-Nunn.

Significant Accounting Policies

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Consolidation, Policy [Policy Text Block]	Principles of Consolidation -
Use of Estimates, Policy [Policy Text Block]	Use of Estimates -
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents
Finance, Loans and Leases Receivable, Policy [Policy Text Block]	Notes Receivable The notes receivable balances are classified separately between current and long-term notes in the consolidated balance sheets. The current and long-term balances of our notes receivables as of December 31, 2015 and 2014 are as follows: 2015 2014 (in thousands) Notes receivable from independent contractors $ 794 $ 1,554 Notes receivable from third parties 3,546 3,882 Gross notes receivable 4,340 5,436 Allowance for doubtful notes receivable (273 ) (351 ) Total notes receivable, net of allowance $ 4,067 $ 5,085 Current portion, net of allowance 648 1,020 Long-term portion $ 3,419 $ 4,065
Disclosure of Long Lived Assets Held for Sale [Policy Text Block]	Assets Held for Sale
Inventory, Policy [Policy Text Block]	Other Current Assets
Property, Plant and Equipment, Policy [Policy Text Block]	Property and Equipment - Years Land improvements 5 - 10 Buildings and improvements 10 - 30 Furniture and fixtures 3 - 10 Shop and service equipment 2 - 10 Revenue equipment 5 - 10 Leasehold improvements 1 - 5 To ensure that our facilities remain modern and efficient, we periodically have facility upgrades, or new construction, in process at our various service center locations or corporate headquarters. Until these projects are completed, we consider these to be assets not yet placed in service and they are not depreciated. Once they are placed into service, we depreciate them according to our depreciation policy. At December 31, 2015 and December 31, 2014, we had approximately $17.5 million and $6.9 million, respectively, of facility construction in process assets included under "Buildings and building improvements” on the accompanying consolidated balance sheets. The Company expenses repairs and maintenance as incurred. For the years ended December 31, 2015, 2014, and 2013, repairs and maintenance expense totaled approximately $33.4 million, $30.9 million, and $30.5 million, respectively. The expense is included in “Operations and maintenance” expense in the accompanying consolidated statements of income. The Company periodically reviews the reasonableness of its estimates regarding useful lives and salvage values for revenue equipment and other long-lived assets based upon, among other things, the Company's experience with similar assets, conditions in the used revenue equipment market, and prevailing industry practice. Tires on revenue equipment purchased are capitalized as a part of the equipment cost and depreciated over the life of the vehicle. Replacement tires and recapping costs are expensed when placed in service.
Investment, Policy [Policy Text Block]	Other Long-term Assets and Restricted Cash and Investments include 2015 2014 (in thousands) Investment in Transportation Resource Partners (TRP) $ 300 $ 477 Investment in Transportation Resource Partners III (TRP III) 5,752 5,412 Restricted Cash and Investments 3,282 3,264 Available-For-Sale Equity Securities 7,101 26,884 Other 2,497 1,243 $ 18,932 $ 37,280 In 2003, the Company signed a partnership agreement with TRP, a company that makes privately negotiated equity investments. According to the original partnership agreement, the Company committed to invest $5.0 million out of approximately $260.0 million total, for a 1.9% ownership interest. In early 2006, the Company increased the commitment amount to $5.5 million. Contributions to TRP are accounted for using the cost method as the level of influence over the operations of TRP is minor, and no contributions have been made to TRP since 2011. In 2015, the Company recorded gains and received distributions totaling $208,000. In 2014, distributions of $2.1 million were received and a $1.6 million gain was recorded, while in 2013, distributions received and gains recorded were $467,000. The gains are recognized in the year distributions are received. The Company also recorded impairment of $177,000, $1.0 million and $209,000 in 2015, 2014, and 2013, respectively, for other-than-temporary loss on the investments remaining within the TRP portfolio. The Company's ownership interest in TRP is approximately 2.2%, with a carrying value of $300,000 and $477,000 at December 31, 2015 and 2014, respectively. In the fourth quarter of 2008, the Company committed to invest $15.0 million in a new partnership managed and operated by the managers and principals of TRP. The new partnership, TRP III, focuses on the same investment opportunities as TRP. Since its inception, the Company has contributed approximately $11.0 million to TRP III.In June 2015, based on an analysis of expected future fund activity, TRP III released investors from a portion of their outstanding commitment. The Company’s share of the commitment release was $2.1 million leaving an outstanding commitment of $1.9 million as of December 31, 2015. The investment in TRP III is accounted for using the equity method. The Company has recorded income of approximately $422,000, $6.1 million, and $669,000 for its investment in TRP III for years ended December 31, 2015, 2014, and 2013, respectively. In 2015, the Company received distributions totaling $152,000 from TRP III for the sale of TRP III portfolio companies. At December 31, 2015, the investment balance in TRP III was $5.8 million, compared to $5.4 million at December 31, 2014. The Company's ownership interest was approximately 6.1% as at December 31, 2015. In the third quarter of 2015, the Company committed to invest in a new partnership, TRP Capital Partners, LP (TRP IV”). The new partnership is managed and operated by the managers and principals of TRP and TRP III, and is focused on similar investment opportunities. The Company committed to contribute a total of $4.9 million to the new partnership, and has contributed $41,000 as of December 31, 2015. Since the year-end, the Company has committed to invest in another TRP partnership, TRP CoInvest Partners (NTI) I, LP. This new partnership is also operated and managed by the managers and principals of TRP and TRP III, and is focused on similar investment opportunities. The Company committed to contribute a total of $10.0 million to the new partnership, and fulfilled its commitment in February 2016.
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]	Restricted Cash and Investments – In accordance with the provisions of ASC 210, Balance Sheet Investments – Debt and Equity Securities
Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]	Impairment of Long-Lived Assets – Property, Plant and Equipment Long-lived Assets
Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]	Goodwill & Intangibles, net Goodwill In 2015, the Company changed the date of the annual impairment testing to June 30 from September 30. This change did not result in the delay, acceleration or avoidance of an impairment charge. The Company believes this change in accounting principle is preferable because it better aligns with the Company’s annual strategic and planning process and alleviates administrative burden during the year-end reporting period. This change to the annual goodwill impairment testing was applied prospectively and had no effect on these consolidated financial statements. This change was not applied retrospectively as it is impractical to do so because retrospective application would have required the application of significant estimates and assumptions without use of hindsight. The Company completed this annual test as of June 30, 2015, and September 30, 2014, and no adjustment for impairment was determined to be necessary. In conjunction with the acquisition of Roads West in 2006, the basis of goodwill for tax purposes was determined to be in excess of the book basis of goodwill. Under this circumstance, ASC 740, Income Taxes Business Combination The changes in the carrying amounts of goodwill were as follows: 2015 2014 (in thousands) Goodwill at beginning of period $ 47,067 $ 10,257 Acquisition - 36,835 Amortization relating to deferred tax assets (17 ) (25 ) Goodwill at end of period $ 47,050 $ 47,067 Identifiable intangible assets subject to amortization relate to customer relations and trade names acquired through the 2014 acquisition of Barr-Nunn Transportation, Inc. and certain of its affiliates (“Barr-Nunn”). The intangible assets acquired were recorded at fair value at the date of acquisition. Intangible asset balances were as follows: 2015 2014 (in thousands) Gross carrying amount $ 3,700 $ 3,700 Accumulated amortization (625 ) (125 ) Intangible assets, net $ 3,075 $ 3,575 These intangible assets are being amortized over a weighted average amortization period of 7.6 years. Amortization expense associated with these intangible assets was $0.5 million, and $0.1 million for the year ended December 31, 2015, and December 31, 2014, respectively, and was included in depreciation and amortization expense in the accompanying consolidated statements of income. Future amortization expense for intangible assets is estimated at $0.5 million for 2016 through 2019, and $0.4 million in 2020.
Claims Accrual [Policy Text Block]	Claims Accrual -
Revenue Recognition, Policy [Policy Text Block]	Revenue Recognition - In accordance with ASC 605-45, Revenue Recognition – Principal Agent Consideration
Receivables, Trade and Other Accounts Receivable, Allowance for Doubtful Accounts, Policy [Policy Text Block]	Allowance for Doubtful Accounts Allowance for Doubtful Notes Receivable
Income Tax, Policy [Policy Text Block]	Income Taxes The Company records a valuation allowance for deferred tax assets to the extent it believes these assets are not more likely than not to be realized. In making such determinations, the Company considers all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax planning strategies, and recent financial operations. A valuation allowance for deferred tax assets has not been deemed necessary due to the Company's profitable operations. The Company recognizes a tax benefit from an uncertain tax position when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits.
Fair Value of Financial Instruments, Policy [Policy Text Block]	Financial Instruments The Company's financial instruments include cash equivalents, investments held for trading, available-for-sale securities, trade receivables, notes receivable, accounts payable and long-term debt. Due to the short-term nature of cash equivalents, trade receivables, and accounts payable, the fair value of these instruments approximates their recorded value. Available-for-sale and trading securities consist of marketable equity and debt securities stated at fair value. Due to the variable interest rate, the carrying value of long-term debt approximates fair value.
Concentration Risk, Credit Risk, Policy [Policy Text Block]	Concentration of Credit Risk -
Earnings Per Share, Policy [Policy Text Block]	Earnings Per Share 2015 2014 2013 Net Income ( numerator ) Shares ( denominator ) Per Share Amount Net Income ( numerator ) Shares ( denominator ) Per Share Amount Net Income ( numerator ) Shares ( denominator ) Per Share Amount Basic EPS $ 116,718 81,491 $ 1.43 $ 102,862 80,947 $ 1.27 $ 69,282 79,994 $ 0.87 Effect of stock options & restricted stock - 976 - 1,095 - 336 Diluted EPS $ 116,718 82,467 $ 1.42 $ 102,862 82,042 $ 1.25 $ 69,282 80,330 $ 0.86 Certain shares of options, restricted stock units, and performance restricted stock units (“equity awards”) were excluded from the computation of diluted earnings per share because the equity award’s exercise prices were greater than the average market price of the common shares and the sum total of assumed proceeds resulted in fewer shares repurchased than the weighted equity awards outstanding hypothetically exercised per the treasury method. A summary of those shares for the years ended December 31, 2015, 2014, and 2013, respectively, is as follows: 2015 2014 2013 Number of anti-dilutive shares 387,969 232,803 1,917,020
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). This update seeks to increases the transparency and comparability among entities by requiring public entities to recognize lease assets and lease liabilities on the balance sheet and disclose key information about leasing arrangements. To satisfy the standard’s objective, a lessee will recognize a right-of-use asset representing its right to use the underlying asset for the lease term and a lease liability for the obligation to make lease payments. Both the right-of-use asset and lease liability will initially be measured at the present value of the lease payments, with subsequent measurement dependent on the classification of the lease as either a finance or an operating lease. For leases with a term of 12 months or less, a lessee is permitted to make an accounting policy election by class of underlying asset not to recognize lease assets and lease liabilities. If a lessee makes this election, it should recognize lease expense for such leases generally on a straight-line basis over the lease term. Accounting by lessors will remain mostly unchanged from current U.S. GAAP. In transition, lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The modified retrospective approach includes a number of optional practical expedients that companies may elect to apply. These practical expedients relate to the identification and classification of leases that commenced before the effective date, initial direct costs for leases that commenced before the effective date, and the ability to use hindsight in evaluating lessee options to extend or terminate a lease or to purchase the underlying asset. The transition guidance also provides specific guidance for sale and leaseback transactions, build-to-suit leases, leveraged leases, and amounts previously recognized in accordance with the business combinations guidance for leases. The new standard is effective for public companies for annual periods beginning after December 15, 2018, and interim periods within those years, with early adoption permitted. The Company is currently evaluating the effect that adopting this standard will have on the Company’s consolidated financial statements. In January 2016, the FASB issued ASU 2016-01, Financial Instruments–Overall (Subtopic 825-10).This update was issued to enhance the reporting model for financial instruments regarding certain aspects of recognition, measurement, presentation, and disclosure. The update (i) requires equity investments (except those accounted for under the equity method or that are consolidated) to be measured at fair value with changes in fair value recognized in net income; (ii) simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment; (iii) eliminates the requirement for an entity to disclose the methods and significant assumptions used to estimate the fair value of financial instruments measured at amortized cost; (iv) requires an entity to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes; and (v) requires separate presentation of financial assets and financial liabilities by measurement category and form of financial asset on the balance sheet or in the accompanying notes to the financial statements. These provisions are effective for annual reporting periods beginning after December 15, 2017, and interim periods within those annual periods. The standard is to be applied using a cumulative-effect adjustment to the balance sheet as of the beginning of the year of adoption. The Company is currently evaluating the effect that adopting this standard will have on the Company’s consolidated financial statements. In November 2015, the FASB issued ASU 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes. In June 2014, the FASB issued ASU 2014-12, Stock Compensation - Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers

