Forward Air (FWRD) 10-Q 26 Jul 18 2018 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Jul. 23, 2018
Entity Information [Line Items]
Entity Registrant Name	FORWARD AIR CORP
Entity Central Index Key	912,728
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		29,348,539
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2018

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash	$ 20,102	$ 3,893
Accounts receivable, less allowance of $3,452 in 2018 and $3,006 in 2017	152,393	147,948
Other current assets	21,010	15,807
Total current assets	193,505	167,648
Property and equipment	401,507	399,235
Less accumulated depreciation and amortization	197,264	193,123
Total property and equipment, net	204,243	206,112
Goodwill and other acquired intangibles:
Goodwill	191,671	191,671
Other acquired intangibles, net of accumulated amortization of $76,033 in 2018 and $71,527 in 2017	106,741	111,247
Total goodwill and other acquired intangibles, net	298,412	302,918
Other assets	15,132	15,944
Total assets	711,292	692,622
Current liabilities:
Accounts payable	32,036	30,723
Accrued expenses	37,337	35,069
Current portion of debt and capital lease obligations	344	359
Total current liabilities	69,717	66,151
Long-term debt and capital lease obligations, less current portion	40,453	40,588
Other long-term liabilities	25,678	24,104
Deferred income taxes	33,574	29,080
Shareholders' equity:
Preferred stock	0	0
Common stock, $0.01 par value: Authorized shares - 50,000,000, Issued and outstanding shares - 29,073,811 in 2018 and 29,454,062 in 2017	291	295
Additional paid-in capital	201,373	195,346
Retained earnings	340,206	337,058
Total shareholders' equity	541,870	532,699
Total liabilities and shareholders' equity	$ 711,292	$ 692,622

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Unaudited) Parenthetical - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Accounts receivable, allowance	$ 3,452	$ 3,006
Other acquired intangibles, accumulated amortization	$ 76,033	$ 71,527
Shareholders' equity:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares (in shares)	50,000,000	50,000,000
Common stock, issued shares (in shares)	29,073,811	29,454,062
Common stock, outstanding shares (in shares)	29,073,811	29,454,062

Condensed Consolidated Statemen

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Operating revenue	$ 330,343	$ 283,876	$ 632,951	$ 545,921
Operating expenses:
Purchased transportation	155,716	131,102	295,382	248,796
Salaries, wages and employee benefits	72,073	65,018	141,655	126,946
Operating leases	18,006	14,796	35,970	30,397
Depreciation and amortization	10,362	10,219	21,052	20,252
Insurance and claims	10,086	7,730	17,238	13,536
Fuel expense	5,598	3,671	11,152	7,351
Other operating expenses	25,632	21,344	53,397	44,905
Total operating expenses	297,473	253,880	575,846	492,183
Income from operations	32,870	29,996	57,105	53,738
Other income (expense):
Interest expense	(483)	(236)	(854)	(518)
Other, net	(1)	18	(1)	(8)
Total other income (expense)	(484)	(218)	(855)	(526)
Income before income taxes	32,386	29,778	56,250	53,212
Income tax expense	8,088	10,112	14,212	18,966
Net income and comprehensive income	$ 24,298	$ 19,666	$ 42,038	$ 34,246
Net income per share:
Basic (in dollars per share)	$ 0.83	$ 0.65	$ 1.42	$ 1.13
Diluted (in dollars per share)	0.82	0.65	1.42	1.13
Common Stock [Member]
Dividends per share:
Dividends per share (in dollars per share)	$ 0.15	$ 0.15	$ 0.30	$ 0.30

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating activities:
Net income	$ 42,038	$ 34,246
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	21,052	20,252
Share-based compensation	4,678	4,026
(Gain) loss on disposal of property and equipment	(134)	507
Provision for loss on receivables	457	257
Provision for revenue adjustments	1,829	1,468
Deferred income tax	4,494	1,081
Changes in operating assets and liabilities
Accounts receivable	(6,732)	(10,484)
Prepaid expenses and other current assets	(3,639)	(3,978)
Income taxes	(1,428)	1,737
Accounts payable and accrued expenses	4,375	2,868
Net cash provided by operating activities	66,990	51,980
Investing activities:
Proceeds from disposal of property and equipment	4,839	1,339
Purchases of property and equipment	(17,606)	(4,662)
Acquisition of business, net of cash acquired	0	22,500
Other	(347)	513
Net cash used in investing activities	(13,114)	(25,310)
Financing activities:
Payments of debt and capital lease obligations	(151)	(27,933)
Proceeds from senior credit facility	0	35,000
Payments on line of credit	0	(14,500)
Proceeds from exercise of stock options	1,112	4,892
Payments of cash dividends	(8,828)	(9,082)
Repurchase of common stock (repurchase program)	(28,165)	(11,995)
Common stock issued under employee stock purchase plan	237	226
Cash settlement of share-based awards for minimum tax withholdings	(1,872)	(1,699)
Net cash used in financing activities	(37,667)	(25,091)
Net increase in cash	16,209	1,579
Cash at beginning of period	3,893	8,511
Cash at end of period	$ 20,102	$ 10,090

Description of Business and Bas

Description of Business and Basis of Presentation	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Basis of Presentation	Description of Business and Basis of Presentation Forward Air Corporation is a leading asset-light freight and logistics company. Forward Air Corporation's ("the Company", "We", "Our") services can be classified into four reportable segments: Expedited LTL, Truckload Premium Services ("TLS"), Intermodal and Pool Distribution ("Pool") (See Note 11). Through the Expedited LTL segment, we operate a comprehensive national network to provide expedited regional, inter-regional and national less-than-truckload ("LTL") services. Expedited LTL offers customers local pick-up and delivery and other services including shipment consolidation and deconsolidation, warehousing, customs brokerage and other handling. Through our TLS segment, we provide expedited truckload brokerage, dedicated fleet services, as well as high security and temperature-controlled logistics services in the United States and Canada. Our Intermodal segment provides first- and last-mile high value intermodal container drayage services both to and from seaports and railheads. Intermodal also offers dedicated contract and CFS warehouse and handling services. Today, Intermodal operates primarily in the Midwest and Southeast, with a smaller operational presence in the Southwest United States. In our Pool Distribution segment, we provide high-frequency handling and distribution of time sensitive product to numerous destinations within a specific geographic region. We offer this service throughout the Mid-Atlantic, Southeast, Midwest and Southwest United States. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and notes required by United States generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. The Company’s operating results are subject to seasonal trends (as described in our 2017 Form 10-K) when measured on a quarterly basis; therefore operating results for the six months ended June 30, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018 . For further information, refer to the consolidated financial statements and notes thereto included in the Forward Air Corporation Annual Report on Form 10-K for the year ended December 31, 2017 . The accompanying unaudited condensed consolidated financial statements of the Company include Forward Air Corporation and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Certain reclassifications have been made to the prior period financial information to conform to the current year presentation.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Jun. 30, 2018
Recent Accounting Pronouncements [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): "Simplifying the Accounting for Goodwill Impairment." Under the new standard, a goodwill impairment loss will be measured at the amount by which a reporting unit's carrying amount exceeds its fair value, not to exceed the carrying amount of goodwill, thus no longer requiring the two-step method. The guidance requires prospective adoption and will be effective for annual or interim goodwill impairment tests in fiscal years beginning after December 15, 2019. Early adoption of this guidance is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We have adopted this guidance and do not expect any impact to the consolidated financial statements. In February 2016, the FASB, issued ASU 2016-02, Leases, which introduces the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous guidance. The guidance will be effective for annual reporting periods beginning after December 15, 2018 and interim periods within those fiscal years with early adoption permitted. We are evaluating the impact of the future adoption of this standard on our consolidated financial statements. In May 2014, the FASB issued guidance on revenue from contracts with customers that superseded most current revenue recognition guidance, including industry-specific guidance. The underlying principle is that an entity will recognize revenue to depict the transfer of goods or services to customers at an amount that the entity expects to be entitled to in exchange for those goods or services. The guidance provides a five-step analysis of transactions to determine when and how revenue is recognized. Other major provisions include capitalization of certain contract costs, consideration of time value of money in the transaction price, and allowing estimates of variable consideration to be recognized before contingencies are resolved in certain circumstances. The guidance also requires enhanced disclosures regarding the nature, amount, timing and uncertainty of revenue and cash flows arising from an entity’s contracts with customers. The guidance is effective for the interim and annual periods beginning on or after December 15, 2017. The guidance permits the use of either a full retrospective or modified retrospective adoption approach with a cumulative effect adjustment recorded in either scenario as necessary upon transition. As permitted by the guidance, we implemented the use of full retrospective presentation, which required the Company to restate each prior reporting period presented. While evaluating principal versus agent relationships under the new standard, we determined that we will transition the fuel surcharge revenue stream from an agent to principal relationship. This caused this revenue stream and associated costs to be recognized on a gross basis that have historically been recognized on a net basis, increasing revenue and expenses by approximately $15,392 and $29,595 for the three and six months ended June 30, 2017, respectively, with no impact on operating income. In addition, based on a review of our customer shipping arrangements, we have concluded that revenue recognition for our performance obligations should be over time. This is because the customer will simultaneously receive and consume the benefits of these services as the entity performs over the related service period. A performance obligation is performed over time if an entity determines that another entity would not need to substantially reperform the work completed to date if another entity were to fulfill the remaining performance obligation to the applicable customer. Applying this guidance to our shipping performance obligations, if we were to move a customer’s freight partially to its destination but were unable to complete the remaining obligation, a replacement vendor would only have to complete the transit as opposed to initiating at shipment origin. Therefore, we believe our customers simultaneously receive and consume the benefits we provide and as a result we will recognize the revenue for each shipment over the course of time. Once management concluded that revenue would be recognized over time under ASC 606, management determined an appropriate measure of progress of recognizing revenue over time toward complete satisfaction of a performance obligation. Most of the Company’s services are completed in a short amount of time; therefore, a relatively small number of contracts are open as of the end of the quarter. Management concluded that the measure of progress would be days of shipping. For example, if a transportation service performance obligation takes three days to complete and a quarter ends on day two of the services, management would recognize two-thirds of the revenue for the transportation performance obligation. Our revenue from contracts with customers is disclosed within our four reportable segments: Expedited LTL, TLS, Intermodal and Pool. This is consistent with our disclosures in earnings releases and annual reports and with the information regularly reviewed by the chief operating decision maker for evaluating financial performance. We recast certain prior period amounts to conform with the adoption of the revenue recognition standard, as shown in the "As Adjusted" columns of the following tables: Three months ended June 30, 2017 (In thousands, except per share data) As Previously Reported Adjustments As Adjusted Income Statement: Revenue LTL revenue $ 152,270 $ 8,202 $ 160,472 Truckload Premium Services 45,186 5,265 50,451 Pool Distribution 36,835 921 37,756 Intermodal 35,270 1,970 37,240 Eliminations and other operations (2,043 ) — (2,043 ) Consolidated revenue 267,518 16,358 283,876 Operating Expenses 237,709 16,171 253,880 Income from operations 29,809 187 29,996 Income tax expenses 10,041 71 10,112 Net Income 19,550 116 19,666 Diluted earnings per share $ 0.64 $ 0.01 $ 0.65 Six months ended June 30, 2017 (In thousands, except per share data) As Previously Reported Adjustments As Adjusted Income Statement: Revenue LTL revenue $ 292,868 $ 16,369 $ 309,237 Truckload Premium Services 86,971 10,567 97,538 Pool Distribution 74,658 1,900 76,558 Intermodal 63,561 2,586 66,147 Eliminations and other operations (3,559 ) — (3,559 ) Consolidated revenue 514,499 31,422 545,921 Operating Expenses 461,502 30,681 492,183 Income from operations 52,997 741 53,738 Income tax expenses 18,678 288 18,966 Net Income 33,793 453 34,246 Diluted earnings per share $ 1.11 $ 0.02 $ 1.13

