Echo Global Logistics 10-Q 25 Jul 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Jul. 24, 2019
Document and Entity Information [Abstract]
Document Transition Report	false
Document Quarterly Report	true
Title of 12(b) Security	Common stock, par value $0.0001 per share
Entity Incorporation, State or Country Code	DE
Trading Symbol	ECHO
Entity Registrant Name	ECHO GLOBAL LOGISTICS, INC.
Entity Central Index Key	0001426945
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2019
Entity File Number	001-34470
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		27,282,367
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Tax Identification Number	20-5001120
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Address, Address Line One	600 West Chicago Avenue
Entity Address, Address Line Two	Suite 725
Entity Address, City or Town	Chicago
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60654
City Area Code	800
Local Phone Number	354-7993

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Revenue	$ 553,775	$ 634,811	$ 1,091,858	$ 1,211,902
Costs and expenses:
Transportation costs	453,173	528,022	892,489	1,005,190
Selling, general and administrative expenses	80,138	84,644	160,333	165,162
Depreciation and amortization	9,793	9,033	19,261	17,939
Income from operations	10,672	13,112	19,775	23,612
Interest expense	(3,555)	(3,754)	(6,968)	(7,504)
Income before provision for income taxes	7,117	9,358	12,807	16,107
Income tax expense	(2,050)	(1,680)	(4,244)	(3,702)
Net income	$ 5,067	$ 7,678	$ 8,564	$ 12,405
Earnings per common share:
Basic (in usd per share)	$ 0.19	$ 0.28	$ 0.32	$ 0.45
Diluted (in usd per share)	$ 0.19	$ 0.28	$ 0.32	$ 0.45

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 16,022	$ 40,281
Accounts receivable, net of allowance for doubtful accounts of $3,981 and $4,618 at June 30, 2019 and December 31, 2018, respectively	321,680	337,426
Income taxes receivable	665	2,805
Prepaid expenses	8,196	9,048
Other current assets	3,173	4,172
Total current assets	349,737	393,732
Noncurrent assets:
Property and equipment, net of accumulated depreciation of $123,054 and $110,010 at June 30, 2019 and December 31, 2018, respectively	61,291	61,955
Goodwill	309,589	309,589
Intangible assets, net of accumulated amortization of $76,053 and $69,855 at June 30, 2019 and December 31, 2018, respectively	103,365	109,563
Operating lease assets	19,852	0
Other noncurrent assets	4,210	3,485
Total noncurrent assets	498,307	484,593
Total assets	848,044	878,325
Current liabilities:
Accounts payable	220,035	216,280
Due to seller, current	950	2,243
Accrued expenses	35,461	48,129
Other current liabilities	5,704	255
Total current liabilities	262,151	266,907
Noncurrent liabilities:
Convertible notes, net	153,381	183,168
Due to seller, noncurrent	1,150	717
Other noncurrent liabilities	533	18,369
Deferred income taxes	21,926	19,233
Noncurrent operating lease liabilities	33,174	0
Total noncurrent liabilities	210,164	221,487
Total liabilities	472,316	488,394
Stockholders' equity:
Common stock, par value $0.0001 per share, 100,000,000 shares authorized, 31,498,159 shares issued and 26,396,576 shares outstanding at June 30, 2019; 31,345,220 shares issued and 27,397,760 shares outstanding at December 31, 2018	3	3
Treasury stock, 5,101,583 and 3,947,460 shares at June 30, 2019 and December 31, 2018, respectively	(105,679)	(79,571)
Additional paid-in capital	351,739	348,397
Retained earnings	129,666	121,102
Total stockholders' equity	375,729	389,932
Total liabilities and stockholders' equity	$ 848,044	$ 878,325

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Allowance for doubtful accounts	$ 3,981	$ 4,618
Noncurrent assets:
Property and equipment, accumulated depreciation	123,054	110,010
Customer relationships and other intangible assets, accumulated amortization	$ 76,053	$ 69,855
Stockholders' equity:
Common stock, par value (in usd per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	31,498,159	31,345,220
Common stock, shares outstanding (in shares)	26,396,576	27,397,760
Treasury stock, shares (in shares)	5,101,583	3,947,460

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Operating activities
Net income	$ 8,564	$ 12,405
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income taxes	2,788	2,943
Noncash stock compensation expense	5,230	4,737
Noncash interest expense	4,202	4,211
Change in contingent consideration due to seller	490	100
Depreciation and amortization	19,261	17,939
Change in assets:
Accounts receivable	15,778	(71,543)
Income taxes receivable	2,328	745
Prepaid expenses and other assets	900	(3,407)
Change in liabilities:
Accounts payable	3,785	63,517
Accrued expenses and other liabilities	(11,023)	3,409
Payments of contingent consideration in excess of costs over estimated earnings	(1,097)	(375)
Net cash provided by operating activities	51,206	34,680
Investing activities
Purchases of property and equipment	(13,166)	(13,231)
Investments in business entities	0	(1,000)
Payments for acquisitions, net of cash acquired	(33)	0
Net cash used in investing activities	(13,198)	(14,231)
Financing activities
Payments of contingent consideration due to seller	(253)	(550)
Proceeds from exercise of stock options	37	3,561
Employee tax withholdings related to net share settlements of equity-based awards	(2,027)	(2,318)
Purchases of treasury stock	(26,108)	0
Purchases of Convertible Notes	(33,915)	0
Proceeds from borrowing on ABL facility	15,000	12,000
Repayments of amounts borrowed on ABL facility	(15,000)	(12,000)
Net cash (used in) provided by financing activities	(62,266)	693
(Decrease) Increase in cash and cash equivalents	(24,259)	21,141
Cash and cash equivalents, beginning of period	40,281	23,515
Cash and cash equivalents, end of period	16,022	44,656
Supplemental disclosure of cash flow information
Cash paid during the period for interest	2,904	3,282
Cash paid during the period for income taxes	2,476	144
Cash received during the period for income taxes refunded	$ 3,348	$ 129