Note 1 - Organization and Sum24

Note 1 - Organization and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Notes Tables
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]	2015 2014 (in thousands) Notes receivable from independent contractors $ 794 $ 1,554 Notes receivable from third parties 3,546 3,882 Gross notes receivable 4,340 5,436 Allowance for doubtful notes receivable (273 ) (351 ) Total notes receivable, net of allowance $ 4,067 $ 5,085 Current portion, net of allowance 648 1,020 Long-term portion $ 3,419 $ 4,065
Schedule of Estimated Useful Lives [Table Text Block]	Years Land improvements 5 - 10 Buildings and improvements 10 - 30 Furniture and fixtures 3 - 10 Shop and service equipment 2 - 10 Revenue equipment 5 - 10 Leasehold improvements 1 - 5
Schedule of Other Assets [Table Text Block]	2015 2014 (in thousands) Investment in Transportation Resource Partners (TRP) $ 300 $ 477 Investment in Transportation Resource Partners III (TRP III) 5,752 5,412 Restricted Cash and Investments 3,282 3,264 Available-For-Sale Equity Securities 7,101 26,884 Other 2,497 1,243 $ 18,932 $ 37,280
Schedule of Goodwill [Table Text Block]	2015 2014 (in thousands) Goodwill at beginning of period $ 47,067 $ 10,257 Acquisition - 36,835 Amortization relating to deferred tax assets (17 ) (25 ) Goodwill at end of period $ 47,050 $ 47,067
Finite-lived Intangible Assets Amortization Expense [Table Text Block]	2015 2014 (in thousands) Gross carrying amount $ 3,700 $ 3,700 Accumulated amortization (625 ) (125 ) Intangible assets, net $ 3,075 $ 3,575
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	2015 2014 2013 Net Income ( numerator ) Shares ( denominator ) Per Share Amount Net Income ( numerator ) Shares ( denominator ) Per Share Amount Net Income ( numerator ) Shares ( denominator ) Per Share Amount Basic EPS $ 116,718 81,491 $ 1.43 $ 102,862 80,947 $ 1.27 $ 69,282 79,994 $ 0.87 Effect of stock options & restricted stock - 976 - 1,095 - 336 Diluted EPS $ 116,718 82,467 $ 1.42 $ 102,862 82,042 $ 1.25 $ 69,282 80,330 $ 0.86
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	2015 2014 2013 Number of anti-dilutive shares 387,969 232,803 1,917,020

Note 2 - Fair Value Measureme25

Note 2 - Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2015
Other Income [Member]
Notes Tables
Schedule of Realized Gain (Loss) [Table Text Block]	December 31, 2015 2014 2013 (in thousands) Sales proceeds $ 12,528 $ 6,355 $ 8,782 Cost of securities sold 3,937 3,190 6,857 Realized gain $ 8,591 $ 3,165 $ 1,925 Realized gains, net of taxes $ 5,273 $ 1,932 $ 1,189
Fair Value Measurements, Nonrecurring [Table Text Block]	Level One Level Two Level Three Balance at December 31, 2015 Balance at December 31, 2014 Balance at December 31, 2015 Balance at December 31, 2014 Balance at December 31, 2015 Balance at December 31, 2014 Balance at December 31, 2015 Balance at December 31, 2014 (in thousands) Assets: Available-for-sale Securities: Equity securities - common shares $ 7,101 $ 26,884 $ 7,101 $ 26,884 - - - - Restricted cash and investments: Money market funds $ 1,003 $ 1,027 $ 1,003 $ 1,027 - - - - Trading Securities: Debt securities - municipal securities $ 2,279 $ 2,237 - - $ 2,279 $ 2,237 - -

Note 4 - Income Taxes (Tables)