Acquisitions and Goodwill

Acquisitions and Goodwill	6 Months Ended
	Jun. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Acquisitions and Goodwill	Acquisitions and Goodwill Intermodal Acquisitions As part of the Company's strategy to expand its Intermodal operations, in May 2017, we acquired certain assets of Atlantic Trucking Company, Inc., Heavy Duty Equipment Leasing, LLC, Atlantic Logistics, LLC and Transportation Holdings, Inc. (together referred to as “Atlantic” in this note) for $22,500 and a potential earnout of $1,000 . The acquisition was funded by a combination of cash on hand and funds from our revolving credit facility. Atlantic was a privately held provider of intermodal, drayage and related services headquartered in Charleston, South Carolina. It also has terminal operations in Atlanta, Charlotte, Houston, Jacksonville, Memphis, Nashville, Norfolk and Savannah. These locations allowed Intermodal to significantly expand its footprint in the southeastern region. In October 2017, we also acquired certain assets of Kansas City Logistics, LLC ("KCL") for $640 and an earnout of $100 paid in the second quarter of 2018. KCL provided Intermodal with an expanded footprint in the Kansas and Missouri markets. The assets, liabilities, and operating results of these collective acquisitions have been included in the Company's consolidated financial statements from their dates of acquisition and have been included in the Intermodal reportable segment. Allocations of Purchase Prices The following table presents the allocation of the Atlantic and KCL purchase prices to the assets acquired and liabilities assumed based on their estimated fair values and resulting residual goodwill (in thousands): Atlantic KCL May 7, 2017 October 22, 2017 Tangible assets: Property and equipment $ 1,821 $ 223 Total tangible assets 1,821 223 Intangible assets: Non-compete agreements 1,150 6 Customer relationships 13,400 234 Goodwill 6,719 277 Total intangible assets 21,269 517 Total assets acquired 23,090 740 Liabilities assumed: Current liabilities 590 100 Total liabilities assumed 590 100 Net assets acquired $ 22,500 $ 640 The acquired definite-lived intangible assets have the following useful lives: Useful Lives Atlantic KCL Customer relationships 15 years 15 years Non-compete agreements 5 years 2 years The fair value of the non-compete agreements and customer relationships assets were estimated using an income approach. The Company's inputs into fair value estimates are classified within level 3 of the fair value hierarchy as defined in the FASB Accounting Standards Codification and the Hierarchy of Generally Accepted Accounting Principles (“the FASB Codification”). Under this method, an intangible asset's fair value is equal to the present value of the incremental after-tax cash flows (excess earnings) attributable solely to the intangible asset over its remaining useful life. To estimate fair value, the Company used cash flows discounted at rates considered appropriate given the inherent risks associated with each type of asset. The Company believes that the level and timing of cash flows appropriately reflect market participant assumptions. Cash flows were assumed to extend through the remaining economic useful life of each class of intangible asset. Goodwill The Company conducted its annual impairment assessments and test of goodwill for each reporting unit as of June 30, 2018 and no impairment charges were required. The first step of the goodwill impairment test is the Company's assessment of qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than the reporting unit's carrying amount, including goodwill. When performing the qualitative assessment, the Company considers the impact of factors including, but not limited to, macroeconomic and industry conditions, overall financial performance of each reporting unit, litigation and new legislation. If based on the qualitative assessments, the Company believes it more likely than not that the fair value of a reporting unit is less than the reporting unit's carrying amount, or periodically as deemed appropriate by management, the Company will prepare an estimation of the respective reporting unit's fair value utilizing a quantitative approach. If a quantitative fair value estimation is required, the Company estimates the fair value of the applicable reporting units, using a combination of discounted projected cash flows and market valuations for comparable companies as of the valuation date (level 3). If this estimation of fair value indicates that impairment potentially exists, the Company will then measure the amount of the impairment, if any. Goodwill impairment exists when the estimated implied fair value of goodwill is less than its carrying value. Changes in strategy or market conditions could significantly impact these fair value estimates and require adjustments to recorded asset balances. We have five reporting units - Expedited LTL, TLX Forward Air, Intermodal, Pool Distribution and Total Quality, Inc. ("TQI"). The TLX Forward Air and the TQI reporting units are assigned to the Truckload Premium Services reportable segment. Currently, there is no goodwill assigned to the TLX Forward Air reporting unit. Our 2018 calculations for LTL, Pool Distribution, Intermodal and TQI indicated that, as of June 30, 2018, the fair value of each reporting unit exceeded their carrying value by approximately 349.0% , 182.0% , 73.0% and 36.0% , respectively. For our 2018 analysis, the significant assumptions used for the income approach were projected net cash flows and the following discount and long-term growth rates: Expedited LTL Pool Intermodal TQI Discount rate 12.0 % 15.5 % 14.0 % 16.5 % Long-term growth rate 4.0 % 4.0 % 4.0 % 4.0 % The estimates used to calculate the fair value of each reporting unit change from year to year based on operating results, market conditions, and other factors. Changes in these estimates and assumptions could materially affect the determination of the reporting unit's fair value and goodwill impairment for the reporting unit. There were no changes to goodwill for the six months ended June 30, 2018 . Approximately $112,527 of goodwill is deductible for tax purposes. The following is a summary of the goodwill balances as of June 30, 2018 . Ending balance, June 30, 2018 Expedited LTL Goodwill $ 97,593 Accumulated Impairment — TLS Goodwill 45,164 Accumulated Impairment (25,686 ) Pool Distribution Goodwill 12,359 Accumulated Impairment (6,953 ) Intermodal Goodwill 69,194 Accumulated Impairment — Total $ 191,671