Consolidated Statement of Stock

Consolidated Statement of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-In Capital	Retained Earnings
Stockholders' equity at beginning of period at Dec. 31, 2017	$ 358,872	$ 3	$ (69,818)	$ 337,445	$ 91,242
Shares at beginning of period (in shares) at Dec. 31, 2017		30,768,050	(3,526,870)
Increase in stockholders' equity:
Share compensation expense	2,350			2,350
Exercise of stock options	1,239	$ 0		1,239
Exercise of stock options (in shares)		123,442
Common stock issued for vested restricted stock	0	$ 0		0
Common stock issued for vested restricted stock (in shares)		195,853
Common stock issued for vested performance shares	0	$ 0		0
Common stock issued for vested performance shares (in shares)		26,567
Common shares withheld and retired to satisfy employee tax withholding obligations upon vesting of restricted stock	(2,222)	$ 0		(2,222)
Common shares withheld and retired to satisfy employee tax withholding obligations upon vesting of restricted stock (in shares)		(78,812)
Net income	4,727				4,727
Stockholders' equity at end of period at Mar. 31, 2018	366,101	$ 3	$ (69,818)	338,811	97,105
Shares at end of period (in shares) at Mar. 31, 2018		31,035,100	(3,526,870)
Stockholders' equity at beginning of period at Dec. 31, 2017	358,872	$ 3	$ (69,818)	337,445	91,242
Shares at beginning of period (in shares) at Dec. 31, 2017		30,768,050	(3,526,870)
Increase in stockholders' equity:
Net income	12,405
Stockholders' equity at end of period at Jun. 30, 2018	378,218	$ 3	$ (69,818)	343,249	104,783
Shares at end of period (in shares) at Jun. 30, 2018		31,243,465	(3,526,870)
Stockholders' equity at beginning of period at Mar. 31, 2018	366,101	$ 3	$ (69,818)	338,811	97,105
Shares at beginning of period (in shares) at Mar. 31, 2018		31,035,100	(3,526,870)
Increase in stockholders' equity:
Share compensation expense	2,212			2,212
Exercise of stock options	2,322	$ 0		2,322
Exercise of stock options (in shares)		201,900
Common stock issued for vested restricted stock	0	$ 0		0
Common stock issued for vested restricted stock (in shares)		9,870
Common shares withheld and retired to satisfy employee tax withholding obligations upon vesting of restricted stock	(96)	$ 0		(96)
Common shares withheld and retired to satisfy employee tax withholding obligations upon vesting of restricted stock (in shares)		(3,405)
Net income	7,678				7,678
Stockholders' equity at end of period at Jun. 30, 2018	378,218	$ 3	$ (69,818)	343,249	104,783
Shares at end of period (in shares) at Jun. 30, 2018		31,243,465	(3,526,870)
Stockholders' equity at beginning of period at Dec. 31, 2018	389,932	$ 3	$ (79,571)	348,397	121,102
Shares at beginning of period (in shares) at Dec. 31, 2018		31,345,220	(3,947,460)
Increase in stockholders' equity:
Share compensation expense	2,806			2,806
Exercise of stock options	37	$ 0		37
Exercise of stock options (in shares)		3,000
Common stock issued for vested restricted stock	0	$ 0		0
Common stock issued for vested restricted stock (in shares)		215,071
Common stock issued for vested performance shares	0	$ 0		0
Common stock issued for vested performance shares (in shares)		13,267
Common shares withheld and retired to satisfy employee tax withholding obligations upon vesting of restricted stock	(1,978)	$ 0		(1,978)
Common shares withheld and retired to satisfy employee tax withholding obligations upon vesting of restricted stock (in shares)		(81,936)
Repurchase of convertible notes, net of deferred taxes	36			36
Purchases of treasury stock	(10,629)		$ (10,629)
Purchase of treasury stock (in shares)			(452,350)
Net income	3,497				3,497
Stockholders' equity at end of period at Mar. 31, 2019	383,700	$ 3	$ (90,199)	349,298	124,599
Shares at end of period (in shares) at Mar. 31, 2019		31,494,622	(4,399,810)
Stockholders' equity at beginning of period at Dec. 31, 2018	389,932	$ 3	$ (79,571)	348,397	121,102
Shares at beginning of period (in shares) at Dec. 31, 2018		31,345,220	(3,947,460)
Increase in stockholders' equity:
Net income	8,564
Stockholders' equity at end of period at Jun. 30, 2019	375,729	$ 3	$ (105,679)	351,739	129,666
Shares at end of period (in shares) at Jun. 30, 2019		31,498,159	(5,101,583)
Stockholders' equity at beginning of period at Mar. 31, 2019	383,700	$ 3	$ (90,199)	349,298	124,599
Shares at beginning of period (in shares) at Mar. 31, 2019		31,494,622	(4,399,810)
Increase in stockholders' equity:
Share compensation expense	2,425			2,425
Common stock issued for vested restricted stock	0	$ 0		0
Common stock issued for vested restricted stock (in shares)		5,789
Common shares withheld and retired to satisfy employee tax withholding obligations upon vesting of restricted stock	(49)	$ 0		(49)
Common shares withheld and retired to satisfy employee tax withholding obligations upon vesting of restricted stock (in shares)		(2,252)
Repurchase of convertible notes, net of deferred taxes	66			66
Purchases of treasury stock	(15,480)		$ (15,480)
Purchase of treasury stock (in shares)			(701,773)
Net income	5,067				5,067
Stockholders' equity at end of period at Jun. 30, 2019	$ 375,729	$ 3	$ (105,679)	$ 351,739	$ 129,666
Shares at end of period (in shares) at Jun. 30, 2019		31,498,159	(5,101,583)

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The consolidated financial statements include the accounts of Echo Global Logistics, Inc. and its subsidiaries (the "Company" or "Echo"). All significant intercompany accounts and transactions have been eliminated in the consolidation. The consolidated statements of operations include the results of entities or assets acquired from the effective date of the acquisition for accounting purposes. The preparation of the consolidated financial statements is in conformity with the rules and regulations of the Securities and Exchange Commission ("SEC") and accounting principles generally accepted in the United States ("U.S. GAAP") for interim financial information. Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules or regulations. In the opinion of management, the accompanying unaudited financial statements reflect all adjustments considered necessary for a fair presentation of the results for the period and those adjustments are of a normal recurring nature. The operating results for the six months ended June 30, 2019 are not necessarily indicative of the results expected for the full year 2019 . These interim consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Company's audited financial statements for the year ended December 31, 2018 . Preparation of Financial Statements and Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenue and expenses during the reporting periods. Actual results can differ from those estimates. Fair Value of Financial Instruments The carrying values of the Company's financial instruments, which consist of cash and cash equivalents, accounts receivable and accounts payable, approximate their fair values due to their short-term nature. The fair value of the acquired intangible assets was determined using a discounted cash flow analysis as further described in Note 3. The fair value of the due to seller liabilities are determined based on the likelihood of the Company making contingent earn-out payments (see Note 5). The fair value of the liability component of the Notes (as defined in Note 12) was determined using the discounted cash flow analysis discussed in Note 12.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Jun. 30, 2019
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements Recently adopted accounting pronouncements In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2016-02, Leases, requiring a lessee to record, on the balance sheet, the assets and liabilities for the right-of-use assets and lease obligations created by leases with lease terms of more than 12 months. In July 2018, the FASB issued ASU 2018-11, which added amendments to create an optional transition method that provided an option to use the effective date of Accounting Standards Codification ("ASC") 842, Leases ("ASC Topic 842"), as the date of initial application of the transition. In addition, the new standard requires enhanced qualitative and quantitative disclosures related to the amount, timing and uncertainty of cash flows arising from leases. The Company adopted this standard on January 1, 2019 using the modified retrospective approach. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. Upon adoption, the Company elected the package of practical expedients that allows it to (i) not reassess whether an arrangement contains a lease, (ii) carry forward its lease classification as operating or capital leases and (iii) not reassess its previously recorded initial direct costs. In addition, the Company elected the practical expedient to not separate lease and non-lease components whereby both components are accounted for and recognized as lease components. The adoption resulted in a lease asset of $21.0 million and lease liability of $41.2 million , respectively, as of January 1, 2019. The Company's previous liability for deferred rent of $20.3 million was offset against the right of use asset upon adoption of the new standard. The standard did not impact the Company's consolidated statement of operations and had no impact on cash flows. The Company fully describes the adoption and impact of this standard in Note 13. As part of the adoption of this standard, the Company implemented changes to its accounting policies, practices and internal controls over financial reporting. In June 2018, the FASB issued ASU 2018-07, Compensation - Stock Compensation , which expands the scope of Topic 718 to include all share-based payment transactions for acquiring goods and services from nonemployees. The amendments in this update are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, with early adoption permitted. The Company's current share-based payment awards to non-employees consist only of grants made to its non-employee Directors as compensation solely relates to each individual's role as a non-employee Director. As such, in accordance with ASC 718, the Company accounts for these share-based payment awards to its non-employee Directors in the same manner as share-based payment awards for its employees. The Company adopted this standard on January 1, 2019, and the amendments in this guidance had no effect on the accounting for its share-based payment awards to its non-employee Directors, and had no effect on the consolidated financial statements. Recently issued accounting pronouncements not yet adopted In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement , which modifies the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement. This new accounting standard will be effective for annual periods beginning after December 15, 2019. Early adoption is permitted. The Company is evaluating the effects that the adoption of this guidance will have on its disclosures. In January 2017, the FASB issued ASU 2017-04, Intangibles - Goodwill and Other: Simplifying the Test for Goodwill Impairment , to simplify the subsequent measurement of goodwill by eliminating Step 2 from the goodwill impairment test. This new accounting standard will be effective for annual periods beginning after December 15, 2019. Early adoption is permitted. The Company is evaluating the effects that the adoption of this guidance will have on its consolidated financial statements. In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326) , which replaces the incurred loss methodology previously employed to measure credit losses for most financial assets and requires the use of a forward-looking expected loss model. Current accounting delays the recognition of credit losses until it is probable a loss has been incurred, while the update will require financial assets to be measured at amortized costs less a reserve and equal to the net amount expected to be collected. This standard will be effective for annual periods beginning after December 15, 2019, including interim periods within those fiscal years, with early adoption permitted. The Company is evaluating the effects that the adoption of this guidance will have on its consolidated financial statements.

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 2019
Business Combinations [Abstract]
Acquisitions	Acquisitions On July 6, 2018, the Company acquired Freight Management Plus, Inc. ("Freight Management," or "FMP"), a non-asset based truckload and less than truckload transportation brokerage based in Allison Park, Pennsylvania, and the results of FMP have been included in the Company's consolidated financial statements since the acquisition date. The Company purchased the assets and assumed certain liabilities of FMP for $6.7 million in cash payable at closing, $0.7 million of common stock, par value $0.0001 per share, and an additional $2.9 million in contingent consideration that may become payable upon the achievement of certain performance measures on or prior to June 30, 2021. The acquisition date fair value of the total consideration transferred was $10.5 million . The Company recorded $2.3 million of goodwill, $1.4 million as the estimated opening balance sheet fair value of the contingent consideration obligation, and $5.1 million of customer relationship intangible assets. The fair values of the contingent consideration obligation and the customer relationship intangible assets are considered Level 3 fair value estimates. The fair value of the contingent consideration obligation was based on the probability of reaching the financial forecasts of future operating results, an appropriate discount rate, and the Company's historical experience with similar arrangements as further described in Note 5. The fair value of the customer relationship intangible assets was determined using a discounted cash flow analysis based on the current customers of FMP at the time of the acquisition. The amount of goodwill deductible for U.S. income tax purposes is $0.9 million , which excludes the opening balance sheet fair value of the contingent consideration obligation. As of June 30, 2019, the fair value of the contingent consideration has increased to $2.1 million from its opening balance sheet fair value of $1.4 million . The Company will continue to reassess the fair value of the contingent consideration obligation each quarter.