Note 4 - Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Notes Tables
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	2015 2014 2013 Current income taxes: Federal $ 41,549 $ 42,101 $ 46,445 State 4,966 8,648 5,573 46,515 50,749 52,018 Deferred income taxes: Federal 19,666 12,644 (5,520 ) State 1,866 4,416 182 21,532 17,060 (5,338 ) $ 68,047 $ 67,809 $ 46,680
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	2015 2014 2013 Tax at the statutory rate (35%) $ 65,277 $ 60,141 $ 40,846 State income taxes, net of federal benefit 4,441 8,492 3,804 Nondeductible driver per diem 1,982 1,885 1,807 Other, net (3,653 ) (2,709 ) 223 $ 68,047 $ 67,809 $ 46,680
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	2015 2014 Short-term deferred tax assets (liabilities): Claims accrual - $ 6,322 Investments - (2,066 ) Prepaid expenses deducted for tax purposes - (2,952 ) Other, net - 1,883 Short-term deferred tax assets, net - $ 3,187 Long-term deferred tax liabilities (assets): Property and equipment depreciation $ 185,678 $ 161,209 Claims accrual (10,578 ) (4,482 ) Stock options (3,837 ) (2,847 ) Investments 582 7,807 Prepaid expenses deducted for tax purposes 2,947 - Other, net (627 ) 320 Long-term deferred liabilities, net $ 174,165 $ 162,007

Note 5 - Commitments and Cont27

Note 5 - Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Notes Tables
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	Year Ending December 31, Amount (in thousands) 2016 $ 3,242 2017 3,172 2018 1,684 2019 213 2020 219 2021 36 Total $ 8,566

Note 6 - Claims Accrual (Tables

Note 6 - Claims Accrual (Tables)	12 Months Ended
	Dec. 31, 2015
Notes Tables
Schedule of Accrued Liabilities [Table Text Block]	2015 2014 (in thousands) Auto reserves $ 18,926 $ 18,075 Workers' compensation reserves 8,815 8,728 Employee medical reserves 3,238 3,234 Total reserves $ 30,979 $ 30,037 Current portion $ 19,471 $ 18,532 Long-term portion $ 11,508 $ 11,505
Schedule of Liability for Unpaid Claims and Claims Adjustment Expense [Table Text Block]	2015 2014 (in thousands) Beginning Balance $ 30,037 $ 24,505 Acquisition (1) - 3,209 Provisions recorded 52,031 49,135 Claims paid and direct expenses (51,089 ) (46,812 ) Total reserves $ 30,979 $ 30,037

Note 7 - Shareholders' Equity (

Note 7 - Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2015
Notes Tables
Schedule of Share-based Compensation, Nonemployee Director Stock Award Plan, Activity [Table Text Block]	2015 2014 2013 Annual director fees paid through stock issuance $ 354,168 $ 200,484 $ 167,946 Shares of common stock issued 11,853 8,828 9,885 Dividends paid per common share $ 0.24 $ 0.24 $ 0.24

Note 8 - Stock-Based Compensa30

Note 8 - Stock-Based Compensation and Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2015
Performance Shares [Member]
Notes Tables
Schedule of Share-based Payment Award, Equity Instruments Other than Stock Options, Valuation Assumptions [Table Text Block]	Twelve Months Ended December 31, 2015 2014 Dividend yield (1) 0.80 % 1.06 % Expected volatility (2) 23.18 % 26.11 % Average peer volatility (2) 30.70 % 36.01 % Average peer correlation coefficient (3) 0.49 0.5796 Risk-free interest rate (4) 0.78 % 0.66 % Expected term (5) 2.63 2.80 Weighted-average fair value of PRSUs granted $ 29.30 $ 23.85
Restricted Stock Units (RSUs) [Member]
Notes Tables
Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]	2015 2014 2013 Number of Restricted Stock Awards Weighted Average Grant Date Fair Value Number of Restricted Stock Awards Weighted Average Grant Date Fair Value Number of Restricted Stock Awards Weighted Average Grant Date Fair Value Unvested at January 1 Unvested at January1, 1,073,546 $ 16.22 1,213,698 $ 16.04 1,210,532 $ 16.04 Granted 13,950 $ 29.11 17,017 $ 27.63 183,111 $ 15.95 Vested (188,253 ) $ 16.03 (128,659 ) $ 16.07 (130,265 ) $ 16.01 Forfeited and Expired (20,070 ) $ 16.64 (28,510 ) $ 16.23 (49,680 ) $ 15.75 Outstanding (unvested) at end of year 879,173 $ 16.45 1,073,546 $ 16.22 1,213,698 $ 16.04
Stock Compensation Plan [Member]
Notes Tables
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	Year Ended December 31, 2015 2014 2013 Dividend yield (1) 0.80 % 1.06 % 1.54 % Expected volatility (2) 25.88 % 28.01 % 24.92 % Risk-free interest rate (3) 0.98 % 0.82 % 0.34 % Expected terms (4) 2.74 2.74 2.74 Weighted average fair value of options granted $ 5.00 $ 3.96 $ 2.25
Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]	2015 2014 2013 Options Weighted Average Exercise Price Options Weighted Average Exercise Price Options Weighted Average Exercise Price Outstanding at beginning of year 2,142,971 $ 17.80 3,374,846 $ 16.26 3,424,806 $ 15.99 Granted 590,141 29.81 399,550 22.74 429,800 15.62 Exercised (594,673 ) 16.65 (1,551,400 ) 15.73 (345,302 ) 12.60 Forfeited and Expired (129,567 ) 21.76 (80,025 ) 17.90 (134,458 ) 16.78 Outstanding at end of year 2,008,872 21.41 2,142,971 17.80 3,374,846 16.26 Vested and exercisable at end of year 989,396 17.45 1,383,888 16.86 2,828,365 16.27 Weighted average fair value of options granted during the period 5.00 3.96 2.25
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]	Range of Exercise Prices Shares Outstanding Weighted Avg. Contractual Years Remaining Weighted Avg. Exercise Price Per Share Number Vested and Exercisable Weighted Avg. Exercise Price Per Share for Vested and Exercisable $12.63 - 14.73 2,900 3.08 $ 13.34 1,600 $ 13.34 $14.74 - 16.83 440,031 2.57 $ 15.25 276,231 $ 15.06 $16.84 - 18.94 693,697 1.88 $ 18.05 649,297 $ 18.00 $18.95 - 33.27 872,244 3.96 $ 27.21 62,268 $ 22.46 Overall Total 2,008,872 2.94 $ 21.41 989,396 $ 17.45
Share-based Compensation, Performance Shares Award Unvested Activity [Table Text Block]	2015 2014 Number of Performance Restricted Stock Unit Awards Weighted Average Grant Date Fair Value Number of Performance Restricted Stock Unit Awards Weighted Average Grant Date Fair Value Unvested as of January 1 181,112 $ 23.85 181,112 $ 23.85 Granted 165,720 29.30 - - Vested - - - - Cancelled (5,050 ) 26.20 - - Unvested as of December 31 341,782 26.46 181,112 $ 23.85