Share-Based Payments

Share-Based Payments	6 Months Ended
	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Payments	Share-Based Payments The Company’s general practice has been to make a single annual grant of share-based compensation to key employees and to make other employee grants only in connection with new employment or promotions. Forms of share-based compensation granted to employees by the Company include stock options, non-vested shares of common stock (“non-vested share”), and performance shares. The Company also typically makes a single annual grant of non-vested shares to non-employee directors in conjunction with the annual election of non-employee directors to the Board of Directors. Share-based compensation is based on the grant date fair value of the instrument and is recognized ratably over the requisite service period, or vesting period. All share-based compensation expense is recognized in salaries, wages and employee benefits. Employee Activity - Stock Options Stock option grants to employees generally expire seven years from the grant date and typically vest ratably over a three -year period. The Company used the Black-Scholes option-pricing model to estimate the grant-date fair value of options granted. The weighted-average fair value of options granted and assumptions used to estimate their fair value during the six months ended June 30, 2018 and 2017 were as follows: Six months ended June 30, June 30, Expected dividend yield 1.1 % 1.3 % Expected stock price volatility 24.9 % 28.7 % Weighted average risk-free interest rate 2.6 % 2.0 % Expected life of options (years) 6.0 6.0 Weighted average grant date fair value $ 15 $ 13 The following tables summarize the Company’s employee stock option activity and related information: Three months ended June 30, June 30, Share-based compensation for options $ 346 $ 331 Six months ended June 30, 2018 Weighted- Weighted- Aggregate Average Average Intrinsic Remaining Options Exercise Value Contractual (000) Price (000) Term Outstanding at December 31, 2017 440 $ 45 Granted 86 59 Exercised (26 ) 42 Forfeited — — Outstanding at June 30, 2018 500 $ 47 $ 4,985 4.4 Exercisable at June 30, 2018 287 $ 44 $ 3,853 3.3 Six months ended June 30, June 30, Share-based compensation for options $ 688 $ 699 Tax benefit for option compensation $ 172 $ 254 Unrecognized compensation cost for options, net of estimated forfeitures $ 2,243 $ 2,281 Weighted average period over which unrecognized compensation will be recognized (years) 2.0 Employee Activity - Non-vested Shares Non-vested share grants to employees vest ratably over a three -year period. The non-vested shares’ fair values were estimated using closing market prices on the day of grant. The following tables summarize the Company’s employee non-vested share activity and related information: Three months ended June 30, June 30, Share-based compensation for non-vested shares $ 1,566 $ 1,279 Six months ended June 30, 2018 Weighted- Aggregate Non-vested Average Grant Date Shares Grant Date Fair Value (000) Fair Value (000) Outstanding and non-vested at December 31, 2017 227 $ 47 Granted 174 59 Vested (107 ) 56 Forfeited (2 ) 52 Outstanding and non-vested at June 30, 2018 292 $ 54 $ 15,758 Six months ended June 30, June 30, Share-based compensation for non-vested shares $ 2,965 $ 2,518 Tax benefit for non-vested share compensation $ 741 $ 917 Unrecognized compensation cost for non-vested shares, net of estimated forfeitures $ 13,371 $ 8,826 Weighted average period over which unrecognized compensation will be recognized (years) 2.0 Employee Activity - Performance Shares The Company annually grants performance shares to key employees. Under the terms of the performance share agreements, following the end of a three-year performance period, the Company will issue to the employees a calculated number of common stock shares based on the three year performance of the Company’s total shareholder return as compared to the total shareholder return of a selected peer group. No shares may be issued if the Company's total shareholder return outperforms 25% or less of the peer group, but the number of shares issued may be doubled if the Company's total shareholder return performs better than 90% of the peer group. The fair value of the performance shares was estimated using a Monte Carlo simulation. The weighted average assumptions used in the Monte Carlo estimate were as follows: Six months ended June 30, June 30, Expected stock price volatility 24.3 % 24.7 % Weighted average risk-free interest rate 2.2 % 1.4 % The following tables summarize the Company’s employee performance share activity, assuming median share awards, and related information: Three months ended June 30, June 30, Share-based compensation for performance shares $ 307 $ 257 Six months ended June 30, 2018 Weighted- Aggregate Performance Average Grant Date Shares Grant Date Fair Value (000) Fair Value (000) Outstanding and non-vested at December 31, 2017 69 $ 58 Granted 18 72 Additional shares awarded based on performance — — Vested — — Forfeited (22 ) 67 Outstanding and non-vested at June 30, 2018 65 $ 58 $ 3,795 Six months ended June 30, June 30, Share-based compensation for performance shares $ 642 $ 441 Tax benefit for performance share compensation $ 161 $ 160 Unrecognized compensation cost for performance shares, net of estimated forfeitures $ 2,036 $ 2,135 Weighted average period over which unrecognized compensation will be recognized (years) 2.0 Employee Activity - Employee Stock Purchase Plan Under the 2005 Employee Stock Purchase Plan (the “ESPP”), which has been approved by shareholders, the Company is authorized to issue up to a remaining 367,309 shares of common stock to employees of the Company. These shares may be issued at a price equal to 90% of the lesser of the market value on the first day or the last day of each six-month purchase period. Common stock purchases are paid for through periodic payroll deductions and/or up to two large lump sum contributions. For the six months ended June 30, 2018, participants under the plan purchased 4,550 shares at an average price of $51.98 per share. For the six months ended June 30, 2017, participants under the plan purchased 5,188 shares at an average price of $43.59 per share. The weighted-average fair value of each purchase right under the ESPP granted for the six months ended June 30, 2018, which is equal to the discount from the market value of the common stock at the end of each six month purchase period, was $7.10 per share. The weighted-average fair value of each purchase right under the ESPP granted for the six months ended June 30, 2017, which is equal to the discount from the market value of the common stock at the end of each six month purchase period, was $9.69 per share. Share-based compensation expense of $32 and $51 was recognized during the three and six months ended June 30, 2018 and 2017, respectively. Non-employee Director Activity - Non-vested Shares Grants of non-vested shares to non-employee directors vest ratably over the elected term to the Board of Directors, or approximately one year. The following tables summarize the Company’s non-employee non-vested share activity and related information: Three months ended June 30, June 30, Share-based compensation for non-vested shares $ 166 $ 146 Six months ended June 30, 2018 Weighted- Aggregate Non-vested Average Grant Date Shares Grant Date Fair Value (000) Fair Value (000) Outstanding and non-vested at December 31, 2017 11 $ 52 Granted 15 58 Vested (12 ) 52 Forfeited — — Outstanding and non-vested at June 30, 2018 14 $ 58 $ 805 Six months ended June 30, June 30, Share-based compensation for non-vested shares $ 351 $ 317 Tax benefit for non-vested share compensation $ 88 $ 115 Unrecognized compensation cost for non-vested shares, net of estimated forfeitures $ 703 $ 442 Weighted average period over which unrecognized compensation will be recognized (years) 0.9

Senior Credit Facility

Senior Credit Facility	6 Months Ended
	Jun. 30, 2018
Senior Credit Facility [Abstract]
Senior Credit Facility	Senior Credit Facility On September 29, 2017, the Company, entered into a five -year senior unsecured revolving credit facility (the “Facility”) with a maximum aggregate principal amount of $150,000 , with a sublimit of $30,000 for letters of credit and a sublimit of $30,000 for swing line loans. The Facility may be increased by up to $100,000 to a maximum aggregate principal amount of $250,000 pursuant to the terms of the credit agreement, subject to the lenders’ agreement to increase their commitments or the addition of new lenders extending such commitments. Such increases to the Facility may be in the form of additional revolving credit loans, term loans or a combination thereof, and are contingent upon there being no events of default under the Facility and satisfaction of other conditions precedent and are subject to the other limitations set forth in the credit agreement. The Facility is scheduled to mature in September 2022 and may be used to refinance existing indebtedness of the Company and for working capital, capital expenditures and other general corporate purposes. The Facility refinanced the Company’s existing obligations for its unsecured credit facility under the credit agreement dated as of February 4, 2015, as amended, which was terminated as of the date of the new Facility. Unless the Company elects otherwise under the credit agreement, interest on borrowings under the Facility is based on the highest of (a) the federal funds rate (not less than 0%) plus 0.5% , (b) the administrative agent's prime rate and (c) the LIBOR Rate plus 1.0% , in each case plus a margin that can range from 0.3% to 0.8% with respect to the Facility depending on the Company’s ratio of consolidated funded indebtedness to earnings before interest, taxes, depreciation and amortization, as set forth in the credit agreement. Payments of interest for each loan that is based on the LIBOR Rate are due in arrears on the last day of the interest period applicable to such loan (with interest periods of one, two or three months being available, at the Company’s option). Payments of interest on loans that are not based on the LIBOR Rate are due on the last day of each quarter ended March 31, June 30, September 30 and December 31 of each year. All unpaid amounts of principal and interest are due at maturity. As of June 30, 2018 , we had $40,500 in borrowings outstanding under the revolving credit facility, $11,039 utilized for outstanding letters of credit and $98,461 of available borrowing capacity under the revolving credit facility. The interest rate on the outstanding borrowing under the revolving credit facility was 3.6% at June 30, 2018. The Facility contains customary events of default including, among other things, payment defaults, breach of covenants, cross acceleration to material indebtedness, bankruptcy-related defaults, material judgment defaults, and the occurrence of certain change of control events. The occurrence of an event of default may result in, among other things, the termination of the Facilities, acceleration of repayment obligations and the exercise of remedies by the lenders with respect to the Company and its subsidiaries that are party to the Facility. The Facility also contains financial covenants and other covenants that, among other things, restrict the ability of the Company and its subsidiaries, without the approval of the required lenders, to engage in certain mergers, consolidations, asset sales, dividends and stock repurchases, investments, and other transactions or to incur liens or indebtedness in excess of agreed thresholds, as set forth in the credit agreement. As of June 30, 2018, the Company was in compliance with the aforementioned covenants.

