Commercehub (CHUBB) 10-K 1 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Feb. 21, 2018	Jun. 30, 2017
Entity Information [Line Items]
Entity Registrant Name	COMMERCEHUB, INC.
Entity Central Index Key	1,665,658
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Amendment Flag	false
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 711.4
Common Series A
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding (in shares)		13,599,641
Common Series B
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding (in shares)		707,567
Common Series C
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding (in shares)		29,199,753

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 19,841	$ 6,471
Accounts receivable, net of allowances of $1,084 and $200, respectively	21,310	18,109
Prepaid income taxes	0	4,311
Prepaid expenses and other current assets	1,652	1,549
Total current assets	42,803	30,440
Capitalized software, net	2,850	6,716
Deferred services costs	4,853	4,989
Property and equipment, net	6,066	7,629
Goodwill	21,410	21,410
Deferred income taxes	5,798	7,714
Other long-term assets	1,339	1,122
Total assets	85,119	80,020
Current liabilities:
Accounts payable and accrued expenses	3,360	2,135
Accrued payroll and related expenses	9,429	7,435
Income taxes payable	962	7
Deferred revenue	5,339	5,149
Total current liabilities	19,090	14,726
Deferred revenue, long-term	8,272	7,581
Other long-term liabilities	3,210	1,135
Long-term debt	0	26,000
Total liabilities	30,572	49,442
Equity:
Preferred stock, $0.01 par value. Authorized shares of 50,000,000; 0 shares issued and outstanding at December 31, 2017 and 2016	0	0
Additional paid-in capital	31,010	16,904
Accumulated other comprehensive loss	(1)	0
Retained earnings	23,103	13,245
Total equity	54,547	30,578
Total liabilities and equity	85,119	80,020
Common Series A
Equity:
Common stock	136	135
Common Series B
Equity:
Common stock	7	7
Common Series C
Equity:
Common stock	$ 292	$ 287

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Allowance for accounts receivable	$ 1,084	$ 200
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	50,000,000	50,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common Series A
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	40,000,000	40,000,000
Common stock, shares issued (in shares)	13,599,641	13,536,502
Common stock, shares outstanding (in shares)	13,599,641	13,536,502
Common Series B
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,500,000	1,500,000
Common stock, shares issued (in shares)	707,567	711,992
Common stock, shares outstanding (in shares)	707,567	711,992
Common Series C
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	83,000,000	83,000,000
Common stock, shares issued (in shares)	29,171,981	28,672,805
Common stock, shares outstanding (in shares)	29,171,981	28,672,805

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Revenue (Note 8)	$ 111,121	$ 100,552	$ 87,614
Cost of revenue	21,600	23,057	22,700
Gross profit	89,521	77,495	64,914
Operating expenses:
Research and development	25,559	19,187	16,304
Sales and marketing	8,576	11,334	11,287
General and administrative	28,920	30,282	44,271
Total operating expenses	63,055	60,803	71,862
Income (loss) from operations	26,466	16,692	(6,948)
Other (expense) income:
Interest expense	(738)	(707)	0
Interest income	6	273	600
Total other (expense) income	(732)	(434)	600
Income (loss) before income taxes	25,734	16,258	(6,348)
Income tax expense (benefit)	15,876	7,162	(1,881)
Net income (loss)	9,858	9,096	(4,467)
Currency translation adjustment	(1)	0	0
Total comprehensive income (loss)	$ 9,857	$ 9,096	$ (4,467)
Earnings (loss) per share:
Basic (in dollars per share)	$ 0.23	$ 0.21	$ (0.10)
Diluted (in dollars per share)	$ 0.22	$ 0.21	$ (0.10)
Shares used in computing earnings (loss) per share:
Basic (in shares)	43,204	42,831	42,703
Diluted (in shares)	45,230	44,343	42,703