Note 10 - Segment Information (

Note 10 - Segment Information (Tables)	12 Months Ended
	Dec. 31, 2015
Brokerage and Intermodal [Member]
Notes Tables
Schedule of Segment Reporting Information, by Segment [Table Text Block]	2015 2014 2013 Combined Brokerage and Intermodal gross margin percent (1) 16.4 % 15.0 % 12.5 %
Logistics Segment [Member]
Notes Tables
Reconciliation of Revenue from Segments to Consolidated [Table Text Block]	2015 2014 2013 Logistics (amounts in thousands) $ % $ % $ % Revenue $ 249,365 $ 214,378 $ 151,194 Other operating expense 233,508 93.6 199,080 92.9 143,452 94.9 Operating income $ 15,857 $ 15,298 $ 7,742 2015 2014 2013 Logistics (amounts in thousands) $ % $ % $ % Revenue $ 249,365 $ 214,378 $ 151,194 Less: Intersegment transactions (18,336 ) (4,105 ) (4,025 ) Revenue excluding intersegment transactions 231,029 210,273 147,169 Operating expenses 233,508 199,080 143,452 Less: Intersegment transactions (18,336 ) (4,105 ) (4,025 ) Operating expenses excluding intersegment transactions 215,172 93.1 194,975 92.7 139,427 94.7 Operating income $ 15,857 $ 15,298 $ 7,742
Trucking Segment [Member]
Notes Tables
Reconciliation of Revenue from Segments to Consolidated [Table Text Block]	GAAP Presentation: 2015 2014 2013 Trucking (amounts in thousands) $ % $ % $ % Revenue $ 952,098 $ 892,124 $ 822,188 Operating expenses 789,955 83.0 744,700 83.5 716,021 87.1 Operating income $ 162,143 $ 147,424 $ 106,167 Non-GAAP Presentation (1) 2015 2014 2013 Trucking (amounts in thousands) $ % $ % $ % Revenue $ 952,098 $ 892,124 $ 822,188 Less: Trucking fuel surcharge revenue (121,225 ) (176,347 ) (177,386 ) Less: Intersegment transactions (163 ) (65 ) (120 ) Revenue, net of fuel surcharge and intersegment transactions 830,710 715,712 644,682 Operating expenses 789,955 744,700 716,021 Less: Trucking fuel surcharge revenue (121,225 ) (176,347 ) (177,386 ) Less: Intersegment transactions (163 ) (65 ) (120 ) Operating expenses, net of fuel surcharge and intersegment transactions 668,567 80.5 568,288 79.4 538,515 83.5 Operating income $ 162,143 $ 147,424 $ 106,167
Reconciliation of Revenue from Segments to Consolidated [Table Text Block]	2015 2014 2013 $ % $ % $ % Revenues: Trucking Segment $ 952,098 80.5 % $ 892,124 80.9 % $ 822,188 84.8 % Logistics Segment 249,365 21.1 214,378 19.4 151,194 15.6 Subtotal 1,201,463 1,106,502 973,382 Intersegment Eliminations Trucking (163 ) 0.0 (65 ) 0.0 (120 ) 0.0 Intersegment Eliminations Logistics (18,336 ) (1.6 ) (4,105 ) (0.3 ) (4,025 ) (0.4 ) Total $ 1,182,964 100 % $ 1,102,332 100 % $ 969,237 100 % Operating Income: Trucking Segment $ 162,143 91.1 % $ 147,424 90.6 % $ 106,167 93.2 % Logistics Segment 15,857 8.9 15,298 9.4 7,742 6.8 Total $ 178,000 100 % $ 162,722 100 % $ 113,909 100 %

Note 11 - Acquisition of Barr32

Note 11 - Acquisition of Barr-Nunn Transportation, Inc. (Tables)	12 Months Ended
	Dec. 31, 2015
Notes Tables
Business Acquisition, Pro Forma Information [Table Text Block]	(Unaudited) Years ended December 31, 2014 December 31, 2013 (in thousands) Total revenue $ 1,192,745 $ 1,087,790 Net income 109,787 78,274
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	ALLOCATION OF PURCHASE PRICE (in thousands) Total fair value of consideration transferred $ 110,517 Allocated to: Historical book value of Barr-Nunn’s assets and liabilities (excluding cash) l71,656 Adjustments to recognize assets and liabilities at acquisition-date fair value: Property, and equipment 3,349 Liabilities (5,023) Fair value of tangible net assets acquired 69,982 Identifiable intangibles at acquisition-date fair value 3,700 Excess of consideration transferred over the net amount of assets and liabilities recognized, including $3.5 million attributable to the fair value of a potential earn-out obligation (goodwill) $ 36,835 (in thousands) Trade receivables $ 11,380 Other current assets 2,316 Property and equipment 68,444 Goodwill 36,835 Intangible assets 3,700 Total assets 122,675 Accounts payable (3,311 ) Accrued liabilities (5,638 ) Claims accruals (3,209 ) Total consideration transferred $ 110,517 TOTAL PURCHASE PRICE CONSIDERATION (in thousands) Cash paid pursuant to Stock Purchase and Real Estate Agreements $ 110,517

Note 12 - Quarterly Financial33

Note 12 - Quarterly Financial Data (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2015
Notes Tables
Schedule of Quarterly Financial Information [Table Text Block]	2015 Mar 31 June 30 Sept 30 Dec 31 Revenue, before fuel surcharge $ 257,214 $ 268,623 $ 269,930 $ 265,972 Income from operations $ 46,304 $ 41,619 $ 46,426 $ 43,652 Net income attributable to Knight $ 29,563 $ 27,638 $ 30,283 $ 29,235 Earnings per common share: Basic $ 0.36 $ 0.34 $ 0.37 $ 0.36 Diluted $ 0.36 $ 0.33 $ 0.37 $ 0.36 2014 Mar 31 June 30 Sept 30 Dec 31 Revenue, before fuel surcharge $ 205,596 $ 218,908 $ 227,829 $ 273,653 Income from operations $ 31,250 $ 38,899 $ 39,791 $ 52,782 Net income attributable to Knight $ 19,064 $ 25,761 $ 25,100 $ 32,938 Earnings per common share: Basic $ 0.24 $ 0.32 $ 0.31 $ 0.40 Diluted $ 0.23 $ 0.31 $ 0.31 $ 0.40

Schedule II - Valuation and Q34

Schedule II - Valuation and Qualifying Accounts and Reserves (Tables)	12 Months Ended
	Dec. 31, 2015
Notes Tables
Schedule of Valuation Allowance for Impairment of Recognized Servicing Assets [Table Text Block]	Balance at Beginning of Period Provision for Bad Debt Other Accounts (1) Bad Debt Write-offs Balance at End of Period Allowance for doubtful trade receivables: Year ended December 31, 2015 $ 3,355 $ 1,333 - $ (1,582 ) $ 3,106 Year ended December 31, 2014 $ 2,409 $ 1,309 $ 146 $ (509 ) $ 3,355 Year ended December 31, 2013 $ 1,917 $ 952 - $ (460 ) $ 2,409 Balance at Beginning of Period Provision for Credit Losses Other Accounts Bad Debt Write-offs Balance at End of Period Allowance for doubtful notes receivable: Year ended December 31, 2015 $ 351 $ 26 - $ (104 ) $ 273 Year ended December 31, 2014 $ 312 $ 42 - $ (3 ) $ 351 Year ended December 31, 2013 $ 291 $ 55 - $ (34 ) $ 312

Note 1 - Organization and Sum35

Note 1 - Organization and Summary of Significant Accounting Policies (Details Textual)	12 Months Ended
	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2003USD ($)	Sep. 30, 2015USD ($)	Dec. 31, 2008USD ($)	Dec. 31, 2006USD ($)
Self Insurance Program [Member]
Restricted Cash and Cash Equivalents	$ 3,300,000	$ 3,300,000
Transportation Resource Partners [Member]
Gain on Sale of Investments	$ 208,000	1,600,000	$ 467,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures				$ 5,000,000
Total Amounts Committed to Partnership				$ 260,000,000
Joint Venture, Ownership Interest	2.20%			1.90%
Amounts Committed to Invest	$ 5,500,000						$ 5,500,000
Payments for (Proceeds from) Investments	(208,000)	(2,100,000)	(467,000)
Other than Temporary Impairment Losses, Investments	177,000	1,000,000	209,000
Investments	300,000	477,000
Transportation Resource Partners III [Member]
Amounts Committed to Invest	15,000,000					$ 15,000,000
Payments for (Proceeds from) Investments	(152,000)
Investments	11,000,000
Amounts Committed to Invest, Commitment Release	2,100,000
Remaining Investment Commitment	1,900,000
Income (Loss) from Equity Method Investments	422,000	6,100,000	$ 669,000
Equity Method Investments	$ 5,752,000	5,412,000
Equity Method Investment, Ownership Percentage	6.10%
Transportation Resource Partners IV [Member]
Amounts Committed to Invest	$ 4,900,000				$ 4,900,000
Payments for (Proceeds from) Investments	41,000
Investments	41,000
Transportation Resource Partners NTI [Member]
Amounts Committed to Invest	10,000,000
Barr-Nunn Transportation, Inc. [Member]
Finite-Lived Intangible Assets, Amortization Expense, Year Two	500,000
Finite-Lived Intangible Assets, Amortization Expense, Year Three	500,000
Finite-Lived Intangible Assets, Amortization Expense, Year Four	$ 500,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	7 years 219 days
Finite-Lived Intangible Assets, Accumulated Amortization	$ 500,000	100,000
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	500,000
Finite-Lived Intangible Assets, Amortization Expense, Year Five	400,000
Building and Building Improvements, Gross [Member]
Construction in Progress, Gross	$ 17,500,000	$ 6,900,000
Three Largest Customers [Member] | Sales Revenue, Net [Member] | Customer Concentration Risk [Member]
Concentration Risk, Percentage	11.50%	11.70%	11.00%
Three Largest Customers [Member] | Accounts Receivable [Member] | Customer Concentration Risk [Member]
Concentration Risk, Percentage	12.00%	6.70%
Single Largest Customer [Member] | Sales Revenue, Net [Member] | Customer Concentration Risk [Member]
Concentration Risk, Percentage	4.50%	4.30%	4.00%
Single Largest Customer [Member] | Accounts Receivable [Member] | Customer Concentration Risk [Member]
Concentration Risk, Percentage	1.20%	3.20%
Impairment of Long-Lived Assets Held-for-use	$ 0	$ 0	$ 0
Number of Reportable Segments	2
Interest on Note Receivable, Minimum	2.00%
Interest on Note Receivable, Maximum	20.00%
Loans Outstanding, Independent Contractors	104	109
Disposal Group, Including Discontinued Operation, Assets	$ 29,300,000	$ 23,200,000
Cost of Property Repairs and Maintenance	33,400,000	30,900,000	30,500,000
Other than Temporary Impairment Losses, Investments	177,000	1,041,000	$ 209,000
Finite-Lived Intangible Assets, Accumulated Amortization	$ 625,000	$ 125,000