Net Income Per Share

Net Income Per Share	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
Net Income Per Share	Net Income Per Share The following table sets forth the computation of basic and diluted net income per share: Three months ended Six months ended June 30, June 30, June 30, June 30, (As Adjusted) (As Adjusted) Numerator: Net income and comprehensive income $ 24,298 $ 19,666 $ 42,038 $ 34,246 Income allocated to participating securities (209 ) (160 ) (359 ) (281 ) Numerator for basic and diluted income per share - net income $ 24,089 $ 19,506 $ 41,679 $ 33,965 Denominator (in thousands): Denominator for basic income per share - weighted-average shares 29,169 30,026 29,288 30,029 Effect of dilutive stock options (in thousands) 74 61 71 68 Effect of dilutive performance shares (in thousands) 29 27 32 30 Denominator for diluted income per share - adjusted weighted-average shares 29,272 30,114 29,391 30,127 Basic net income per share $ 0.83 $ 0.65 $ 1.42 $ 1.13 Diluted net income per share $ 0.82 $ 0.65 $ 1.42 $ 1.13 The number of instruments that could potentially dilute net income per basic share in the future, but that were not included in the computation of net income per diluted share because to do so would have been anti-dilutive for the periods presented, are as follows: June 30, June 30, Anti-dilutive stock options (in thousands) 82 284 Anti-dilutive performance shares (in thousands) 15 19 Anti-dilutive non-vested shares and deferred stock units (in thousands) 5 — Total anti-dilutive shares (in thousands) 102 303

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Tax Reform On December 22, 2017, President Trump signed into law H.R. 1, “An Act to provide for reconciliation pursuant to titles II and V of the concurrent resolution on the budget for fiscal year 2018” (this legislation was formerly called the “Tax Cuts and Jobs Act” and is referred to herein as the “U.S. Tax Act”). The U.S. Tax Act provides for significant changes in the U.S. Internal Revenue Code of 1986, as amended. The U.S. Tax Act contains provisions with separate effective dates but is generally effective for taxable years beginning after December 31, 2017. Beginning on January 1, 2018, the U.S. Tax Act lowers the U.S. corporate income tax rate from 35% to 21% on our U.S. earnings from that date and beyond. The ultimate impact of the U.S. Tax Act on our reported results in 2018 may differ from the estimates provided herein, possibly materially, due to, among other things, changes in interpretations and assumptions we have made, guidance that may be issued, and other actions we may take as a result of the U.S. Tax Act different from that presently contemplated. On December 22, 2017, the SEC staff issued SAB 118 that allows us to record provisional amounts during a measurement period not to extend beyond one year of the enactment date. We currently are analyzing the 2017 Tax Act, and in certain areas, have made reasonable estimates of the effects on our consolidated financial statements and tax disclosures, including the changes to our existing deferred tax balances. Tax Rate For the three months ended June 30, 2018 and 2017, the effective income tax rates varied from the statutory federal income tax rate of 21.0% and 35.0% , primarily as a result of the effect of state income taxes, net of the federal benefit, and permanent differences between book and tax net income. The combined federal and state effective tax rate for the six months ended June 30, 2018 was 25.3% compared to a rate of 35.6% for the same period in 2017. The lower effective tax rate for the six months ended June 30, 2018 is the result of the enactment of the U.S. Tax Act, which lowered the statutory federal income tax rate to 21.0% from 35.0%. The lower rate was partly offset by fuel tax benefits taken in the six months ended June 30, 2018 that were not deductible for tax purposes and 2017 benefiting from qualified production property deductions that were not renewed in the U.S. Tax Act.

Financial Instruments

Financial Instruments	6 Months Ended
	Jun. 30, 2018
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Financial Instruments	Financial Instruments Fair Value of Financial Instruments The following methods and assumptions were used by the Company in estimating its fair value disclosures for financial instruments: Accounts receivable and accounts payable: The carrying amounts reported in the balance sheet for accounts receivable and accounts payable approximate their fair value based on their short-term nature. The Company’s revolving credit facility bears variable interest rates plus additional basis points based upon covenants related to total indebtedness to earnings. As the revolving credit facility bears a variable interest rate, the carrying value approximates fair value. Using interest rate quotes and discounted cash flows, the Company estimated the fair value of its outstanding capital lease obligations as follows: June 30, 2018 Carrying Value Fair Value Capital leases $ 544 $ 565 The Company's fair value estimates for the above financial instruments are classified within level 3 of the fair value hierarchy.

Shareholders' Equity

Shareholders' Equity	6 Months Ended
	Jun. 30, 2018
Stockholders' Equity Note [Abstract]
Shareholders' Equity	Shareholders' Equity During each quarter of 2017 and the first and second quarters of 2018, our Board of Directors declared a cash dividend of $0.15 per share of common stock. The Company expects to continue to pay regular quarterly cash dividends, though each subsequent quarterly dividend is subject to review and approval by the Board of Directors. On July 21, 2016, our Board of Directors approved a stock repurchase authorization for up to three million shares of the Company’s common stock. The following table summarizes our share repurchases for the three and six months ended June 30, 2018 and 2017. Three months ended Six months ended June 30, 2018 June 30, 2017 June 30, 2018 June 30, 2017 Shares repurchased 132,880 42,055 497,166 246,864 Cost of shares repurchased $ 8,172 $ 1,999 $ 28,165 $ 11,995 Average cost per share $ 61.50 $ 47.54 $ 56.65 $ 48.59 As of June 30, 2018, 1,321,499 shares were available to be purchased under the 2016 Plan.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2018
Commitments and Contingencies [Abstract]
Commitments and Contingencies	Commitments and Contingencies From time to time, the Company is party to ordinary, routine litigation incidental to and arising in the normal course of business. The Company does not believe that any of these pending actions, individually or in the aggregate, will have a material adverse effect on its business, financial condition or results of operations. The primary claims in the Company’s business relate to workers’ compensation, property damage, vehicle liability and medical benefits. Most of the Company’s insurance coverage provides for self-insurance levels with primary and excess coverage which management believes is sufficient to adequately protect the Company from catastrophic claims. We renewed our liability insurance policies on April 1, 2018 and took on additional risk exposure for vehicle liability claims by increasing our self-insurance retention and deductible levels. See “Item 1A - Risk Factors” for additional details related to the risks of our insurance coverage. In the opinion of management, adequate provision has been made for all incurred claims up to the self-insured limits, including provision for estimated claims incurred but not reported. The Company estimates its self-insurance loss exposure by evaluating the merits and circumstances surrounding individual known claims and by performing hindsight and actuarial analysis to determine an estimate of probable losses on claims incurred but not reported. Such losses should be realized immediately as the events underlying the claims have already occurred as of the balance sheet dates. Because of the uncertainty of the ultimate resolution of outstanding claims, as well as uncertainty regarding claims incurred but not reported, it is possible that management’s provision for these losses could change materially in the near term. However, no estimate can currently be made of the range of additional loss that is at least reasonably possible.