Revenue

Revenue	6 Months Ended
	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue	Revenue Adoption of ASC Topic 606, "Revenue from Contracts with Customers" On January 1, 2018, the Company adopted ASU 2014-09, Revenue from Contracts with Customers ("ASC Topic 606"), using the modified retrospective method. The Company recorded an increase to the opening balance of retained earnings of $1.1 million , net of tax, as of January 1, 2018 due to the cumulative impact of adoption of ASC Topic 606. Revenue Recognition Revenue is recognized when control of the promised goods or services is transferred to our customers, in an amount that reflects the consideration the Company expects to receive in exchange for its services. The Company generates revenue from two different client types: Transactional and Managed Transportation. Most clients are categorized as Transactional clients. For its Transactional business, the Company provides brokerage and transportation management services on a shipment-by-shipment basis. Carrier selection, dispatch, load management and tracking are integrated services that occur within the brokerage and transportation management performance obligation. For the brokerage and transportation management services performance obligation, revenue is recognized as the client's shipment travels from origin to destination by a third-party carrier. The Company is the principal in these transactions and recognizes revenue on a gross and relative transit time basis. The Company categorizes a client as a Managed Transportation client if there is an agreement with the client for the provision of services, typically for a multi-year term. Brokerage and transportation management services is typically the performance obligation for the Company's Managed Transportation clients. Other performance obligations for Managed Transportation clients may include transportation management services, which includes the integrated services of dispatch, tracking and carrier payment. For these types of transactions, revenue is recorded on a net basis as the Company does not have latitude in carrier selection or establish rates with the carrier. The Company also performs project-based services, such as compliance management, customized re-billing services and freight studies for certain Managed Transportation clients. The following table presents the Company's revenue disaggregated by client type (in thousands): Three Months Ended June 30, Six Months Ended Client Type 2019 2018 2019 2018 Transactional $ 428,224 $ 502,788 $ 840,369 $ 955,897 Managed Transportation 125,551 132,023 251,490 256,005 Revenue $ 553,775 $ 634,811 $ 1,091,858 $ 1,211,902 Note: Amounts may not foot due to rounding. Revenue recognized per shipment varies depending on the transportation mode. The primary modes of shipment in which the Company transacts are truckload and less than truckload. Other transportation modes include intermodal, small parcel, domestic air, expedited and international. The following table presents the Company's revenue disaggregated by mode (in thousands): Three Months Ended June 30, Six Months Ended Mode 2019 2018 2019 2018 Truckload $ 362,254 $ 443,711 $ 716,572 $ 844,186 Less than truckload 165,046 160,584 319,985 307,818 Other revenue 26,476 30,516 55,301 59,898 Revenue $ 553,775 $ 634,811 $ 1,091,858 $ 1,211,902 Note: Amounts may not foot due to rounding. Variable Consideration Certain customers may receive rebates based on the terms of their agreement with the Company, which are accounted for as variable consideration. Rebates are estimated based on the expected amount to be provided to customers and reduce revenue recognized. The Company also estimates for possible additional fees based on a portfolio approach. Practical Expedients The Company adopted the practical expedient to recognize commission expense when incurred because the amortization period is less than one year. Commission expense recognition aligns with the Company's revenue recognition policy under ASC Topic 606, as commission expense is recognized on a relative transit time basis. The Company applied the disclosure exemption in ASC Topic 606 that permits the omission of remaining performance obligations that have an original expected duration of one year or less.

Fair Value Measurement

Fair Value Measurement	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurement	Fair Value Measurement The Company applies ASC Topic 820, Fair Value Measurements and Disclosures ("ASC Topic 820"), for its financial assets and financial liabilities. The guidance requires disclosures about assets and liabilities measured at fair value. The Company's financial liabilities primarily relate to contingent earn-out payments due to sellers in connection with various acquisitions. The fair value of the due to seller liabilities at June 30, 2019 and December 31, 2018 was $2.1 million and $3.0 million , respectively. The potential earn-out payments and performance periods are defined in the individual purchase agreements for each acquisition. Earnings before interest, taxes, depreciation and amortization ("EBITDA") is the performance target defined and measured to determine the earn-out payment due, if any, after each defined measurement period. ASC Topic 820 includes a fair value hierarchy that is intended to increase consistency and comparability in fair value measurements and related disclosures. The fair value hierarchy is based on observable or unobservable inputs to valuation techniques that are used to measure fair value. Observable inputs reflect assumptions market participants would use in pricing an asset or liability based on market data obtained from independent sources while unobservable inputs reflect a reporting entity's pricing based upon its own market assumptions. The fair value hierarchy consists of the following three levels: • Level 1: Inputs are quoted prices in active markets for identical assets or liabilities. • Level 2: Inputs are quoted prices for similar assets or liabilities in an active market, quoted prices for identical or similar assets or liabilities in markets that are not active, and inputs other than quoted prices that are observable and market-corroborated inputs, which are derived principally from or corroborated by observable market data. • Level 3: Inputs that are derived from valuation techniques in which one or more significant inputs or value drivers are unobservable. The significant inputs used to derive the fair value of the amounts due to seller include financial forecasts of future operating results, the probability of reaching the forecast and an appropriate discount rate for each contingent liability. Probabilities are estimated by reviewing financial forecasts and assessing the likelihood of reaching the required performance measures based on factors specific to each acquisition as well as the Company’s historical experience with similar arrangements. If an acquisition reaches the required performance measure, the estimated probability would be increased to 100% and would still be classified as a contingent liability on the balance sheet. If the measure is not reached, the probability would be reduced to reflect the amount earned, if any, depending on the terms of the agreement. Discount rates used in determining the fair value of the contingent consideration due to seller ranged from 5% to 7% . Historical results of the respective acquisitions serve as the basis for the financial forecasts used in the valuation. Quantitative factors are also considered in these forecasts, including acquisition synergies, growth and sales potential, and potential operational efficiencies gained. Changes to the significant inputs used in determining the fair value of the contingent consideration due to seller could result in a change in the fair value of the contingent consideration. However, the correlation and inverse relationship between higher projected financial results to the discount rate applied and probability of meeting the financial targets mitigates the effect of any changes to the unobservable inputs. The following tables set forth the Company's financial liabilities measured at fair value on a recurring basis and the basis of measurement at June 30, 2019 and December 31, 2018 (in thousands): Fair Value Measurements as of June 30, 2019 Total Level 1 Level 2 Level 3 Liabilities: Contingent consideration due to seller $ (2,100 ) — — $ (2,100 ) Fair Value Measurements as of December 31, 2018 Total Level 1 Level 2 Level 3 Liabilities: Contingent consideration due to seller $ (2,960 ) — — $ (2,960 ) The following table provides a reconciliation of the beginning and ending balances for the liabilities measured at fair value using significant unobservable inputs (Level 3) (in thousands): Due to Seller Liability Balance at December 31, 2018 $ (2,960 ) Change in fair value of contingent consideration due to seller (490 ) Payment of contingent consideration due to seller 1,350 Balance at June 30, 2019 $ (2,100 ) For the three months ended June 30, 2019 and 2018 , the Company recognized expense of $200 thousand and $50 thousand , respectively. For the six months ended June 30, 2019 and 2018 , the Company recognized expense of $490 thousand and $100 thousand , respectively. These changes in fair value resulted from using revised forecasts that took into account the most recent performance at each acquired business and the effect of the time value of money. During the six months ended June 30, 2019 and 2018 , the Company made contingent earn-out payments of $1.4 million and $0.9 million , respectively, to the sellers of businesses acquired by the Company.