Note 1 - Current and Long-term

Note 1 - Current and Long-term Balances of Notes Receivables (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Notes receivable from independent contractors	$ 794,000	$ 1,554,000
Notes receivable from third parties	3,546,000	3,882,000
Gross notes receivable	4,340,000	5,436,000
Allowance for doubtful notes receivable	(273,000)	(351,000)
Total notes receivable, net of allowance	4,067,000	5,085,000
Current portion, net of allowance	648,000	1,020,000
Long-term portion	$ 3,419,000	$ 4,065,000

Note 1 - Estimated Useful Lives

Note 1 - Estimated Useful Lives of Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2015
Land Improvements [Member] | Minimum [Member]
Useful life	5 years
Land Improvements [Member] | Maximum [Member]
Useful life	10 years
Building and Building Improvements [Member] | Minimum [Member]
Useful life	10 years
Building and Building Improvements [Member] | Maximum [Member]
Useful life	30 years
Furniture and Fixtures [Member] | Minimum [Member]
Useful life	3 years
Furniture and Fixtures [Member] | Maximum [Member]
Useful life	10 years
Shop and Service Equipment [Member] | Minimum [Member]
Useful life	2 years
Shop and Service Equipment [Member] | Maximum [Member]
Useful life	10 years
Revenue Equipment [Member] | Minimum [Member]
Useful life	5 years
Revenue Equipment [Member] | Maximum [Member]
Useful life	10 years
Leasehold Improvements [Member] | Minimum [Member]
Useful life	1 year
Leasehold Improvements [Member] | Maximum [Member]
Useful life	5 years

Note 1 - Other Long-term Assets

Note 1 - Other Long-term Assets and Restricted Cash (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Transportation Resource Partners [Member]
Investment in Transportation Resource Partners (TRP)	$ 300,000	$ 477,000
Transportation Resource Partners III [Member]
Equity Method Investments	5,752,000	5,412,000
Restricted Cash and Investments	3,282,000	3,264,000
Available-For-Sale Equity Securities	7,101,000	26,884,000
Other	2,497,000	1,243,000
	$ 18,932,000	$ 37,280,000

Note 1 - Changes in Carrying Am

Note 1 - Changes in Carrying Amount of Goodwill (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Goodwill at beginning of period	$ 47,067,000	$ 10,257,000
Acquisition		36,835,000
Amortization relating to deferred tax assets	$ (17,000)	(25,000)
Goodwill at end of period	$ 47,050,000	$ 47,067,000

Note 1 - Intangible Asset (Deta

Note 1 - Intangible Asset (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Gross carrying amount	$ 3,700,000	$ 3,700,000
Accumulated amortization	(625,000)	(125,000)
Intangible assets, net	$ 3,075,000	$ 3,575,000

Note 1 - Earnings Per Share (De

Note 1 - Earnings Per Share (Details) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Basic EPS	$ 116,718	$ 102,862	$ 69,282
Basic EPS (in shares)	81,491	80,947	79,994
Basic EPS (in dollars per share)	$ 1.43	$ 1.27	$ 0.87
Effect of stock options & restricted stock (in shares)	976	1,095	336
Diluted EPS	$ 116,718	$ 102,862	$ 69,282
Diluted EPS (in shares)	82,467	82,042	80,330
Diluted EPS (in dollars per share)	$ 1.42	$ 1.25	$ 0.86

Note 1 - Anti-dilutive Shares (

Note 1 - Anti-dilutive Shares (Details) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Number of anti-dilutive shares (in shares)	387,969	232,803	1,917,020

Note 2 - Fair Value Measureme43

Note 2 - Fair Value Measurements (Details Textual) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Available-for-sale Securities	$ 7.1	$ 26.9
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax	4.2	20
Available for Sale Securities, Accumulated Gross Unrealized Gain (Loss), Net of Tax	2.6	12.2
Available-for-sale Securities, Amortized Cost Basis	$ 2.9	$ 6.9

Note 2 - Fair Value of Financia

Note 2 - Fair Value of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Inputs, Level 1 [Member]
Available-for-sale Securities:
Equity securities - common shares	$ 7,101	$ 26,884
Money market funds	1,003	1,027
Fair Value, Inputs, Level 2 [Member]
Trading Securities:
Debt securities - municipal securities	2,279	2,237
Equity securities - common shares	7,101	26,884
Money market funds	1,003	1,027
Debt securities - municipal securities	$ 2,279	$ 2,237

Note 2 - Realized Gains on Avai

Note 2 - Realized Gains on Available-for-Sale Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Sales proceeds	$ 12,528	$ 6,355	$ 8,782
Cost of securities sold	3,937	3,190	6,857
Realized gain	8,591	3,165	1,925
Realized gains, net of taxes	$ 5,273	$ 1,932	$ 1,189

Note 3 - Line of Credit and L46

Note 3 - Line of Credit and Long-term Debt (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Revolving Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate	0.625%
Revolving Credit Facility [Member] | Unused Portion Fees [Member]
Line of Credit Facility, Interest Rate During Period	1.05%	1.31%
Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 300
Long-term Line of Credit	$ 112	$ 134.4
Line of Credit Facility, Interest Rate During Period	0.88%	0.91%
Letter of Credit [Member]
Long-term Line of Credit	$ 27.4
Line of Credit Facility, Remaining Borrowing Capacity	$ 160.6

Note 4 - Income Taxes (Details

Note 4 - Income Taxes (Details Textual)	12 Months Ended
	Dec. 31, 2015
Domestic Tax Authority [Member] | Latest Tax Year [Member]
Open Tax Year	2,015
Domestic Tax Authority [Member] | Earliest Tax Year [Member]
Open Tax Year	2,012
State and Local Jurisdiction [Member] | Latest Tax Year [Member]
Open Tax Year	2,015
State and Local Jurisdiction [Member] | Earliest Tax Year [Member]
Open Tax Year	2,011

Note 4 - Income Tax Expense (De

Note 4 - Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current income taxes:
Federal	$ 41,549	$ 42,101	$ 46,445
State	4,966	8,648	5,573
	46,515	50,749	52,018
Deferred income taxes:
Federal	19,666	12,644	(5,520)
State	1,866	4,416	182
	21,532	17,060	(5,338)
	$ 68,047	$ 67,809	$ 46,680

Note 4 - Effective Income Tax R

Note 4 - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Tax at the statutory rate (35%)	$ 65,277	$ 60,141	$ 40,846
State income taxes, net of federal benefit	4,441	8,492	3,804
Nondeductible driver per diem	1,982	1,885	1,807
Other, net	(3,653)	(2,709)	223
	$ 68,047	$ 67,809	$ 46,680

Note 4 - Effective Income Tax50

Note 4 - Effective Income Tax Rate Reconciliation (Details) (Parentheticals)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statutory rate	35.00%	35.00%	35.00%

Note 4 - Deferred Tax Assets an

Note 4 - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred Tax Assets (Liabilities), Current [Member]
Short-term deferred tax assets (liabilities):
Claims accrual		$ 6,322
Investments		(2,066)
Prepaid expenses deducted for tax purposes		(2,952)
Other, net		1,883
Long-term deferred tax liabilities (assets):
Claims accrual		6,322
Investments		2,066
Prepaid expenses deducted for tax purposes		2,952
Deferred Tax Liabilities (Assets), Noncurrent [Member]
Short-term deferred tax assets (liabilities):
Claims accrual	$ (10,578)	(4,482)
Investments	(582)	$ (7,807)
Prepaid expenses deducted for tax purposes	(2,947)
Long-term deferred tax liabilities (assets):
Property and equipment depreciation	185,678	$ 161,209
Claims accrual	(10,578)	(4,482)
Stock options	(3,837)	(2,847)
Investments	582	$ 7,807
Prepaid expenses deducted for tax purposes	2,947
Other, net	$ (627)	$ 320
Short-term deferred tax assets, net		3,187
Long-term deferred liabilities, net	$ 174,165	$ 162,007