Segment Reporting

Segment Reporting	6 Months Ended
	Jun. 30, 2018
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting The Company operates in four reportable segments based on information available to and used by the chief operating decision maker. Expedited LTL operates a comprehensive national network that provides expedited regional, inter-regional and national LTL services. The TLS segment provides expedited truckload brokerage, dedicated fleet services and high security and temperature-controlled logistics services. The Intermodal segment primarily provides first- and last-mile high value intermodal container drayage services both to and from seaports and railheads. Pool Distribution provides high-frequency handling and distribution of time sensitive product to numerous destinations. Except for certain insurance activity, the accounting policies of the segments are the same as those described in the summary of significant accounting policies disclosed in Note 1 of the Forward Air Corporation Annual Report on Form 10-K for the year ended December 31, 2017 . For workers compensation and vehicle claims each segment is charged an insurance premium and is also charged a deductible that corresponds with each segment's individual self retention limit. However, any losses beyond our deductibles and any loss development factors applied to our outstanding claims as a result of actuarial analysis are not passed to the segments, but reported at the corporate level ("Eliminations & other"). Segment data includes intersegment revenues and shared costs. Costs of the corporate headquarters, shared services and shared assets, such as trailers, are allocated to the segments based on usage. The cost basis of shared assets are not allocated. The basis for the majority of shared assets, such as trailers, are included in Expedited LTL. The Company evaluates the performance of its segments based on income from operations. The Company’s business is conducted in the U.S. and Canada. The following tables summarize segment information about results from operations and assets used by the chief operating decision maker of the Company in making decisions regarding allocation of assets and resources as of and for the three and six months ended June 30, 2018 and 2017. Three months ended June 30, 2018 Expedited LTL Truckload Premium Pool Distribution Intermodal Eliminations & other Consolidated External revenues $ 191,159 $ 46,903 $ 43,197 $ 49,084 $ — $ 330,343 Intersegment revenues 1,732 2,044 108 78 (3,962 ) — Depreciation and amortization 5,557 1,562 1,705 1,537 1 10,362 Share-based compensation expense 1,877 166 113 210 51 2,417 Interest expense — 2 — 24 457 483 Income from operations 26,526 1,717 1,589 5,543 (2,505 ) 32,870 Total assets 658,125 69,082 58,695 151,962 (226,572 ) 711,292 Capital expenditures 10,648 36 576 125 — 11,385 Three months ended June 30, 2017 (As Adjusted) Expedited LTL Truckload Premium Pool Distribution Intermodal Eliminations & other Consolidated External revenues $ 159,842 $ 49,129 $ 37,685 $ 37,220 $ — $ 283,876 Intersegment revenues 630 1,322 71 20 (2,043 ) — Depreciation and amortization 5,520 1,590 1,613 1,496 — 10,219 Share-based compensation expense 1,731 85 119 129 — 2,064 Interest expense 1 — — 13 222 236 Income (loss) from operations 23,047 1,855 1,625 3,209 260 29,996 Total assets 629,098 57,933 51,214 145,343 (219,320 ) 664,268 Capital expenditures 1,756 2 203 49 — 2,010 Six months ended June 30, 2018 Expedited LTL Truckload Premium Pool Distribution Intermodal Eliminations & other Consolidated External revenues $ 359,521 $ 90,064 $ 85,804 $ 97,562 $ — $ 632,951 Intersegment revenues 3,314 4,976 172 169 (8,631 ) — Depreciation and amortization 11,085 3,320 3,509 3,138 — 21,052 Share-based compensation expense 3,553 345 229 500 51 4,678 Interest expense 1 3 — 37 813 854 Income (loss) from operations 47,298 1,674 2,960 9,012 (3,839 ) 57,105 Total assets 658,125 69,082 58,695 151,962 (226,572 ) 711,292 Capital expenditures 16,705 40 654 207 — 17,606 Six months ended June 30, 2017 (As Adjusted) Expedited LTL Truckload Premium Pool Distribution Intermodal Eliminations & other Consolidated External revenues $ 308,021 $ 95,368 $ 76,416 $ 66,116 $ — $ 545,921 Intersegment revenues 1,216 2,170 142 31 (3,559 ) — Depreciation and amortization 11,084 3,147 3,415 2,606 — 20,252 Share-based compensation expense 3,377 180 207 262 — 4,026 Interest expense 2 — — 24 492 518 Income (loss) from operations 41,975 3,610 2,991 5,763 (601 ) 53,738 Total assets 629,098 57,933 51,214 145,343 (219,320 ) 664,268 Capital expenditures 4,267 8 286 101 — 4,662

Recent Accounting Pronounceme17

Recent Accounting Pronouncements Recent Accounting Pronouncements (Tables)	6 Months Ended
	Jun. 30, 2018
Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block]	We recast certain prior period amounts to conform with the adoption of the revenue recognition standard, as shown in the "As Adjusted" columns of the following tables: Three months ended June 30, 2017 (In thousands, except per share data) As Previously Reported Adjustments As Adjusted Income Statement: Revenue LTL revenue $ 152,270 $ 8,202 $ 160,472 Truckload Premium Services 45,186 5,265 50,451 Pool Distribution 36,835 921 37,756 Intermodal 35,270 1,970 37,240 Eliminations and other operations (2,043 ) — (2,043 ) Consolidated revenue 267,518 16,358 283,876 Operating Expenses 237,709 16,171 253,880 Income from operations 29,809 187 29,996 Income tax expenses 10,041 71 10,112 Net Income 19,550 116 19,666 Diluted earnings per share $ 0.64 $ 0.01 $ 0.65 Six months ended June 30, 2017 (In thousands, except per share data) As Previously Reported Adjustments As Adjusted Income Statement: Revenue LTL revenue $ 292,868 $ 16,369 $ 309,237 Truckload Premium Services 86,971 10,567 97,538 Pool Distribution 74,658 1,900 76,558 Intermodal 63,561 2,586 66,147 Eliminations and other operations (3,559 ) — (3,559 ) Consolidated revenue 514,499 31,422 545,921 Operating Expenses 461,502 30,681 492,183 Income from operations 52,997 741 53,738 Income tax expenses 18,678 288 18,966 Net Income 33,793 453 34,246 Diluted earnings per share $ 1.11 $ 0.02 $ 1.13

Acquisitions and Goodwill (Tabl

Acquisitions and Goodwill (Tables)	6 Months Ended
	Jun. 30, 2018
Goodwill [Line Items]
Schedule of Purchase Price Allocation [Table Text Block]	The following table presents the allocation of the Atlantic and KCL purchase prices to the assets acquired and liabilities assumed based on their estimated fair values and resulting residual goodwill (in thousands): Atlantic KCL May 7, 2017 October 22, 2017 Tangible assets: Property and equipment $ 1,821 $ 223 Total tangible assets 1,821 223 Intangible assets: Non-compete agreements 1,150 6 Customer relationships 13,400 234 Goodwill 6,719 277 Total intangible assets 21,269 517 Total assets acquired 23,090 740 Liabilities assumed: Current liabilities 590 100 Total liabilities assumed 590 100 Net assets acquired $ 22,500 $ 640
Schedule of Acquired Finite-Lived Intangible Assets by Major Class [Table Text Block]	The acquired definite-lived intangible assets have the following useful lives: Useful Lives Atlantic KCL Customer relationships 15 years 15 years Non-compete agreements 5 years 2 years
Schedule of Significant Assumptions Used [Table Text Block]	For our 2018 analysis, the significant assumptions used for the income approach were projected net cash flows and the following discount and long-term growth rates: Expedited LTL Pool Intermodal TQI Discount rate 12.0 % 15.5 % 14.0 % 16.5 % Long-term growth rate 4.0 % 4.0 % 4.0 % 4.0 %
Schedule of Goodwill [Table Text Block]	There were no changes to goodwill for the six months ended June 30, 2018 . Approximately $112,527 of goodwill is deductible for tax purposes. The following is a summary of the goodwill balances as of June 30, 2018 . Ending balance, June 30, 2018 Expedited LTL Goodwill $ 97,593 Accumulated Impairment — TLS Goodwill 45,164 Accumulated Impairment (25,686 ) Pool Distribution Goodwill 12,359 Accumulated Impairment (6,953 ) Intermodal Goodwill 69,194 Accumulated Impairment — Total $ 191,671

Share-Based Payments (Tables)

Share-Based Payments (Tables)	6 Months Ended
	Jun. 30, 2018
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation, Activity [Table Text Block]	The weighted-average fair value of options granted and assumptions used to estimate their fair value during the six months ended June 30, 2018 and 2017 were as follows: Six months ended June 30, June 30, Expected dividend yield 1.1 % 1.3 % Expected stock price volatility 24.9 % 28.7 % Weighted average risk-free interest rate 2.6 % 2.0 % Expected life of options (years) 6.0 6.0 Weighted average grant date fair value $ 15 $ 13 The following tables summarize the Company’s employee stock option activity and related information: Three months ended June 30, June 30, Share-based compensation for options $ 346 $ 331 Six months ended June 30, 2018 Weighted- Weighted- Aggregate Average Average Intrinsic Remaining Options Exercise Value Contractual (000) Price (000) Term Outstanding at December 31, 2017 440 $ 45 Granted 86 59 Exercised (26 ) 42 Forfeited — — Outstanding at June 30, 2018 500 $ 47 $ 4,985 4.4 Exercisable at June 30, 2018 287 $ 44 $ 3,853 3.3 Six months ended June 30, June 30, Share-based compensation for options $ 688 $ 699 Tax benefit for option compensation $ 172 $ 254 Unrecognized compensation cost for options, net of estimated forfeitures $ 2,243 $ 2,281 Weighted average period over which unrecognized compensation will be recognized (years) 2.0
Employee Non-vested Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block]	The following tables summarize the Company’s employee non-vested share activity and related information: Three months ended June 30, June 30, Share-based compensation for non-vested shares $ 1,566 $ 1,279 Six months ended June 30, 2018 Weighted- Aggregate Non-vested Average Grant Date Shares Grant Date Fair Value (000) Fair Value (000) Outstanding and non-vested at December 31, 2017 227 $ 47 Granted 174 59 Vested (107 ) 56 Forfeited (2 ) 52 Outstanding and non-vested at June 30, 2018 292 $ 54 $ 15,758 Six months ended June 30, June 30, Share-based compensation for non-vested shares $ 2,965 $ 2,518 Tax benefit for non-vested share compensation $ 741 $ 917 Unrecognized compensation cost for non-vested shares, net of estimated forfeitures $ 13,371 $ 8,826 Weighted average period over which unrecognized compensation will be recognized (years) 2.0
Key Employee Performance Share Based Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangements by Share-based Payment Award, Performance-Based Units, Vested and Expected to Vest [Table Text Block]	The fair value of the performance shares was estimated using a Monte Carlo simulation. The weighted average assumptions used in the Monte Carlo estimate were as follows: Six months ended June 30, June 30, Expected stock price volatility 24.3 % 24.7 % Weighted average risk-free interest rate 2.2 % 1.4 % The following tables summarize the Company’s employee performance share activity, assuming median share awards, and related information: Three months ended June 30, June 30, Share-based compensation for performance shares $ 307 $ 257 Six months ended June 30, 2018 Weighted- Aggregate Performance Average Grant Date Shares Grant Date Fair Value (000) Fair Value (000) Outstanding and non-vested at December 31, 2017 69 $ 58 Granted 18 72 Additional shares awarded based on performance — — Vested — — Forfeited (22 ) 67 Outstanding and non-vested at June 30, 2018 65 $ 58 $ 3,795 Six months ended June 30, June 30, Share-based compensation for performance shares $ 642 $ 441 Tax benefit for performance share compensation $ 161 $ 160 Unrecognized compensation cost for performance shares, net of estimated forfeitures $ 2,036 $ 2,135 Weighted average period over which unrecognized compensation will be recognized (years) 2.0
Nonemployee Director Nonvested Shares Granted Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block]	The following tables summarize the Company’s non-employee non-vested share activity and related information: Three months ended June 30, June 30, Share-based compensation for non-vested shares $ 166 $ 146 Six months ended June 30, 2018 Weighted- Aggregate Non-vested Average Grant Date Shares Grant Date Fair Value (000) Fair Value (000) Outstanding and non-vested at December 31, 2017 11 $ 52 Granted 15 58 Vested (12 ) 52 Forfeited — — Outstanding and non-vested at June 30, 2018 14 $ 58 $ 805 Six months ended June 30, June 30, Share-based compensation for non-vested shares $ 351 $ 317 Tax benefit for non-vested share compensation $ 88 $ 115 Unrecognized compensation cost for non-vested shares, net of estimated forfeitures $ 703 $ 442 Weighted average period over which unrecognized compensation will be recognized (years) 0.9