Intangibles and Goodwill

Intangibles and Goodwill	6 Months Ended
	Jun. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Intangibles and Goodwill	Intangibles and Goodwill The balance of goodwill was $309.6 million as of June 30, 2019 and December 31, 2018 , as no changes occurred during the period. The following is a summary of amortizable intangible assets as of June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 December 31, 2018 Cost Accumulated Amortization Net Cost Accumulated Amortization Net Customer relationships $ 150,239 $ (62,626 ) $ 87,613 $ 150,239 $ (57,875 ) $ 92,364 Carrier relationships 18,300 (4,396 ) 13,904 18,300 (3,857 ) 14,443 Non-compete agreements 5,239 (3,391 ) 1,848 5,239 (3,003 ) 2,236 Trade names 5,640 (5,640 ) — 5,640 (5,119 ) 521 $ 179,418 $ (76,053 ) $ 103,365 $ 179,418 $ (69,855 ) $ 109,563 Note: Amounts may not foot due to rounding. The customer relationships are being amortized using an accelerated method over their estimated weighted-average useful life of 14.8 years , as an accelerated method best approximates the distribution of cash flows generated by the acquired customer relationships. The carrier relationships, non-compete agreements and trade names are being amortized using the straight-line method over their estimated weighted-average useful lives of 17.0 years , 6.7 years and 4.0 years , respectively. Amortization expense related to intangible assets was $3.0 million and $3.2 million for the three months ended June 30, 2019 and 2018 , respectively. Amortization expense was $6.2 million and $6.5 million for the six months ended June 30, 2019 and 2018 , respectively. The estimated amortization expense for the next five years and thereafter is as follows (in thousands): Remainder of 2019 $ 5,603 2020 10,973 2021 10,362 2022 10,005 2023 9,501 Thereafter 56,920 Total $ 103,365 Note: Amounts may not foot due to rounding.

Accrued Expenses and Other Nonc

Accrued Expenses and Other Noncurrent Liabilities	6 Months Ended
	Jun. 30, 2019
Payables and Accruals [Abstract]
Accrued Expenses and Other Noncurrent Liabilities	Accrued Expenses and Other Noncurrent Liabilities The components of accrued expenses at June 30, 2019 and December 31, 2018 were as follows (in thousands): June 30, 2019 December 31, 2018 Accrued compensation $ 22,874 $ 31,825 Accrued rebates 3,322 2,669 Accrued employee benefits 2,454 2,620 Accrued professional service fees 1,599 2,082 Accrued interest 879 1,017 Deferred rent — 2,439 Other 4,333 5,476 Total accrued expenses $ 35,461 $ 48,129 Note: Amounts may not foot due to rounding. The other noncurrent liabilities of $0.5 million at June 30, 2019 consist of the long-term portion of the Company's uncertain tax liability. The other noncurrent liabilities of $18.4 million at December 31, 2018 consist primarily of the portion of deferred rent in excess of twelve months and the long-term uncertain tax liability.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The following table shows the Company's effective income tax rate for the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended June 30, Six Months Ended 2019 2018 2019 2018 Income before provision for income taxes $ 7,117 $ 9,358 $ 12,807 $ 16,107 Income tax expense $ (2,050 ) $ (1,680 ) $ (4,244 ) $ (3,702 ) Effective tax rate 28.8 % 17.9 % 33.1 % 23.0 % The difference in the Company's effective tax rate for each of the three and six months ended June 30, 2019 and 2018 from the Company's statutory federal tax rate of 21%

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Basic earnings per common share is calculated by dividing net income by the weighted average number of common shares outstanding. Diluted earnings per common share is calculated by dividing net income by the weighted average shares outstanding plus share equivalents that would arise from the exercise of share options, and the vesting of restricted stock and performance shares. The computation of basic and diluted earnings per common share for the three and six months ended June 30, 2019 and 2018 is as follows (in thousands, except share and per share data): Three Months Ended June 30, Six Months Ended 2019 2018 2019 2018 Numerator: Net income $ 5,067 $ 7,678 $ 8,564 $ 12,405 Denominator: Denominator for basic earnings per common share - weighted-average shares 26,731,644 27,603,096 26,969,277 27,466,689 Effect of dilutive securities: Employee stock awards 59,951 268,850 154,594 332,249 Denominator for dilutive earnings per common share 26,791,595 27,871,946 27,123,871 27,798,938 Basic earnings per common share $ 0.19 $ 0.28 $ 0.32 $ 0.45 Diluted earnings per common share $ 0.19 $ 0.28 $ 0.32 $ 0.45 For the three and six months ended June 30, 2019 and 2018 , the Company excluded 63,978 and 2,538 unvested performance and market-based shares, respectively, from the calculation of diluted earnings per common share because the effect was anti-dilutive. There were no employee stock options and no unvested restricted stock excluded from the calculation of diluted earnings per common share. As of June 30, 2019 , none of the conditions allowing holders of the Notes (as defined in Note 12) to convert have been met and no conversion spread exists. As such, the Notes did not have a dilutive impact on diluted earnings per common share for the three and six months ended June 30, 2019 and 2018 .

Stock-Based Compensation Plans

Stock-Based Compensation Plans	6 Months Ended
	Jun. 30, 2019
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation Plans	Stock-Based Compensation Plans The Company recorded $2.4 million and $5.2 million in total stock-based compensation expense with corresponding income tax benefits of $0.6 million and $1.3 million for the three and six months ended June 30, 2019 , respectively. For the three and six months ended June 30, 2018 , the Company recorded $2.2 million and $4.7 million in total stock-based compensation expense with corresponding income tax benefits of $0.5 million and $1.2 million , respectively. During each of the six months ended June 30, 2019 and 2018 , the Company did no t grant any stock options. The Company granted 366,417 and 244,448 shares of restricted stock to various employees during the six months ended June 30, 2019 and 2018 , respectively. The Company provides a performance and market-based stock incentive plan for certain executives with vesting requirements based on specific financial and market-based performance measurements. The Company granted 105,543 and 97,966 shares of performance and market-based stock during the six months ended June 30, 2019 and 2018 , respectively.

Contingencies

Contingencies	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies In the normal course of business, the Company is subject to potential claims and disputes related to its business, including claims for freight lost or damaged in transit. Some of these matters may be covered by the Company's insurance and risk management programs or may result in claims or adjustments with the Company's carriers. No such matters are currently expected to have a material adverse effect on the Company's financial position, results of operations or cash flows. In July 2016, the Company received an unfavorable appeals assessment regarding a state activity-based tax matter of $1.3 million , including penalties and interest, for the state tax audit period from January 1, 2010 to June 30, 2014. The Company believes the assessment is without merit and is currently defending the Company's position through a formal appeals process. The Company has not recorded any potential loss related to this matter as of June 30, 2019 .