Note 5 - Commitments and Cont52

Note 5 - Commitments and Contingencies (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2016	Feb. 29, 2016	Sep. 30, 2015	Dec. 31, 2008	Dec. 31, 2006
Transportation Resource Partners [Member]
Amounts Committed to Invest	$ 5,500,000							$ 5,500,000
Investments	300,000	$ 477,000
Transportation Resource Partners III [Member]
Amounts Committed to Invest	15,000,000						$ 15,000,000
Investments	11,000,000
Amounts Committed to Invest, Commitment Release	2,100,000
Remaining Investment Commitment	1,900,000
Transportation Resource Partners IV [Member]
Amounts Committed to Invest	4,900,000					$ 4,900,000
Investments	41,000
Transportation Resource Partners NTI [Member] | Subsequent Event [Member]
Investments					$ 10,000,000
Transportation Resource Partners NTI [Member]
Amounts Committed to Invest	10,000,000
Previous Policy Year [Member]
Estimated Litigation Liability	7,200,000	200,000
Purchase Commitment, Remaining Minimum Amount Committed	7,100,000			$ 103,000,000
Operating Leases, Rent Expense	$ 4,700,000	$ 2,800,000	$ 2,200,000

Note 5 - Future Minimum Lease P

Note 5 - Future Minimum Lease Payments (Details) $ in Thousands	Dec. 31, 2015USD ($)
2,016	$ 3,242
2,017	3,172
2,018	1,684
2,019	213
2,020	219
2,021	36
Total	$ 8,566

Note 6 - Claims Accrual (Detail

Note 6 - Claims Accrual (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2016	Mar. 01, 2016
Minimum [Member]
Self Insurance Retention	$ 1,000,000
Maximum [Member]
Self Insurance Retention	3,000,000
Self Insurance, Aggregate Losses	1,500,000
Next Policy Year [Member]
Self Insurance Retention					$ 2,500,000
Insurance and Claim Expense [Member]
Operating Insurance and Claims Costs, Production	33,400,000	$ 30,900,000
Workers Compensation Expense [Member]
Increase (Decrease) in Self Insurance Reserve	7,900,000	7,800,000
Medical Expense [Member]
Increase (Decrease) in Self Insurance Reserve	10,700,000	10,400,000
Self Retention for Employee Medical Health	225,000	225,000		$ 240,000
Self Insurance Retention, Workers Compensation Claims per Occurrence	500,000
Excess Personal Injury and Property Damage Liability Insurance	105,000,000
Insurance, Aggregate Deductible, Amount	2,500,000
Operating Insurance and Claims Costs, Production	$ 33,632,000	$ 31,133,000	$ 29,350,000

Note 6 - Current and Long-term

Note 6 - Current and Long-term Claim Reserves (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Auto Reserves [Member]
Reserves	$ 18,926,000	$ 18,075,000
Workers Compensation Reserves [Member]
Reserves	8,815,000	8,728,000
Employee Medical Reserves [Member]
Reserves	3,238,000	3,234,000
Reserves	30,979,000	30,037,000
Current portion	19,471,000	18,532,000
Long-term portion	$ 11,508,000	$ 11,505,000

Note 6 - Reconciliation of Clai

Note 6 - Reconciliation of Claim Reserves (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Barr-Nunn Transportation, Inc. [Member]
Beginning Balance		$ 30,037
Acquisition1	[1]		$ 3,209
Total reserves		30,979	30,037
Beginning Balance		30,037	24,505
Provisions recorded		52,031	49,135
Claims paid and direct expenses		(51,089)	(46,812)
Total reserves		$ 30,979	$ 30,037
[1]	Addition to claims reserve following acquisition of Barr-Nunn.

Note 7 - Annual Director Fees (

Note 7 - Annual Director Fees (Details) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Annual director fees paid through stock issuance	$ 354,168	$ 200,484	$ 167,946
Shares of common stock issued (in shares)	11,853	8,828	9,885
Dividends paid per common share (in dollars per share)	$ 0.24	$ 0.24	$ 0.24

Note 8 - Stock-Based Compensa58

Note 8 - Stock-Based Compensation and Employee Benefit Plans (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Weighted Average [Member] | Restricted Stock [Member]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition		3 years 219 days
Weighted Average [Member] | Performance Shares [Member]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition		2 years 255 days
Weighted Average [Member]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition		1 year 328 days
Minimum [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		5 years
Maximum [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		13 years
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		13,950	17,017	183,111
Restricted Stock [Member]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized		$ 10,600,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition		7 years 36 days
Performance Shares [Member]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition		3 years 36 days
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		1 year 30 days
Share-based Compensation Arrangement by Share-Based Payment Award, Payout Range, Lower Limit		0.00%
Share-based Compensation Arrangement by Share-based Payment Award, Payout Range, Upper Limit		150.00%
Share-based Compensation Arrangement by Share-based Payment Award, Payout Modifier Range, Lower Limit		75.00%
Share-based Compensation Arrangement by Share-based Payment Award, Payout Modifier Range, Upper Limit		125.00%
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		165,720	181,112
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options		$ 7,400,000
Scenario, Forecast [Member]
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Amount	$ 1,400
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares Per Employee		650,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized		3,250,000
Allocated Share-based Compensation Expense		$ 7,000,000	$ 4,500,000	$ 2,800,000
Proceeds from Stock Options Exercised		9,930,000	24,366,000	4,345,000
Employee Service Share-based Compensation, Tax Benefit Realized from Exercise of Stock Options		3,200,000	5,300,000	0
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized		$ 3,100,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition		3 years 146 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number		1,926,872
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price		$ 21.12
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Remaining Contractual Term		2 years 328 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value		$ 8,800,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value		8,300,000	17,800,000	1,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value		8,800,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value		$ 6,700,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term		2 years
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Amount		$ 1,150	$ 1,000
Defined Contribution Plan, Employer Matching Contribution, Percent of Match			50.00%
Defined Contribution Plan, Employer Discretionary Contribution Amount		$ 795,000	$ 451,000	$ 326,000

Note 8 - Fair Value Assumptions

Note 8 - Fair Value Assumptions - Stock Options (Details) - $ / shares		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock Compensation Plan [Member]
Dividend yield(1)	[1]	0.80%	1.06%	1.54%
Expected volatility(2)	[2]	25.88%	28.01%	24.92%
Risk-free interest rate(3)	[3]	0.98%	0.82%	0.34%
Weighted average fair value of options granted (in dollars per share)		$ 5	$ 3.96	$ 2.25
Expected terms(4) (in years)	[4]	2 years 270 days	2 years 270 days	2 years 270 days
Weighted average fair value of options granted (in dollars per share)		$ 5	$ 3.96	$ 2.25
[1]	Dividend yield – the dividend yield is based on our historical experience and future expectation of dividend payouts.
[2]	Expected volatility – we analyzed the volatility of our stock using historical data.
[3]	Risk-free interest rate – the risk-free interest rate assumption is based on U.S. Treasury securities at a constant maturity with a maturity period that most closely resembles the expected term of the stock option award.
[4]	Expected term - the expected term of employee stock options represents the weighted-average period the stock options are expected to remain outstanding and has been determined based on an analysis of historical exercise behavior.