Net Income Per Share (Tables)

Net Income Per Share (Tables)	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
Net Income Per Share	The following table sets forth the computation of basic and diluted net income per share: Three months ended Six months ended June 30, June 30, June 30, June 30, (As Adjusted) (As Adjusted) Numerator: Net income and comprehensive income $ 24,298 $ 19,666 $ 42,038 $ 34,246 Income allocated to participating securities (209 ) (160 ) (359 ) (281 ) Numerator for basic and diluted income per share - net income $ 24,089 $ 19,506 $ 41,679 $ 33,965 Denominator (in thousands): Denominator for basic income per share - weighted-average shares 29,169 30,026 29,288 30,029 Effect of dilutive stock options (in thousands) 74 61 71 68 Effect of dilutive performance shares (in thousands) 29 27 32 30 Denominator for diluted income per share - adjusted weighted-average shares 29,272 30,114 29,391 30,127 Basic net income per share $ 0.83 $ 0.65 $ 1.42 $ 1.13 Diluted net income per share $ 0.82 $ 0.65 $ 1.42 $ 1.13 The number of instruments that could potentially dilute net income per basic share in the future, but that were not included in the computation of net income per diluted share because to do so would have been anti-dilutive for the periods presented, are as follows: June 30, June 30, Anti-dilutive stock options (in thousands) 82 284 Anti-dilutive performance shares (in thousands) 15 19 Anti-dilutive non-vested shares and deferred stock units (in thousands) 5 — Total anti-dilutive shares (in thousands) 102 303

Financial Instruments (Tables)

Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2018
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Financial Instruments	Using interest rate quotes and discounted cash flows, the Company estimated the fair value of its outstanding capital lease obligations as follows: June 30, 2018 Carrying Value Fair Value Capital leases $ 544 $ 565

Shareholders' Equity Shareholde

Shareholders' Equity Shareholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2018
Schedule of Stockholders Equity [Table Text Block]	On July 21, 2016, our Board of Directors approved a stock repurchase authorization for up to three million shares of the Company’s common stock. The following table summarizes our share repurchases for the three and six months ended June 30, 2018 and 2017. Three months ended Six months ended June 30, 2018 June 30, 2017 June 30, 2018 June 30, 2017 Shares repurchased 132,880 42,055 497,166 246,864 Cost of shares repurchased $ 8,172 $ 1,999 $ 28,165 $ 11,995 Average cost per share $ 61.50 $ 47.54 $ 56.65 $ 48.59

Segment Reporting (Tables)

Segment Reporting (Tables)	6 Months Ended
	Jun. 30, 2018
Segment Reporting [Abstract]
Summary of segment information	The following tables summarize segment information about results from operations and assets used by the chief operating decision maker of the Company in making decisions regarding allocation of assets and resources as of and for the three and six months ended June 30, 2018 and 2017. Three months ended June 30, 2018 Expedited LTL Truckload Premium Pool Distribution Intermodal Eliminations & other Consolidated External revenues $ 191,159 $ 46,903 $ 43,197 $ 49,084 $ — $ 330,343 Intersegment revenues 1,732 2,044 108 78 (3,962 ) — Depreciation and amortization 5,557 1,562 1,705 1,537 1 10,362 Share-based compensation expense 1,877 166 113 210 51 2,417 Interest expense — 2 — 24 457 483 Income from operations 26,526 1,717 1,589 5,543 (2,505 ) 32,870 Total assets 658,125 69,082 58,695 151,962 (226,572 ) 711,292 Capital expenditures 10,648 36 576 125 — 11,385 Three months ended June 30, 2017 (As Adjusted) Expedited LTL Truckload Premium Pool Distribution Intermodal Eliminations & other Consolidated External revenues $ 159,842 $ 49,129 $ 37,685 $ 37,220 $ — $ 283,876 Intersegment revenues 630 1,322 71 20 (2,043 ) — Depreciation and amortization 5,520 1,590 1,613 1,496 — 10,219 Share-based compensation expense 1,731 85 119 129 — 2,064 Interest expense 1 — — 13 222 236 Income (loss) from operations 23,047 1,855 1,625 3,209 260 29,996 Total assets 629,098 57,933 51,214 145,343 (219,320 ) 664,268 Capital expenditures 1,756 2 203 49 — 2,010 Six months ended June 30, 2018 Expedited LTL Truckload Premium Pool Distribution Intermodal Eliminations & other Consolidated External revenues $ 359,521 $ 90,064 $ 85,804 $ 97,562 $ — $ 632,951 Intersegment revenues 3,314 4,976 172 169 (8,631 ) — Depreciation and amortization 11,085 3,320 3,509 3,138 — 21,052 Share-based compensation expense 3,553 345 229 500 51 4,678 Interest expense 1 3 — 37 813 854 Income (loss) from operations 47,298 1,674 2,960 9,012 (3,839 ) 57,105 Total assets 658,125 69,082 58,695 151,962 (226,572 ) 711,292 Capital expenditures 16,705 40 654 207 — 17,606 Six months ended June 30, 2017 (As Adjusted) Expedited LTL Truckload Premium Pool Distribution Intermodal Eliminations & other Consolidated External revenues $ 308,021 $ 95,368 $ 76,416 $ 66,116 $ — $ 545,921 Intersegment revenues 1,216 2,170 142 31 (3,559 ) — Depreciation and amortization 11,084 3,147 3,415 2,606 — 20,252 Share-based compensation expense 3,377 180 207 262 — 4,026 Interest expense 2 — — 24 492 518 Income (loss) from operations 41,975 3,610 2,991 5,763 (601 ) 53,738 Total assets 629,098 57,933 51,214 145,343 (219,320 ) 664,268 Capital expenditures 4,267 8 286 101 — 4,662

Description of Business and B24

Description of Business and Basis of Presentation (Details)	6 Months Ended
	Jun. 30, 2018
Number of principal reporting segments	4

Recent Accounting Pronounceme25

Recent Accounting Pronouncements (Details) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)$ / shares	Jun. 30, 2017USD ($)$ / shares	Jun. 30, 2018USD ($)$ / shares	Jun. 30, 2017USD ($)$ / shares	Dec. 31, 2017USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts Receivable, Net, Current	$ 152,393		$ 152,393		$ 147,948
Number of principal reporting segments			4
Operating revenue	330,343	$ 283,876	$ 632,951	$ 545,921
Operating Income (Loss)	32,870	29,996	57,105	53,738
Income Tax Expense (Benefit)	8,088	10,112	14,212	18,966
Net income	$ 24,298	$ 19,666	$ 42,038	$ 34,246
Diluted (in dollars per share) | $ / shares	$ 0.82	$ 0.65	$ 1.42	$ 1.13
Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue		$ 283,876		$ 545,921
Operating Expenses		253,880		492,183
Operating Income (Loss)		29,996		53,738
Income Tax Expense (Benefit)		10,112		18,966
Net income		$ 19,666		$ 34,246
Diluted (in dollars per share) | $ / shares		$ 0.65		$ 1.13
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		$ 15,392		$ 29,595
Expedited LTL [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue	$ 191,159	159,842	$ 359,521	308,021
Operating Income (Loss)	26,526	23,047	47,298	41,975
Expedited LTL [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue		160,472		309,237
Truckload Premium Services [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue		50,451		97,538
Pool Distribution [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue	43,197	37,685	85,804	76,416
Operating Income (Loss)	1,589	1,625	2,960	2,991
Pool Distribution [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue		37,756		76,558
Intermodal [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue	49,084	37,220	97,562	66,116
Operating Income (Loss)	5,543	3,209	9,012	5,763
Intermodal [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue		37,240		66,147
Elimination [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Income (Loss)	$ (2,505)	260	$ (3,839)	(601)
Elimination [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue		(2,043)		(3,559)
Scenario, Previously Reported [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue		267,518		514,499
Operating Expenses		237,709		461,502
Operating Income (Loss)		29,809		52,997
Income Tax Expense (Benefit)		10,041		18,678
Net income		$ 19,550		$ 33,793
Diluted (in dollars per share) | $ / shares		$ 0.64		$ 1.11
Scenario, Previously Reported [Member] | Expedited LTL [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue		$ 152,270		$ 292,868
Scenario, Previously Reported [Member] | Truckload Premium Services [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue		45,186		86,971
Scenario, Previously Reported [Member] | Pool Distribution [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue		36,835		74,658
Scenario, Previously Reported [Member] | Intermodal [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue		35,270		63,561
Scenario, Previously Reported [Member] | Elimination [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue		(2,043)		(3,559)
Restatement Adjustment [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue		16,358		31,422
Operating Expenses		16,171		30,681
Operating Income (Loss)		187		741
Income Tax Expense (Benefit)		71		288
Net income		$ 116		$ 453
Diluted (in dollars per share) | $ / shares		$ 0.01		$ 0.02
Restatement Adjustment [Member] | Expedited LTL [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue		$ 8,202		$ 16,369
Restatement Adjustment [Member] | Truckload Premium Services [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue		5,265		10,567
Restatement Adjustment [Member] | Pool Distribution [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue		921		1,900
Restatement Adjustment [Member] | Intermodal [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue		1,970		2,586
Restatement Adjustment [Member] | Elimination [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating revenue		$ 0		$ 0