Long-Term Debt

Long-Term Debt	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt ABL Facility On October 23, 2018, the Company entered into Amendment No. 2 to its Revolving Credit and Security Agreement (the "Second Amendment"), which amends the terms of its existing Revolving Credit and Security Agreement, dated as of June 1, 2015, by and among the Company, the lenders party thereto, and PNC Bank, National Association, as administrative agent (as amended by the Second Amendment, the "Amended Credit Agreement"). The Amended Credit Agreement provides for a senior secured revolving credit facility in an initial aggregate principal amount of up to $350 million (the "Amended ABL Facility"), with an extended maturity date of October 23, 2023. The initial aggregate principal amount under the Amended ABL Facility may be increased from time to time by an additional $150 million to a maximum aggregate principal amount of $500 million ; provided that certain requirements are satisfied. The Company's obligations under the Amended ABL Facility are secured, on a first lien priority basis, by certain working capital assets. Interest is payable at a rate per annum equal to, at the option of the Company, any of the following, plus, in each case, an applicable margin: (a) a base rate determined by reference to the highest of (1) the federal funds effective rate, plus 0.50% , (2) the base commercial lending rate of PNC Bank, National Association and (3) a daily LIBOR rate, plus 1.00% ; or (b) a LIBOR rate determined by reference to the costs of funds for deposits in the relevant currency for the interest period relevant to such borrowing adjusted for certain additional costs. The applicable margin is 0.25% to 0.50% for borrowings at the base rate and 1.25% to 1.50% for borrowings at the LIBOR rate, in each case, based on the excess availability under the Amended ABL Facility. The terms of the Amended ABL Facility include various covenants, including a covenant that requires the Company to maintain a consolidated fixed charge coverage ratio at any time (a) a specified default occurs or (b) excess availability falls below certain specified levels. The Company incurred issuance costs of $0.8 million in 2018 related to the Amended ABL Facility. In 2015, the Company incurred issuance costs of $3.1 million related to the ABL Facility. If the Company has an amount outstanding on the ABL Facility, these issuance costs are presented on the consolidated balance sheet as a reduction to the carrying amount of the debt and amortized to interest expense using straight-line amortization over the 5 -year life of the Amended ABL Facility. If the Company has no outstanding draw on the ABL Facility, the unamortized issuance costs are presented as a deferred asset on the consolidated balance sheet. For the three months ended June 30, 2019 and 2018 , the Company recorded $0.1 million and $0.2 million of interest expense, respectively, related to ABL Facility issuance costs. For the six months ended June 30, 2019 and 2018 , the Company recorded $0.2 million and $0.4 million of interest expense, respectively, related to ABL Facility issuance costs. Under the Amended ABL Facility, the Company is required to pay a commitment fee in respect to the unutilized commitments under the Amended ABL Facility, calculated at a rate of 0.25% . The Company recognized interest expense related to the commitment fee and borrowings on the ABL Facility of $0.3 million and $0.2 million for the three months ended June 30, 2019 and 2018 , respectively. The Company recognized interest expense related to the commitment fee and borrowings on the ABL Facility of $0.5 million and $0.4 million for the six months ended June 30, 2019 and 2018 , respectively. The Company drew $15.0 million and $12.0 million on the ABL Facility during the six months ended June 30, 2019 and 2018, respectively, all of which was repaid as of June 30, 2019 and 2018 . No amounts were outstanding on the ABL Facility as of June 30, 2019 and 2018 . As there is no outstanding draw on the ABL Facility at June 30, 2019 , the unamortized issuance costs are presented as a deferred asset on the consolidated balance sheets. Since June 1, 2015, the Company has been in compliance with all covenants related to the ABL Facility. The issuance of letters of credit under the ABL Facility reduces available borrowings. As of June 30, 2019 , there were $0.7 million of letters of credit outstanding. The total draw allowed on the ABL Facility at June 30, 2019 , as determined by the working capital assets pledged as collateral, was $237.7 million . After adjusting for the letters of credit, the Company's remaining availability under the ABL Facility at June 30, 2019 was $237.0 million . Convertible Senior Notes On May 5, 2015, the Company issued $230 million aggregate principal amount of 2.50% convertible senior notes due 2020 (the “Notes”). The Notes bear interest at a rate of 2.50% per year payable semiannually in arrears in cash on May 1 and November 1 of each year, beginning on November 1, 2015. The Notes will mature on May 1, 2020, unless earlier converted or repurchased in accordance with the terms discussed below. The Notes are the Company's senior unsecured obligations and rank senior in right of payment to any of the Company's indebtedness that is expressly subordinated in right of payment to the Notes; equal in right of payment to any of the Company's unsecured indebtedness that is not so subordinated; effectively junior in right of payment to any of the Company's secured indebtedness to the extent of the value of the assets securing such indebtedness; and structurally junior to all indebtedness and other liabilities (including trade payables) of the Company's subsidiaries. The Notes will be convertible, under certain circumstances and during certain periods, into cash, shares of the Company's common stock, or a combination of cash and shares of common stock at the Company's election, at an initial conversion rate of 25.5428 shares of common stock per $1,000 principal amount of Notes, which is equivalent to an initial conversion price of approximately $39.15 per share of common stock. At issuance, the Company estimated the straight debt borrowing rates to be 5.75% for similar debt to the Notes without the conversion feature, which resulted in a fair value of the liability component of $198.5 million and a fair value of the equity component of $31.5 million . The fair value of the equity component was recorded as a debt discount, with the offset recorded as a credit to additional paid-in capital within stockholders' equity. The $31.5 million debt discount and Note issuance costs discussed below are being amortized to interest expense under the effective interest method over the 5 -year life of the Notes, using an effective interest rate of 6.33% . The Company allocated the total issuance costs related to the Notes to liability and equity components based on their relative fair values. Issuance costs attributable to the liability component were recorded on the consolidated balance sheets as a contra-liability that reduces the carrying amount of the convertible note liability. This amount is being amortized to interest expense over the term of the Notes using the effective interest method and an effective interest rate of 6.33% . Issuance costs attributable to the equity component were recorded as a charge to additional paid-in capital within stockholders' equity. The Company has the intent and ability to refinance on a long-term basis the remaining principal amount of the Notes on May 1, 2020 using the Amended ABL Facility, which is considered noncurrent. As of June 30, 2019, the Company continues to classify the convertible debt as a noncurrent liability on the consolidated balance sheet. The Company expects to settle any excess conversion premium that exists in shares of common stock. As such, the principal amount of the Notes will not be included in the calculation of diluted earnings per common share, but any conversion premium that exists will be included in the calculation of diluted earnings per common share using the treasury stock method. As of June 30, 2019 and 2018 , none of the conditions allowing holders of the Notes to convert have been met and no conversion spread exists. As such, the Notes did not have a dilutive impact on diluted earnings per common share for each of the three and six months ended June 30, 2019 and 2018 . During the six months ended June 30, 2019 , the Company repurchased $34.3 million par value of the Notes for $33.9 million . The Company accounted for these transactions in accordance with ASC 470-20, Debt with Conversion and Other Options , resulting in the recognition of a loss of $0.5 million and $0.7 million for the three and six months ended June 30, 2019 , respectively. The loss is primarily for the write-off of the unamortized debt discount related to the Notes, which was included in interest expense in the Company's respective consolidated statements of operations. During the six months ended June 30, 2018 , the Company did no t repurchase any of the Notes, and thus did no t have a corresponding gain or loss to record on the consolidated statements of operations for three and six ended June 30, 2018 . As of June 30, 2019 and December 31, 2018 , the carrying amounts of the Notes on the consolidated balance sheets were calculated as follows (in thousands): June 30, 2019 December 31, 2018 Convertible senior notes, principal amount $ 158,295 $ 192,585 Unamortized debt discount (4,102 ) (7,862 ) Unamortized debt issuance costs (811 ) (1,555 ) Convertible senior notes, net $ 153,381 $ 183,168 Note: Amounts may not foot due to rounding. The Notes are carried on the consolidated balance sheets at their principal amount, net of the unamortized debt discount and unamortized debt issuance costs, and are not marked to market each period. The approximate fair value of the Notes as of June 30, 2019 was $157.2 million . The fair value of the Notes was estimated based on the trading price of the Notes at June 30, 2019 . As trading volume is low, these are quoted prices for identical instruments in markets that are not active, and thus are Level 2 in the fair value hierarchy. For the three and six months ended June 30, 2019 and 2018 , interest expense related to the Notes consisted of the following (in thousands): Three Months Ended June 30, Six Months Ended 2019 2018 2019 2018 Contractual coupon interest $ 1,064 $ 1,438 $ 2,265 $ 2,875 Debt discount amortization 1,321 1,622 2,726 3,219 Loss on extinguishment of debt 513 — 711 — Debt issuance cost amortization 261 321 539 637 Interest expense, Notes $ 3,159 $ 3,380 $ 6,241 $ 6,730 Note: Amounts may not foot due to rounding. The undiscounted interest and principal payments due in relation to the Notes from June 30, 2019 to the maturity of the Notes on May 1, 2020 are as follows (in thousands): Total 2019 2020 Senior convertible notes, including interest $ 162,252 1,979 $ 160,274 Note: Amounts may not foot due to rounding.