Note 8 - Summary of Option Awar

Note 8 - Summary of Option Award Activity under Equity Compensation Plan (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Outstanding at beginning of year (in shares)	2,142,971	3,374,846	3,424,806
Outstanding at beginning of year (in dollars per share)	$ 17.80	$ 16.26	$ 15.99
Granted (in shares)	590,141	399,550	429,800
Granted (in dollars per share)	$ 29.81	$ 22.74	$ 15.62
Exercised (in shares)	(594,673)	(1,551,400)	(345,302)
Exercised (in dollars per share)	$ 16.65	$ 15.73	$ 12.60
Forfeited and Expired (in shares)	(129,567)	(80,025)	(134,458)
Forfeited and Expired (in dollars per share)	$ 21.76	$ 17.90	$ 16.78
Outstanding at end of year (in shares)	2,008,872	2,142,971	3,374,846
Outstanding at end of year (in dollars per share)	$ 21.41	$ 17.80	$ 16.26
Vested and exercisable at end of year (in shares)	989,396	1,383,888	2,828,365
Vested and exercisable at end of year (in dollars per share)	$ 17.45	$ 16.86	$ 16.27
Weighted average fair value of options granted (in dollars per share)	$ 5	$ 3.96	$ 2.25

Note 8 - Summary of Stock Optio

Note 8 - Summary of Stock Option Information (Details)	12 Months Ended
	Dec. 31, 2015$ / sharesshares
Range 1 [Member]
Lower exercise price (in dollars per share)
Upper exercise price (in dollars per share)	$ 14.73
Shares outstanding (in shares) | shares	2,900
Weighted Average Contractual Years Remaining	3 years 29 days
Weighted avg. exercise price per share (in dollars per share)	$ 13.34
Number vested and exercisable (in shares) | shares	1,600
Weighted avg. exercise price per share for vested and exercisable (in dollars per share)	$ 13.34
Range 2 [Member]
Lower exercise price (in dollars per share)
Upper exercise price (in dollars per share)	$ 16.83
Shares outstanding (in shares) | shares	440,031
Weighted Average Contractual Years Remaining	2 years 208 days
Weighted avg. exercise price per share (in dollars per share)	$ 15.25
Number vested and exercisable (in shares) | shares	276,231
Weighted avg. exercise price per share for vested and exercisable (in dollars per share)	$ 15.06
Range 3 [Member]
Lower exercise price (in dollars per share)
Upper exercise price (in dollars per share)	$ 18.94
Shares outstanding (in shares) | shares	693,697
Weighted Average Contractual Years Remaining	1 year 321 days
Weighted avg. exercise price per share (in dollars per share)	$ 18.05
Number vested and exercisable (in shares) | shares	649,297
Weighted avg. exercise price per share for vested and exercisable (in dollars per share)	$ 18
Range 4 [Member]
Lower exercise price (in dollars per share)
Upper exercise price (in dollars per share)	$ 33.27
Shares outstanding (in shares) | shares	872,244
Weighted Average Contractual Years Remaining	3 years 350 days
Weighted avg. exercise price per share (in dollars per share)	$ 27.21
Number vested and exercisable (in shares) | shares	62,268
Weighted avg. exercise price per share for vested and exercisable (in dollars per share)	$ 22.46
Shares outstanding (in shares) | shares	2,008,872
Weighted Average Contractual Years Remaining	2 years 343 days
Weighted avg. exercise price per share (in dollars per share)	$ 21.41
Number vested and exercisable (in shares) | shares	989,396
Weighted avg. exercise price per share for vested and exercisable (in dollars per share)	$ 17.45

Note 8 - Summary of Restricted

Note 8 - Summary of Restricted Stock Unit Award Activity under Compensation Plan (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Unvested as of January 1 (in shares)	1,073,546	1,213,698	1,210,532
Unvested as of January 1 (in dollars per share)	$ 16.22	$ 16.04	$ 16.04
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	13,950	17,017	183,111
Weighted-average fair value of PRSUs granted (in dollars per share)	$ 29.11	$ 27.63	$ 15.95
Vested (in shares)	(188,253)	(128,659)	(130,265)
Vested (in dollars per share)	$ 16.03	$ 16.07	$ 16.01
Forfeited and Expired (in shares)	(20,070)	(28,510)	(49,680)
Forfeited and Expired (in dollars per share)	$ 16.64	$ 16.23	$ 15.75
Unvested as of December 31 (in shares)	879,173	1,073,546	1,213,698
Unvested as of December 31 (in dollars per share)	$ 16.45	$ 16.22	$ 16.04

Note 8 - Fair Value Assumptio63

Note 8 - Fair Value Assumptions - Performance Shares (Details) - $ / shares		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Performance Shares [Member]
Dividend yield(1)	[1]	0.80%	1.06%
Expected volatility(2)	[2]	23.18%	26.11%
Average peer volatility (2)	[2]	30.70%	36.01%
Average peer correlation coefficient (3)	[3]	0.49%	0.5796%
Risk-free interest rate(3)	[4]	0.78%	0.66%
Expected terms(4) (in years)	[5]	2 years 229 days	2 years 292 days
Weighted-average fair value of PRSUs granted (in dollars per share)		$ 29.30	$ 23.85
Expected terms(4) (in years)	[6]	2 years 270 days	2 years 270 days
[1]	The dividend yield, used to project stock price to the end of the performance period, is based on our historical experience and future expectation of dividend payouts. Total shareholder return is determined assuming that dividends are reinvested in the issuing entity over the performance period, which is mathematically equivalent to utilizing a 0% dividend yield.
[2]	We (or peer company) estimated volatility using our (or their) historical share price performance over the remaining performance period as of the grant date.
[3]	The correlation coefficients are used to model the way in which each entity tends to move in relation to each other; the correlation assumptions were developed using the same stock price data as the volatility assumptions.
[4]	The risk-free interest rate assumption is based on U.S. Treasury securities at a constant maturity with a maturity period that most closely resembles the expected term of the performance award.
[5]	Since the Monte Carlo simulation valuation is an open form model that uses an expected life commensurate with the performance period, the expected life of the PRSUs was assumed to be the period from the grant date to the end of the performance period.
[6]	Expected term - the expected term of employee stock options represents the weighted-average period the stock options are expected to remain outstanding and has been determined based on an analysis of historical exercise behavior.

Note 8 - Summary of Award Activ

Note 8 - Summary of Award Activities (Details) - Performance Shares [Member] - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Unvested as of January 1 (in shares)	181,112	181,112
Unvested as of January 1 (in dollars per share)	$ 23.85	$ 23.85
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	165,720	181,112
Weighted-average fair value of PRSUs granted (in dollars per share)	$ 29.30	$ 23.85
Vested (in shares)
Vested (in dollars per share)
Cancelled (in shares)	(5,050)
Cancelled (in dollars per share)	$ 26.20
Unvested as of December 31 (in shares)	341,782	181,112
Unvested as of December 31 (in dollars per share)	$ 26.46	$ 23.85

Note 9 - Company Share Repurc65

Note 9 - Company Share Repurchase Program (Details Textual) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	May. 31, 2011
Treasury Stock, Shares, Acquired	1,600,000	0	0
Stock Repurchase Program, Number of Shares Authorized to be Repurchased				10,000,000
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	5,800,000

Note 10 - Segment Information66

Note 10 - Segment Information (Details Textual)	12 Months Ended
	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Trucking Segment [Member]
Number of Operating Units	$ 3
Logistics Segment [Member]
Number of Operating Units	2
Trucking Asset Based Segment [Member]
Depreciation, Depletion and Amortization	107,000,000	$ 88,200,000	$ 81,000,000
Non Asset Based Segment [Member]
Depreciation, Depletion and Amortization	$ 4,000,000	4,700,000	5,100,000
Number of Operating Segments	2
Depreciation, Depletion and Amortization	$ 111,023,000	$ 92,893,000	$ 86,129,000

Note 10 - Revenue and Operating

Note 10 - Revenue and Operating Income Between Trucking and Logistics Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014		Dec. 31, 2013
Operating Segments [Member] | Trucking Segment [Member]
Revenue	$ 952,098	$ 892,124	[1]	$ 822,188	[1]
Percentage of revenues	80.50%	80.90%		84.80%
Operating income	$ 162,143	$ 147,424		$ 106,167
Percentage of operating income	91.10%	90.60%		93.20%
Operating Segments [Member] | Logistics Segment [Member]
Revenue	$ 249,365	$ 214,378		$ 151,194
Percentage of revenues	21.10%	19.40%		15.60%
Operating income	$ 15,857	$ 15,298		$ 7,742
Percentage of operating income	8.90%	9.40%		6.80%
Operating Segments [Member]
Revenue	$ 1,201,463	$ 1,106,502		$ 973,382
Percentage of revenues
Intersegment Eliminations [Member] | Trucking Segment [Member]
Revenue	$ (163)	$ (65)		$ (120)
Percentage of revenues	0.00%	0.00%		0.00%
Intersegment Eliminations [Member] | Logistics Segment [Member]
Revenue	$ (18,336)	$ (4,105)		$ (4,025)
Percentage of revenues	(1.60%)	(0.30%)		(0.40%)
Revenue	$ 1,182,964	$ 1,102,332		$ 969,237
Percentage of revenues	100.00%	100.00%		100.00%
Operating income	$ 178,000	$ 162,722		$ 113,909
Percentage of operating income	100.00%	100.00%		100.00%
[1]	These items represent non-GAAP financial measures and are not substitutes for, and should be considered in addition to, the GAAP financial measures presented in the previous table.