Acquisitions and Goodwill (Deta

Acquisitions and Goodwill (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017	Oct. 22, 2017	May 07, 2017
Segment Reporting Information [Line Items]
Business Acquisition, Goodwill, Expected Tax Deductible Amount	$ 112,527
Carrying value of goodwill	$ 191,671	$ 191,671
Number of Reporting Units	5
Atlantic [Member]
Segment Reporting Information [Line Items]
Business Acquisition, Cash Paid				$ 22,500
Business Combination, Contingent Consideration, Liability				1,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment				1,821
Business Combination, Recognized Identifiable Assets Acquired and Total Liabilities Assumed, Total Tangible Assets				1,821
Carrying value of goodwill				6,719
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles				21,269
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets				23,090
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities				590
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities				590
Business Combination, Recognized Identifiable Assets Acquired and Total Liabilities Assumed, Net Total Assets				22,500
Expedited LTL [Member]
Segment Reporting Information [Line Items]
Carrying value of goodwill	$ 97,593
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount	349.00%
Fair Value Inputs, Discount Rate	12.00%
Fair Value Inputs, Long-term Revenue Growth Rate	4.00%
Truckload Expedited [Member]
Segment Reporting Information [Line Items]
Goodwill, Impaired, Accumulated Impairment Loss	$ (25,686)
Carrying value of goodwill	45,164
Pool Distribution [Member]
Segment Reporting Information [Line Items]
Goodwill, Impaired, Accumulated Impairment Loss	(6,953)
Carrying value of goodwill	$ 12,359
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount	182.00%
Fair Value Inputs, Discount Rate	15.50%
Fair Value Inputs, Long-term Revenue Growth Rate	4.00%
Intermodal [Member]
Segment Reporting Information [Line Items]
Carrying value of goodwill	$ 69,194
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount	73.00%
Fair Value Inputs, Discount Rate	14.00%
Fair Value Inputs, Long-term Revenue Growth Rate	4.00%
TQI [Member]
Segment Reporting Information [Line Items]
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount	36.00%
Fair Value Inputs, Discount Rate	16.50%
Fair Value Inputs, Long-term Revenue Growth Rate	4.00%
KCL [Member]
Segment Reporting Information [Line Items]
Business Acquisition, Cash Paid			$ 640
Business Combination, Contingent Consideration, Liability			100
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment			223
Business Combination, Recognized Identifiable Assets Acquired and Total Liabilities Assumed, Total Tangible Assets			223
Carrying value of goodwill			277
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles			517
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets			740
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities			100
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities			100
Business Combination, Recognized Identifiable Assets Acquired and Total Liabilities Assumed, Net Total Assets			640
Noncompete Agreements [Member] | Atlantic [Member]
Segment Reporting Information [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	5 years
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill				1,150
Noncompete Agreements [Member] | KCL [Member]
Segment Reporting Information [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	2 years
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill			6
Customer Relationships [Member] | Atlantic [Member]
Segment Reporting Information [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	15 years
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill				$ 13,400
Customer Relationships [Member] | KCL [Member]
Segment Reporting Information [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	15 years
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill			$ 234

Share-Based Payments - Stock Op

Share-Based Payments - Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 2,417	$ 2,064	$ 4,678	$ 4,026
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option grants expire (in years)			7 years
Grants, vesting period (in years)			3 years
Expected dividend yield (in hundredths)			1.10%	1.30%
Expected stock price volatility			24.90%	28.70%
Weighted Average Risk Free Interest Rate			2.60%	2.00%
Expected life of options (in years)			6 years 11 days	6 years 11 days
Weighted-average fair value of options (dollars per share)			$ 15	$ 13
Outstanding, beginning of period (in shares)			440
Granted (in shares)			86
Exercised (in shares)			(26)
Forfeited (in shares)			0
Outstanding, end of period (in shares)	500		500
Exercisable, end of period (in shares)	287		287
Outstanding, beginning of period (in dollars per share)			$ 45
Grants in Period (in dollars per share)			59
Exercises in Period (in dollars per share)			42
Forfeited in period (in dollars per share)			0
Outstanding, end of period (in dollars per share)	$ 47		47
Exercisable, end of period (in dollars per share)	$ 44		$ 44
Aggregate Intrinsic Value Outstanding, end of period	$ 4,985		$ 4,985
Aggregate Intrinsic Value Exercisable, end of period	3,853		$ 3,853
Weighted-average remaining contractual term Outstanding, end of period (in years)			4 years 4 months 11 days
Weighted-average remaining contractual term Exercisable, end of period (in years)			3 years 3 months 11 days
Share-based compensation expense	346	331	$ 688	$ 699
Tax benefit related to share-based expense			172	254
Unrecognized share-based compensation, net of estimated forfeitures	$ 2,243	$ 2,281	$ 2,243	$ 2,281
Weighted average period over which unrecognized compensation will be recognized (years)			2 years 11 days

Share-Based Payments - Employee

Share-Based Payments - Employee Activity Non-vested Shares (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 2,417	$ 2,064	$ 4,678	$ 4,026
Employee Non-vested Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants, vesting period (in years)			3 years
Outstanding and non-vested, beginning of period (in shares)			227
Stock Issued During Period, Shares, Restricted Stock Award, Gross			174
Shares Vested in Period			(107)
Shares Forfeited in Period			(2)
Outstanding and non-vested, end of period (in shares)	292		292
Outstanding and non-vested, weighted-average grant date fair value, beginning of period			$ 47
Grants in Period, Weighted Average Grant Date Fair Value			59
Vested in Period, Weighed-average grant date fair value			56
Forfeited in period (in dollars per share)			52
Outstanding and non-vested, weighted-average grant date fair value, end of period	$ 54		$ 54
Outstanding and non-vested, aggregate grant date fair value			$ 15,758
Share-based compensation expense	$ 1,566	1,279	2,965	2,518
Tax benefit related to share-based expense			741	917
Unrecognized share-based compensation, net of estimated forfeitures	$ 13,371	$ 8,826	$ 13,371	$ 8,826
Weighted average period over which unrecognized compensation will be recognized (years)			2 years 11 days

Share-Based Payments - Employ29

Share-Based Payments - Employee Activity Performance Shares (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 2,417	$ 2,064	$ 4,678	$ 4,026
Key Employee Performance Share Based Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period of Share Price Performance Comparison to Peer Group			3 years
Minimum percentage of peer group by which Company share price must outperform before incremental performance shares are issued			25.00%
Percentage of Peer Group By Which Company Share Price Must Outperform Before Maximum Incremental Shares Are Issued			90.00%
Expected Stock Price Volatility Rate			24.30%	24.70%
Weighted Average Risk Free Interest Rate			2.20%	1.40%
Outstanding and non-vested, beginning of period (in shares)			69
Grants in Period			18
Shares Forfeited in Period			(22)
Outstanding and non-vested, end of period (in shares)	65		65
Outstanding and non-vested, weighted-average grant date fair value, beginning of period			$ 58
Grants in Period, Weighted Average Grant Date Fair Value			72
Forfeited in Period, Weighted Average Grant Date Fair Value			67
Outstanding and non-vested, weighted-average grant date fair value, end of period	$ 58		$ 58
Outstanding and non-vested, aggregate grant date fair value			$ 3,795
Share-based compensation expense	$ 307	257	642	$ 441
Tax benefit related to share-based expense			161	160
Unrecognized share-based compensation, net of estimated forfeitures	$ 2,036	$ 2,135	$ 2,036	$ 2,135
Weighted average period over which unrecognized compensation will be recognized (years)			2 years 11 days