Leases

Leases	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Leases	Leases The Company leases office space for purposes of conducting its business. Leases with an initial term of 12 months or less are not recorded on the balance sheet; lease expense for these leases is recognized on a straight-line basis over the lease term. All Company leases, consisting primarily of facility leases, were evaluated upon the adoption of ASC Topic 842, and it was determined that these were all operating leases. Most leases include one or more options to renew, with renewal terms that can extend the lease term. The Company also has some leases that include termination options. The exercise of lease renewal or termination options is at the Company's sole discretion, and it does not recognize these options as part of its right-of-use assets ("ROU assets") or lease liabilities. The Company's lease agreements do not contain any material residual value guarantees or material restrictive covenants. The Company determines if an arrangement contains a lease at inception. The Company has performed an evaluation of other contracts with customers and suppliers in accordance with ASC Topic 842 and has determined that, except for the facility leases described above, none of its contracts contain a lease. The balance sheet classification of lease assets and liabilities is as follows (in thousands): June 30, 2019 ROU assets: Operating lease assets $ 19,852 Operating lease liabilities: Current portion in other current liabilities $ 5,704 Noncurrent operating lease liabilities 33,174 Total operating lease liabilities $ 38,879 Note: Amounts may not foot due to rounding. The components of lease cost for the three and six months ended June 30, 2019 were as follows (in thousands): Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Operating lease cost $ 1,411 $ 2,863 Short-term lease cost 44 89 Total lease cost $ 1,455 $ 2,952 Cash paid for amounts included in the measurement of lease liabilities for the six months ended June 30, 2019 was $4.2 million and was included in net cash provided by operating activities in the consolidated statements of cash flows. The average lease term and discount rate were as follows: June 30, 2019 Weighted average remaining lease term (in years) 7.2 Weighted average operating discount rate 7.6 % The Company's leases generally do not provide an implicit rate, and therefore the Company uses its incremental borrowing rate as the discount rate when measuring operating lease liabilities. The incremental borrowing rate represents an estimate of the interest rate the Company would incur at lease commencement to borrow an amount equal to the lease payments on a collateralized basis over the term of a lease within a particular currency environment. The Company used incremental borrowing rates as of January 1, 2019 for operating leases that commenced prior to that date. As of June 30, 2019 , maturities of operating lease liabilities were as follows (in thousands): Operating Leases Remainder of 2019 $ 4,210 2020 8,119 2021 5,887 2022 6,178 2023 5,938 Thereafter 20,855 Total lease payments $ 51,187 Less: imputed interest 12,309 Total operating lease liabilities $ 38,879 Note: Amounts may not foot due to rounding. Practical Expedients The Company adopted the the package of practical expedients that allows it to (i) not reassess whether an arrangement contains a lease, (ii) carry forward its lease classification as operating or capital leases and (iii) not reassess its previously recorded initial direct costs. In addition, the Company elected the practical expedient to not separate lease and non-lease components whereby both components are accounted for and recognized as lease components.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Preparation of Financial Statements and Use of Estimates	Preparation of Financial Statements and Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenue and expenses during the reporting periods. Actual results can differ from those estimates.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying values of the Company's financial instruments, which consist of cash and cash equivalents, accounts receivable and accounts payable, approximate their fair values due to their short-term nature. The fair value of the acquired intangible assets was determined using a discounted cash flow analysis as further described in Note 3. The fair value of the due to seller liabilities are determined based on the likelihood of the Company making contingent earn-out payments (see Note 5). The fair value of the liability component of the Notes (as defined in Note 12) was determined using the discounted cash flow analysis discussed in Note 12.
New Accounting Pronouncements	Recent Accounting Pronouncements Recently adopted accounting pronouncements In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2016-02, Leases, requiring a lessee to record, on the balance sheet, the assets and liabilities for the right-of-use assets and lease obligations created by leases with lease terms of more than 12 months. In July 2018, the FASB issued ASU 2018-11, which added amendments to create an optional transition method that provided an option to use the effective date of Accounting Standards Codification ("ASC") 842, Leases ("ASC Topic 842"), as the date of initial application of the transition. In addition, the new standard requires enhanced qualitative and quantitative disclosures related to the amount, timing and uncertainty of cash flows arising from leases. The Company adopted this standard on January 1, 2019 using the modified retrospective approach. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. Upon adoption, the Company elected the package of practical expedients that allows it to (i) not reassess whether an arrangement contains a lease, (ii) carry forward its lease classification as operating or capital leases and (iii) not reassess its previously recorded initial direct costs. In addition, the Company elected the practical expedient to not separate lease and non-lease components whereby both components are accounted for and recognized as lease components. The adoption resulted in a lease asset of $21.0 million and lease liability of $41.2 million , respectively, as of January 1, 2019. The Company's previous liability for deferred rent of $20.3 million was offset against the right of use asset upon adoption of the new standard. The standard did not impact the Company's consolidated statement of operations and had no impact on cash flows. The Company fully describes the adoption and impact of this standard in Note 13. As part of the adoption of this standard, the Company implemented changes to its accounting policies, practices and internal controls over financial reporting. In June 2018, the FASB issued ASU 2018-07, Compensation - Stock Compensation , which expands the scope of Topic 718 to include all share-based payment transactions for acquiring goods and services from nonemployees. The amendments in this update are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, with early adoption permitted. The Company's current share-based payment awards to non-employees consist only of grants made to its non-employee Directors as compensation solely relates to each individual's role as a non-employee Director. As such, in accordance with ASC 718, the Company accounts for these share-based payment awards to its non-employee Directors in the same manner as share-based payment awards for its employees. The Company adopted this standard on January 1, 2019, and the amendments in this guidance had no effect on the accounting for its share-based payment awards to its non-employee Directors, and had no effect on the consolidated financial statements. Recently issued accounting pronouncements not yet adopted In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement , which modifies the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement. This new accounting standard will be effective for annual periods beginning after December 15, 2019. Early adoption is permitted. The Company is evaluating the effects that the adoption of this guidance will have on its disclosures. In January 2017, the FASB issued ASU 2017-04, Intangibles - Goodwill and Other: Simplifying the Test for Goodwill Impairment , to simplify the subsequent measurement of goodwill by eliminating Step 2 from the goodwill impairment test. This new accounting standard will be effective for annual periods beginning after December 15, 2019. Early adoption is permitted. The Company is evaluating the effects that the adoption of this guidance will have on its consolidated financial statements. In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326) , which replaces the incurred loss methodology previously employed to measure credit losses for most financial assets and requires the use of a forward-looking expected loss model. Current accounting delays the recognition of credit losses until it is probable a loss has been incurred, while the update will require financial assets to be measured at amortized costs less a reserve and equal to the net amount expected to be collected. This standard will be effective for annual periods beginning after December 15, 2019, including interim periods within those fiscal years, with early adoption permitted. The Company is evaluating the effects that the adoption of this guidance will have on its consolidated financial statements.

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of revenue	The following table presents the Company's revenue disaggregated by client type (in thousands): Three Months Ended June 30, Six Months Ended Client Type 2019 2018 2019 2018 Transactional $ 428,224 $ 502,788 $ 840,369 $ 955,897 Managed Transportation 125,551 132,023 251,490 256,005 Revenue $ 553,775 $ 634,811 $ 1,091,858 $ 1,211,902 Note: Amounts may not foot due to rounding. The following table presents the Company's revenue disaggregated by mode (in thousands): Three Months Ended June 30, Six Months Ended Mode 2019 2018 2019 2018 Truckload $ 362,254 $ 443,711 $ 716,572 $ 844,186 Less than truckload 165,046 160,584 319,985 307,818 Other revenue 26,476 30,516 55,301 59,898 Revenue $ 553,775 $ 634,811 $ 1,091,858 $ 1,211,902 Note: Amounts may not foot due to rounding.

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Financial assets and liabilities measured at fair value on a recurring basis	The following tables set forth the Company's financial liabilities measured at fair value on a recurring basis and the basis of measurement at June 30, 2019 and December 31, 2018 (in thousands): Fair Value Measurements as of June 30, 2019 Total Level 1 Level 2 Level 3 Liabilities: Contingent consideration due to seller $ (2,100 ) — — $ (2,100 ) Fair Value Measurements as of December 31, 2018 Total Level 1 Level 2 Level 3 Liabilities: Contingent consideration due to seller $ (2,960 ) — — $ (2,960 )
Reconciliation of the beginning and ending balances for the liabilities measured at fair value using significant unobservable inputs	The following table provides a reconciliation of the beginning and ending balances for the liabilities measured at fair value using significant unobservable inputs (Level 3) (in thousands): Due to Seller Liability Balance at December 31, 2018 $ (2,960 ) Change in fair value of contingent consideration due to seller (490 ) Payment of contingent consideration due to seller 1,350 Balance at June 30, 2019 $ (2,100 )

Intangibles and Goodwill (Table

Intangibles and Goodwill (Tables)	6 Months Ended
	Jun. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of amortizable intangible assets	The following is a summary of amortizable intangible assets as of June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 December 31, 2018 Cost Accumulated Amortization Net Cost Accumulated Amortization Net Customer relationships $ 150,239 $ (62,626 ) $ 87,613 $ 150,239 $ (57,875 ) $ 92,364 Carrier relationships 18,300 (4,396 ) 13,904 18,300 (3,857 ) 14,443 Non-compete agreements 5,239 (3,391 ) 1,848 5,239 (3,003 ) 2,236 Trade names 5,640 (5,640 ) — 5,640 (5,119 ) 521 $ 179,418 $ (76,053 ) $ 103,365 $ 179,418 $ (69,855 ) $ 109,563 Note: Amounts may not foot due to rounding.
Estimated amortization expense for the next five years and thereafter	The estimated amortization expense for the next five years and thereafter is as follows (in thousands): Remainder of 2019 $ 5,603 2020 10,973 2021 10,362 2022 10,005 2023 9,501 Thereafter 56,920 Total $ 103,365 Note: Amounts may not foot due to rounding.

Accrued Expenses and Other No_2

Accrued Expenses and Other Noncurrent Liabilities (Tables)	6 Months Ended
	Jun. 30, 2019
Payables and Accruals [Abstract]
Components of accrued expenses	The components of accrued expenses at June 30, 2019 and December 31, 2018 were as follows (in thousands): June 30, 2019 December 31, 2018 Accrued compensation $ 22,874 $ 31,825 Accrued rebates 3,322 2,669 Accrued employee benefits 2,454 2,620 Accrued professional service fees 1,599 2,082 Accrued interest 879 1,017 Deferred rent — 2,439 Other 4,333 5,476 Total accrued expenses $ 35,461 $ 48,129 Note: Amounts may not foot due to rounding.