Note 10 - Reconciliation of Rev

Note 10 - Reconciliation of Revenue from Segments to Consolidated, Trucking (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Operating Segments [Member] | Trucking Segment [Member]
Revenue	$ 952,098		$ 892,124	[1]	$ 822,188	[1]
Operating expenses	$ 789,955	[1]	$ 744,700		$ 716,021
Operating expenses	83.00%		83.50%		87.10%	[1]
Operating income	$ 162,143		$ 147,424		$ 106,167
Less: Trucking fuel surcharge revenue	(121,225)		(176,347)		(177,386)
Revenue, net of fuel surcharge and intersegment transactions	830,710		715,712		644,682
Operating expenses, net of fuel surcharge and intersegment transactions	$ 668,567		$ 568,288		$ 538,515
Operating expenses, net of fuel surcharge and intersegment transactions	80.50%		79.40%		83.50%
Operating Segments [Member]
Revenue	$ 1,201,463		$ 1,106,502		$ 973,382
Trucking Segment [Member] | Intersubsegment Eliminations [Member]
Revenue	(163)		(65)		(120)
Revenue	1,182,964		1,102,332		969,237
Operating expenses	1,004,964		939,610		855,328
Operating income	178,000		162,722		113,909
Less: Trucking fuel surcharge revenue	(121,225)		(176,347)		(177,386)
Revenue, net of fuel surcharge and intersegment transactions	$ 1,061,739		$ 925,985		$ 791,851
[1]	These items represent non-GAAP financial measures and are not substitutes for, and should be considered in addition to, the GAAP financial measures presented in the previous table.

Note 10 - Reconciliation of R69

Note 10 - Reconciliation of Revenue from Segments to Consolidated, Logistics (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Segments [Member] | Logistics Segment [Member]
Revenue, net of fuel surcharge and intersegment transactions	$ 249,365	$ 214,378	$ 151,194
Operating expenses	$ 233,508	$ 199,080	$ 143,452
Operating expenses	93.60%	92.90%	94.90%
Operating income	$ 15,857	$ 15,298	$ 7,742
Logistics Segment [Member] | Intersubsegment Eliminations [Member]
Revenue, net of fuel surcharge and intersegment transactions	(18,336)	(4,105)	(4,025)
Logistics Segment [Member] | Reportable Subsegments [Member]
Revenue, net of fuel surcharge and intersegment transactions	231,029	210,273	147,169
Operating expenses	$ 215,172	$ 194,975	$ 139,427
Operating expenses	93.10%	92.70%	94.70%
Operating income	$ 15,857	$ 15,298	$ 7,742
Revenue, net of fuel surcharge and intersegment transactions	1,061,739	925,985	791,851
Operating expenses	1,004,964	939,610	855,328
Operating income	$ 178,000	$ 162,722	$ 113,909

Note 10 - Gross Margin Percenta

Note 10 - Gross Margin Percentage of Segments (Details)		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Brokerage and Intermodal [Member]
Combined Brokerage and Intermodal gross margin percent(1)	[1]	16.40%	15.00%	12.50%
[1]	Gross margin percentage is based on revenue, net of intersegment elimination.

Note 11 - Acquisition of Barr71

Note 11 - Acquisition of Barr-Nunn Transportation, Inc. (Details Textual) - USD ($)	Oct. 02, 2014	Oct. 01, 2014	Dec. 31, 2014	Dec. 31, 2014	Sep. 30, 2015
Barr-Nunn Transportation, Inc. [Member]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Business Acquisition Value of Business	$ 112,400,000
Business Combination, Consideration Transferred	111,200,000	$ 110,517	$ 110,500,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Consideration Transferred				$ 700,000
Escrow Deposit	$ 8,000,000
Percentage of Acquired Business Assets			12.00%	12.00%
Percentage of Acquired Business Revenue			3.00%	3.00%
Percentage of Acquired Business Net Income			3.80%	3.80%
Business Combination, Acquisition Related Costs				$ 429,000
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High					$ 3,500,000
Business Acquisition, Percentage of Voting Interests Acquired	100.00%

Note 11 - Pro Forma Consolidate

Note 11 - Pro Forma Consolidated Results of Operations, Unaudited (Details) - Barr-Nunn Transportation, Inc. [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Total revenue	$ 1,192,745	$ 1,087,790
Net income	$ 109,787	$ 78,274

Note 11 - Allocation of the Pur

Note 11 - Allocation of the Purchase Price (Details) - USD ($)	Oct. 02, 2014	Oct. 01, 2014	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Barr-Nunn Transportation, Inc. [Member]
Business Combination, Consideration Transferred	$ 111,200,000	$ 110,517	$ 110,500,000
Historical book value of Barr-Nunn’s assets and liabilities (excluding cash)		71,656
Adjustments to recognize assets and liabilities at acquisition-date fair value:
Property, and equipment		3,349
Liabilities		(5,023)
Fair value of tangible net assets acquired		69,982
Identifiable intangibles at acquisition-date fair value		3,700
Excess of consideration transferred over the net amount of assets and liabilities recognized, including $3.5 million attributable to the fair value of a potential earn-out obligation (goodwill)		36,835
Trade receivables		11,380
Other current assets		2,316
Property and equipment		68,444
Goodwill		36,835
Total assets		122,675
Accounts payable		(3,311)
Accrued liabilities		(5,638)
Claims accruals		(3,209)	(30,037,000)	$ (30,979,000)	$ (30,037,000)
Business Combination, Consideration Transferred	$ 111,200,000	110,517	110,500,000
Cash paid pursuant to Stock Purchase and Real Estate Agreements		$ 110,517
Goodwill			47,067,000	47,050,000	47,067,000	$ 10,257,000
Claims accruals			$ (30,037,000)	(30,979,000)	(30,037,000)	$ (24,505,000)
Cash paid pursuant to Stock Purchase and Real Estate Agreements				$ 3,500,000	$ 110,517,000

Note 12 - Quarterly Financial74

Note 12 - Quarterly Financial Data (unaudited) (Details Textual)	Oct. 02, 2014
Business Acquisition, Percentage of Voting Interests Acquired	100.00%

Note 12 - Quarterly Financial I

Note 12 - Quarterly Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue, net of fuel surcharge and intersegment transactions	$ 265,972	$ 269,930	$ 268,623	$ 257,214	$ 273,653	$ 227,829	$ 218,908	$ 205,596	$ 1,061,739	$ 925,985	$ 791,851
Operating income	43,652	46,426	41,619	46,304	52,782	39,791	38,899	31,250	178,000	162,722	113,909
Net income attributable to Knight	$ 29,235	$ 30,283	$ 27,638	$ 29,563	$ 32,938	$ 25,100	$ 25,761	$ 19,064	$ 116,718	$ 102,862	$ 69,282
Basic EPS (in dollars per share)	$ 0.36	$ 0.37	$ 0.34	$ 0.36	$ 0.40	$ 0.31	$ 0.32	$ 0.24	$ 1.43	$ 1.27	$ 0.87
Diluted EPS (in dollars per share)	$ 0.36	$ 0.37	$ 0.33	$ 0.36	$ 0.40	$ 0.31	$ 0.31	$ 0.23	$ 1.42	$ 1.25	$ 0.86

Schedule II - Valuation and Q76

Schedule II - Valuation and Qualifying Accounts and Reserves (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for Trade Receivables [Member]
Balance at Beginning of Period	$ 3,355	$ 2,409	$ 1,917
Provision for Bad Debt	$ 1,333	1,309	$ 952
Other Accounts		146
Bad Debt Write-offs	$ (1,582)	(509)	$ (460)
Balance at End of Period	3,106	3,355	2,409
Allowance for Notes Receivable [Member]
Balance at Beginning of Period	351	312	291
Provision for Bad Debt	$ 26	$ 42	$ 55
Other Accounts
Bad Debt Write-offs	$ (104)	$ (3)	$ (34)
Balance at End of Period	273	351	312
Provision for Bad Debt	$ 1,359	$ 1,351	$ 1,008