Share-Based Payments Share-Base

Share-Based Payments Share-Based Payments - Employee Stock Purchase Plan (Details) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)$ / sharesshares	Jun. 30, 2017USD ($)$ / shares	Jun. 30, 2018USD ($)$ / sharesshares	Jun. 30, 2017USD ($)$ / sharesshares
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Share-based compensation expense | $	$ 2,417	$ 2,064	$ 4,678	$ 4,026
Employee Stock Purchase Plan [Member]
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) | shares	367,309		367,309
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Purchase Date			90.00%
Number of Large Lump Sum Contributions Related to ESPP Stock Purchases	2		2
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares) | shares			4,550	5,188
Share-based Compensation Arrangement by Share-based Payment Award, Per Share Weighted Average Price of Shares Purchased (in dollars per share) | $ / shares	$ 51.98	$ 43.59	$ 51.98	$ 43.59
Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share) | $ / shares			$ 7.10	$ 9.69
Share-based compensation expense | $			$ 32	$ 51

Share-Based Payments - Non-empl

Share-Based Payments - Non-employee Director Non-vested Shares (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 2,417	$ 2,064	$ 4,678	$ 4,026
Nonemployee Director Nonvested Shares Granted Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-Employee Director Shares, Vesting Period (in years)			1 year
Outstanding and non-vested, beginning of period (in shares)			11
Grants in Period			15
Shares Vested in Period			(12)
Shares Forfeited in Period			0
Outstanding and non-vested, end of period (in shares)	14		14
Outstanding and non-vested, weighted-average grant date fair value, beginning of period			$ 52
Grants in Period, Weighted Average Grant Date Fair Value			58
Vested in Period, Weighed-average grant date fair value			52
Forfeited in Period, Weighted Average Grant Date Fair Value			0
Outstanding and non-vested, weighted-average grant date fair value, end of period	$ 58		$ 58
Outstanding and non-vested, aggregate grant date fair value			$ 805
Share-based compensation expense	$ 166	146	351	317
Tax benefit related to share-based expense			88	115
Unrecognized share-based compensation, net of estimated forfeitures	$ 703	$ 442	$ 703	$ 442
Weighted average period over which unrecognized compensation will be recognized (years)			10 months 11 days

Senior Credit Facility (Details

Senior Credit Facility (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Sep. 29, 2017
Debt Instrument [Line Items]
Proceeds from senior credit facility	$ 0	$ 35,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility Term, In Years			5
Line of Credit Facility, Current Borrowing Capacity			$ 150,000
Additional borrowing capacity of credit facility			100,000
Credit facility amount			$ 250,000
Base reference rate of credit facilities	LIBOR
Interest rate spread above LIBOR as of reporting period (in hundredths)	1.00%
Debt Instrument, Basis Spread on Variable Rate, Minimum			0.30%
Debt Instrument, Basis Spread on Variable Rate, Maximum			0.80%
Proceeds from senior credit facility	$ 40,500
Available borrowing capacity	$ 98,461
Line of Credit Facility, Interest Rate at Period End	3.60%
Letter of Credit [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Capacity Available for Specific Purpose Other than for Trade Purchases			$ 30,000
Letters of Credit Outstanding, Amount	$ 11,039
Swing line loan [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Capacity Available for Specific Purpose Other than for Trade Purchases			$ 30,000
Federal funds [Member]
Debt Instrument [Line Items]
Interest rate spread above LIBOR as of reporting period (in hundredths)	0.50%

Net Income Per Share (Details)

Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Earnings Per Share, Basic, Two Class Method [Abstract]
Net income and comprehensive income	$ 24,298	$ 19,666	$ 42,038	$ 34,246
Income allocated to participating securities	(209)	(160)	(359)	(281)
Numerator for basic and diluted income per share - net income	$ 24,089	$ 19,506	$ 41,679	$ 33,965
Denominator for basic income per share - weighted-average shares	29,169	30,026	29,288	30,029
Denominator for diluted income per share - adjusted weighted-average shares	29,272	30,114	29,391	30,127
Basic income per share (dollars per share)	$ 0.83	$ 0.65	$ 1.42	$ 1.13
Diluted income per share (dollars per share)	$ 0.82	$ 0.65	$ 1.42	$ 1.13
Total number anti-dilutive options, non-vested shares, and performance shares excluded from income per diluted share computation			102	303
Equity Option [Member]
Earnings Per Share, Basic, Two Class Method [Abstract]
Effect of dilutive stock options and non-vested shares	74	61	71	68
Total number anti-dilutive options, non-vested shares, and performance shares excluded from income per diluted share computation			82	284
Key Employee Performance Share Based Plan [Member]
Earnings Per Share, Basic, Two Class Method [Abstract]
Effect of dilutive stock options and non-vested shares	29	27	32	30
Total number anti-dilutive options, non-vested shares, and performance shares excluded from income per diluted share computation			15	19
Nonvested Shares and Deferred Stock Units [Member]
Earnings Per Share, Basic, Two Class Method [Abstract]
Total number anti-dilutive options, non-vested shares, and performance shares excluded from income per diluted share computation			5	0

Income Taxes (Details)

Income Taxes (Details)	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Effective statutory federal income tax rate	21.00%	35.00%
Effective Income Tax Rate, Continuing Operations	25.30%	35.60%

Financial Instruments - Fair Va

Financial Instruments - Fair Value (Details) $ in Thousands	Jun. 30, 2018USD ($)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other debt and capital leases	$ 565
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other debt and capital leases	$ 544

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($)	3 Months Ended						6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Jul. 21, 2016
Shareholders' Equity [Line Items]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased									3,000,000
Stock Repurchased and Retired During Period, Shares	132,880				42,055		497,166	246,864
Stock Repurchased and Retired During Period, In Total Dollars	$ 8,172,000				$ 1,999,000		$ 28,165,000	$ 11,995,000
Stock repurchased, common stock acquired, average cost per share	$ 61.50				$ 47.54		$ 56.65	$ 48.59
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	1,321,499						1,321,499
Common Stock [Member]
Shareholders' Equity [Line Items]
Dividends per share (in dollars per share)	$ 0.15	$ 0.15	$ 0.15	$ 0.15	$ 0.15	$ 0.15	$ 0.30	$ 0.30

Segment Reporting (Details)

Segment Reporting (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Segment Reporting Information [Line Items]
External revenues	$ 330,343	$ 283,876	$ 632,951	$ 545,921
Depreciation and amortization	10,362	10,219	21,052	20,252
Share-based compensation expense	2,417	2,064	4,678	4,026
Interest expense	483	236	854	518
Operating Income (Loss)	32,870	29,996	57,105	53,738
Total assets	711,292	664,268	711,292	664,268	$ 692,622
Capital expenditures	11,385	2,010	$ 17,606	4,662
Number of reportable segments			4
Expedited LTL [Member]
Segment Reporting Information [Line Items]
External revenues	191,159	159,842	$ 359,521	308,021
Intersegment revenues	1,732	630	3,314	1,216
Depreciation and amortization	5,557	5,520	11,085	11,084
Share-based compensation expense	1,877	1,731	3,553	3,377
Interest expense		1	1	2
Operating Income (Loss)	26,526	23,047	47,298	41,975
Total assets	658,125	629,098	658,125	629,098
Capital expenditures	10,648	1,756	16,705	4,267
Truckload Expedited [Member]
Segment Reporting Information [Line Items]
External revenues	46,903	49,129	90,064	95,368
Intersegment revenues	2,044	1,322	4,976	2,170
Depreciation and amortization	1,562	1,590	3,320	3,147
Share-based compensation expense	166	85	345	180
Interest expense	2		3
Operating Income (Loss)	1,717	1,855	1,674	3,610
Total assets	69,082	57,933	69,082	57,933
Capital expenditures	36	2	40	8
Pool Distribution [Member]
Segment Reporting Information [Line Items]
External revenues	43,197	37,685	85,804	76,416
Intersegment revenues	108	71	172	142
Depreciation and amortization	1,705	1,613	3,509	3,415
Share-based compensation expense	113	119	229	207
Operating Income (Loss)	1,589	1,625	2,960	2,991
Total assets	58,695	51,214	58,695	51,214
Capital expenditures	576	203	654	286
Intermodal [Member]
Segment Reporting Information [Line Items]
External revenues	49,084	37,220	97,562	66,116
Intersegment revenues	78	20	169	31
Depreciation and amortization	1,537	1,496	3,138	2,606
Share-based compensation expense	210	129	500	262
Interest expense	24	13	37	24
Operating Income (Loss)	5,543	3,209	9,012	5,763
Total assets	151,962	145,343	151,962	145,343
Capital expenditures	125	49	207	101
Elimination [Member]
Segment Reporting Information [Line Items]
Intersegment revenues	(3,962)	(2,043)	(8,631)	(3,559)
Depreciation and amortization	1
Share-based compensation expense	51		51
Interest expense	457	222	813	492
Operating Income (Loss)	(2,505)	260	(3,839)	(601)
Total assets	$ (226,572)	$ (219,320)	$ (226,572)	$ (219,320)