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Reconciliation of effective income tax rate	The following table shows the Company's effective income tax rate for the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended June 30, Six Months Ended 2019 2018 2019 2018 Income before provision for income taxes $ 7,117 $ 9,358 $ 12,807 $ 16,107 Income tax expense $ (2,050 ) $ (1,680 ) $ (4,244 ) $ (3,702 ) Effective tax rate 28.8 % 17.9 % 33.1 % 23.0 %

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Computation of basic and diluted earnings per common share	The computation of basic and diluted earnings per common share for the three and six months ended June 30, 2019 and 2018 is as follows (in thousands, except share and per share data): Three Months Ended June 30, Six Months Ended 2019 2018 2019 2018 Numerator: Net income $ 5,067 $ 7,678 $ 8,564 $ 12,405 Denominator: Denominator for basic earnings per common share - weighted-average shares 26,731,644 27,603,096 26,969,277 27,466,689 Effect of dilutive securities: Employee stock awards 59,951 268,850 154,594 332,249 Denominator for dilutive earnings per common share 26,791,595 27,871,946 27,123,871 27,798,938 Basic earnings per common share $ 0.19 $ 0.28 $ 0.32 $ 0.45 Diluted earnings per common share $ 0.19 $ 0.28 $ 0.32 $ 0.45

Long-Term Debt (Tables)

Long-Term Debt (Tables)	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Schedule of convertible senior notes	As of June 30, 2019 and December 31, 2018 , the carrying amounts of the Notes on the consolidated balance sheets were calculated as follows (in thousands): June 30, 2019 December 31, 2018 Convertible senior notes, principal amount $ 158,295 $ 192,585 Unamortized debt discount (4,102 ) (7,862 ) Unamortized debt issuance costs (811 ) (1,555 ) Convertible senior notes, net $ 153,381 $ 183,168
Schedule of interest expense related to convertible senior notes	For the three and six months ended June 30, 2019 and 2018 , interest expense related to the Notes consisted of the following (in thousands): Three Months Ended June 30, Six Months Ended 2019 2018 2019 2018 Contractual coupon interest $ 1,064 $ 1,438 $ 2,265 $ 2,875 Debt discount amortization 1,321 1,622 2,726 3,219 Loss on extinguishment of debt 513 — 711 — Debt issuance cost amortization 261 321 539 637 Interest expense, Notes $ 3,159 $ 3,380 $ 6,241 $ 6,730 Note: Amounts may not foot due to rounding.
Schedule of maturities of convertible senior notes	The undiscounted interest and principal payments due in relation to the Notes from June 30, 2019 to the maturity of the Notes on May 1, 2020 are as follows (in thousands): Total 2019 2020 Senior convertible notes, including interest $ 162,252 1,979 $ 160,274

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Schedule of Leases	The balance sheet classification of lease assets and liabilities is as follows (in thousands): June 30, 2019 ROU assets: Operating lease assets $ 19,852 Operating lease liabilities: Current portion in other current liabilities $ 5,704 Noncurrent operating lease liabilities 33,174 Total operating lease liabilities $ 38,879
Components of lease cost	The average lease term and discount rate were as follows: June 30, 2019 Weighted average remaining lease term (in years) 7.2 Weighted average operating discount rate 7.6 % The components of lease cost for the three and six months ended June 30, 2019 were as follows (in thousands): Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Operating lease cost $ 1,411 $ 2,863 Short-term lease cost 44 89 Total lease cost $ 1,455 $ 2,952
Maturities of operating lease liabilities	As of June 30, 2019 , maturities of operating lease liabilities were as follows (in thousands): Operating Leases Remainder of 2019 $ 4,210 2020 8,119 2021 5,887 2022 6,178 2023 5,938 Thereafter 20,855 Total lease payments $ 51,187 Less: imputed interest 12,309 Total operating lease liabilities $ 38,879

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease assets	$ 19,852		$ 0
Noncurrent operating lease liabilities	$ 33,174		0
Deferred rent			$ 20,300
ASU 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease assets		$ 21,000
Noncurrent operating lease liabilities		$ 41,200

Acquisitions (Details)

Acquisitions (Details) - USD ($) $ / shares in Units, $ in Thousands	Jul. 06, 2018	Jun. 30, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Common stock, par value (USD per share)		$ 0.0001	$ 0.0001
Goodwill		$ 309,589	$ 309,589
Goodwill deductible for U.S. income tax purposes	$ 900
Freight Management Plus, Inc.
Business Acquisition [Line Items]
Amount paid at closing	6,700
Purchase price paid with common stock	$ 700
Common stock, par value (USD per share)	$ 0.0001
Potential earn out payment	$ 2,900
Aggregate purchase price	10,500
Goodwill	2,300
Contingent consideration obligation	1,400	$ 2,100
Customer relationship intangible asset	$ 5,100

Revenue (Details)

Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jan. 01, 2018
Disaggregation of Revenue [Line Items]
Cumulative impact of adoption					$ 1,136
Revenue	$ 553,775	$ 634,811	$ 1,091,858	$ 1,211,902
Truckload
Disaggregation of Revenue [Line Items]
Revenue	362,254	443,711	716,572	844,186
Less than truckload
Disaggregation of Revenue [Line Items]
Revenue	165,046	160,584	319,985	307,818
Other revenue
Disaggregation of Revenue [Line Items]
Revenue	26,476	30,516	55,301	59,898
Transactional
Disaggregation of Revenue [Line Items]
Revenue	428,224	502,788	840,369	955,897
Managed Transportation
Disaggregation of Revenue [Line Items]
Revenue	$ 125,551	$ 132,023	$ 251,490	$ 256,005
Retained Earnings
Disaggregation of Revenue [Line Items]
Cumulative impact of adoption					1,136
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09 | Retained Earnings
Disaggregation of Revenue [Line Items]
Cumulative impact of adoption					$ 1,100

Fair Value Measurement - Narrat

Fair Value Measurement - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Probability of reaching the forecast maximum (as a percent)			100.00%
Payment of contingent consideration due to seller			$ 1,400	$ 900
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Change in fair value			(490)
Payment of contingent consideration due to seller			1,350
Selling, general and administrative expenses | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Change in fair value	$ (200)	$ (50)	$ (490)	$ (100)
Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Discount rate used to determine fair value of contingent consideration	5.00%		5.00%
Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Discount rate used to determine fair value of contingent consideration	7.00%		7.00%
Contingent consideration
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Contingent consideration due to seller	$ (2,100)		$ (2,100)		$ (3,000)

Fair Value Measurement - Assets

Fair Value Measurement - Assets and Liabilities at Fair Value (Details) - Contingent consideration - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Liabilities:
Contingent consideration due to seller	$ (2,100)	$ (3,000)
Fair Value, Measurements, Recurring
Liabilities:
Contingent consideration due to seller	(2,100)	(2,960)
Fair Value, Measurements, Recurring | Level 1
Liabilities:
Contingent consideration due to seller	0	0
Fair Value, Measurements, Recurring | Level 2
Liabilities:
Contingent consideration due to seller	0	0
Fair Value, Measurements, Recurring | Level 3
Liabilities:
Contingent consideration due to seller	$ (2,100)	$ (2,960)

Fair Value Measurement - Reconc

Fair Value Measurement - Reconciliation of Liabilities Using Level 3 (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Payment of contingent consideration due to seller	$ 1,400	$ 900
Level 3
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	(2,960)
Change in fair value of contingent consideration due to seller	(490)
Payment of contingent consideration due to seller	1,350
Balance at end of period	$ (2,100)

Intangibles and Goodwill - Inta

Intangibles and Goodwill - Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Intangible assets:
Goodwill	$ 309,589		$ 309,589		$ 309,589
Summary of amortizable intangible assets:
Cost	179,418		179,418		179,418
Accumulated Amortization	(76,053)		(76,053)		(69,855)
Net	103,365		103,365		109,563
Amortization expense	3,000	$ 3,200	6,200	$ 6,500
Estimated amortization expense for the next five years and thereafter:
Remainder of 2019	5,603		5,603
2020	10,973		10,973
2021	10,362		10,362
2022	10,005		10,005
2023	9,501		9,501
Thereafter	56,920		56,920
Net	103,365		103,365		109,563
Customer relationships
Summary of amortizable intangible assets:
Cost	150,239		150,239		150,239
Accumulated Amortization	(62,626)		(62,626)		(57,875)
Net	87,613		$ 87,613		92,364
Weighted-average, useful life			14 years 9 months 18 days
Estimated amortization expense for the next five years and thereafter:
Net	87,613		$ 87,613		92,364
Carrier relationships
Summary of amortizable intangible assets:
Cost	18,300		18,300		18,300
Accumulated Amortization	(4,396)		(4,396)		(3,857)
Net	13,904		$ 13,904		14,443
Weighted-average, useful life			17 years
Estimated amortization expense for the next five years and thereafter:
Net	13,904		$ 13,904		14,443
Non-compete agreements
Summary of amortizable intangible assets:
Cost	5,239		5,239		5,239
Accumulated Amortization	(3,391)		(3,391)		(3,003)
Net	1,848		$ 1,848		2,236
Weighted-average, useful life			6 years 8 months 12 days
Estimated amortization expense for the next five years and thereafter:
Net	1,848		$ 1,848		2,236
Trade names
Summary of amortizable intangible assets:
Cost	5,640		5,640		5,640
Accumulated Amortization	(5,640)		(5,640)		(5,119)
Net	0		$ 0		521
Weighted-average, useful life			4 years
Estimated amortization expense for the next five years and thereafter:
Net	$ 0		$ 0		$ 521

Accrued Expenses and Other No_3

Accrued Expenses and Other Noncurrent Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Accrued compensation	$ 22,874	$ 31,825
Accrued rebates	3,322	2,669
Accrued employee benefits	2,454	2,620
Accrued professional service fees	1,599	2,082
Accrued interest	879	1,017
Deferred rent	0	2,439
Other	4,333	5,476
Total accrued expenses	35,461	48,129
Other noncurrent liabilities	$ 533	$ 18,369

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Income before provision for income taxes	$ 7,117	$ 9,358	$ 12,807	$ 16,107
Income tax expense	$ (2,050)	$ (1,680)	$ (4,244)	$ (3,702)
Effective tax rate	28.80%	17.90%	33.10%	23.00%
Federal tax rate	21.00%	21.00%	21.00%	21.00%

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Numerator:
Net income	$ 5,067	$ 3,497	$ 7,678	$ 4,727	$ 8,564	$ 12,405
Denominator:
Denominator for basic earnings per common share - weighted-average shares (in shares)	26,731,644		27,603,096		26,969,277	27,466,689
Effect of dilutive securities:
Employee stock awards (in shares)	59,951		268,850		154,594	332,249
Denominator for dilutive earnings per common share (in shares)	26,791,595		27,871,946		27,123,871	27,798,938
Basic earnings per common share (in usd per share)	$ 0.19		$ 0.28		$ 0.32	$ 0.45
Diluted earnings per common share (in usd per share)	$ 0.19		$ 0.28		$ 0.32	$ 0.45
Performance shares
Anti-dilutive securities excluded from the calculation of earnings per share:
Shares excluded from the calculation of diluted earnings per share (in shares)	63,978		2,538		63,978	2,538
Employee stock option
Anti-dilutive securities excluded from the calculation of earnings per share:
Shares excluded from the calculation of diluted earnings per share (in shares)	0		0		0	0
Restricted stock
Anti-dilutive securities excluded from the calculation of earnings per share:
Shares excluded from the calculation of diluted earnings per share (in shares)	0		0		0	0

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Stock based compensation plans:
Stock-based compensation expense	$ 2.4	$ 2.2	$ 5.2	$ 4.7
Tax benefits from stock-based compensation expense	$ 0.6	$ 0.5	$ 1.3	$ 1.2
Grants in period, options (in shares)			0	0
Restricted stock
Stock based compensation plans:
Grants in period, other than options (in shares)			366,417	244,448
Performance and market-based stock
Stock based compensation plans:
Grants in period, other than options (in shares)			105,543	97,966

Contingencies (Details)

Contingencies (Details) $ in Millions	Jul. 31, 2016USD ($)
State Tax Audit
Loss Contingencies [Line Items]
Amount of assessment including penalties and interest	$ 1.3

Long-Term Debt - Line of Credit

Long-Term Debt - Line of Credit (Details) - ABL Facility - USD ($)	Oct. 23, 2018	Jun. 01, 2015	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Line of Credit Facility [Line Items]
Issuance costs	$ 800,000	$ 3,100,000
Life of ABL facility (in years)	5 years
Amortization of debt issuance costs			$ 100,000	$ 200,000	$ 200,000	$ 400,000
Commitment fee and borrowings interest expense			300,000	200,000	500,000	400,000
Remaining borrowing capacity			237,000,000		$ 237,000,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Current borrowing capacity	$ 350,000,000
Increase to borrowing capacity	150,000,000
Maximum borrowing capacity	$ 500,000,000
Commitment fee percentage					0.25%
Proceeds from borrowing on ABL facility					$ 15,000,000	12,000,000
ABL facility, outstanding borrowings			0	$ 0	0	$ 0
Remaining borrowing capacity			237,700,000		237,700,000
Revolving Credit Facility | Federal Funds Effective Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate (as a percent)	0.50%
Revolving Credit Facility | Federal Funds Effective Rate | Minimum
Line of Credit Facility [Line Items]
Basis spread on variable rate (as a percent)	0.25%
Revolving Credit Facility | Federal Funds Effective Rate | Maximum
Line of Credit Facility [Line Items]
Basis spread on variable rate (as a percent)	0.50%
Revolving Credit Facility | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate (as a percent)	1.00%
Revolving Credit Facility | LIBOR | Minimum
Line of Credit Facility [Line Items]
Basis spread on variable rate (as a percent)	1.25%
Revolving Credit Facility | LIBOR | Maximum
Line of Credit Facility [Line Items]
Basis spread on variable rate (as a percent)	1.50%
Letter of Credit
Line of Credit Facility [Line Items]
Letters of credit outstanding, amount			$ 700,000		$ 700,000

Long-Term Debt - Convertible Se

Long-Term Debt - Convertible Senior Notes (Details) - Senior convertible notes, including interest	May 05, 2015USD ($)$ / shares	Jun. 30, 2019USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2018USD ($)	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
Stated interest rate	2.50%
Conversion ratio	25.5428
Debt conversion, converted instrument, amount	$ 1,000
Conversion price (in usd per share) | $ / shares	$ 39.15
Repurchased face amount		$ 34,300,000	$ 0	$ 34,300,000	$ 0
Repayments of debt				33,900,000
Gain (loss) on extinguishment of debt		513,000	0	711,000	0
Carrying amount of Notes on the balance sheet:
Convertible senior notes, principal amount	$ 230,000,000	158,295,000		158,295,000		$ 192,585,000
Unamortized debt discount		(4,102,000)		(4,102,000)		(7,862,000)
Unamortized debt issuance costs		(811,000)		(811,000)		(1,555,000)
Convertible senior notes, net		153,381,000		153,381,000		$ 183,168,000
Convertible senior notes, fair value		157,200,000		157,200,000
Contractual coupon interest		1,064,000	1,438,000	2,265,000	2,875,000
Debt discount amortization		1,321,000	1,622,000	2,726,000	3,219,000
Amortization of debt issuance costs		261,000	321,000	539,000	637,000
Interest expense		$ 3,159,000	$ 3,380,000	$ 6,241,000	$ 6,730,000
Level 2
Debt Instrument [Line Items]
Straight debt borrowing rate	5.75%
Fair value of liability component	$ 198,500,000
Fair value of equity component	$ 31,500,000
Discount amortization period	5 years
Effective interest rate	6.33%

Long-Term Debt - Maturity Sched

Long-Term Debt - Maturity Schedule (Details) - Senior convertible notes, including interest $ in Thousands	Jun. 30, 2019USD ($)
Debt Instrument [Line Items]
Total	$ 162,252
2019	1,979
2020	$ 160,274

Leases (Details)

Leases (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Leases [Abstract]
Operating lease assets	$ 19,852	$ 0
Current portion in other current liabilities	5,704
Noncurrent operating lease liabilities	33,174	$ 0
Total operating lease liabilities	$ 38,879

Leases - Lease Costs (Details)

Leases - Lease Costs (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019USD ($)	Jun. 30, 2019USD ($)
Leases [Abstract]
Operating lease cost	$ 1,411	$ 2,863
Short-term lease cost	44	89
Total lease cost	$ 1,455	$ 2,952
Weighted average remaining lease term (in years)	7 years 2 months 12 days	7 years 2 months 12 days
Weighted average operating discount rate	7.60%	7.60%

Leases - Other Lease Informatio

Leases - Other Lease Information (Details) $ in Millions	6 Months Ended
	Jun. 30, 2019USD ($)
Leases [Abstract]
Operating lease payments	$ 4.2

Leases - Future Maturities (Det

Leases - Future Maturities (Details) $ in Thousands	Jun. 30, 2019USD ($)
Leases [Abstract]
Remainder of 2019	$ 4,210
2020	8,119
2021	5,887
2022	6,178
2023	5,938
Thereafter	20,855
Total lease payments	51,187
Less: imputed interest	12,309
Total operating lease liabilities	$ 38,879