Consolidated Statement of Equit

Consolidated Statement of Equity - USD ($) $ in Thousands	Total	Common Stock	Common StockCommon Series A	Common StockCommon Series B	Common StockCommon Series C	APIC	Parent's Investment	AOCL	Retained Earnings
Beginning balance at Dec. 31, 2014	$ 32,115						$ 22,915		$ 9,200
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options	33						33
Repurchase of outstanding shares	(164)						(164)
Cash dividends paid	(584)								(584)
Net income (loss)	(4,467)								(4,467)
Ending balance at Dec. 31, 2015	26,933						22,784		4,149
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options	773	$ 1				$ 772
Net income (loss)	9,096								9,096
Exercise of stock options	73						73
Exercise of stock options (in shares)			15,268		96,917
Contribution from Parent	6,000						6,000
Cash dividends paid to Parent and others	(19,730)						(19,730)
Change in capitalization in connection with the Spin-Off (in shares)			13,522,288	711,992	28,468,562
Change in capitalization in connection with the Spin-Off	0	427				8,700	(9,127)
Reclassification of share-based compensation liability	12,489					12,489
Issuance of minority shares (in shares)					109,354
Issuance of minority shares	0	1				(1)
Forfeiture of net operating losses to Parent	(9,785)					(9,785)
Share-based compensation expense	4,730					4,730
Excess tax deduction from the exercise of stock options	(1)					(1)
Issuance of restricted stock units (in shares)			2		7
Cancellation of restricted shares (in shares)			(1,056)		(2,035)
Ending balance (in shares) at Dec. 31, 2016			13,536,502	711,992	28,672,805
Ending balance at Dec. 31, 2016	30,578	429				16,904	0	$ 0	13,245
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options	3,289	4				3,285
Net income (loss)	9,858								9,858
Exercise of stock options (in shares)			61,248		345,727
Share-based compensation expense	8,629					8,629
Issuance of restricted stock units (in shares)			151		123,977
Issuance of restricted stock units	0	1				(1)
Cancellation of restricted shares (in shares)			(2,685)		(6,826)
Adjustment to net operating loss forfeiture to Parent	1,655					1,655
Issuance of common stock under employee stock purchase plan (in shares)					36,298
Issuance of common stock under employee stock purchase plan	464	1				463
Issuance of deferred stock units	75					75
Conversion of Series B to Series A shares (in shares)			4,425	(4,425)
Other comprehensive loss	(1)							(1)
Ending balance (in shares) at Dec. 31, 2017			13,599,641	707,567	29,171,981
Ending balance at Dec. 31, 2017	$ 54,547	$ 435				$ 31,010	$ 0	$ (1)	$ 23,103

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income (loss)	$ 9,858,000	$ 9,096,000	$ (4,467,000)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	8,032,000	9,803,000	7,794,000
Amortization of debt issuance costs	221,000	111,000	0
Share-based compensation expense	8,629,000	11,290,000	42,150,000
Deferred income taxes	3,571,000	21,326,000	(12,289,000)
Bad debt expense	1,269,000	629,000	481,000
Accrued interest income	0	(273,000)	(600,000)
Impairment and loss on disposal of long-term assets	310,000	179,000	0
Change in operating assets and liabilities, net of acquisition:
Accounts receivable	(4,470,000)	(2,326,000)	(816,000)
Prepaid expenses and other assets	(532,000)	(599,000)	(40,000)
Income taxes, net	5,266,000	(4,304,000)	0
Deferred costs	136,000	(33,000)	(1,094,000)
Deferred revenue	883,000	708,000	2,031,000
Accounts payable and accrued expenses	2,210,000	166,000	(2,683,000)
Accrued payroll and related expenses	2,718,000	1,901,000	2,097,000
Share-based compensation liability payments	0	(86,684,000)	(7,507,000)
Parent receivables and payables, net	0	(9,112,000)	(523,000)
Net cash provided by (used in) operating activities	38,101,000	(48,122,000)	24,534,000
Cash flows from investing activities:
Purchases of property and equipment	(1,315,000)	(4,995,000)	(4,158,000)
Additions to capitalized software	(1,247,000)	(4,545,000)	(6,484,000)
Acquisition of business, net of cash acquired	0	0	(20,225,000)
Collection of note receivable - Parent	0	36,380,000	0
Net cash (used in) provided by investing activities	(2,562,000)	26,840,000	(30,867,000)
Cash flows from financing activities:
Borrowings on revolver	0	50,000,000	0
Payments on revolver	(26,000,000)	(24,000,000)	0
Cash paid for debt issuance costs	0	(1,100,000)	0
Purchase of treasury stock	0	(3,600,000)	(164,000)
Cash received from exercise of stock options	3,289,000	846,000	33,000
Cash received from employee stock purchase plan	464,000	0	0
Cash received from deferred stock units	75,000	0	0
Borrowings on note payable - Parent	0	28,664,000	0
Payments on note payable - Parent	0	(28,664,000)	0
Contribution from Parent	0	6,000,000	0
Dividends paid to Parent and other pre-Spin-Off shareholders	0	(19,730,000)	(584,000)
Net cash (used in) provided by financing activities	(22,172,000)	8,416,000	(715,000)
Currency effect on cash and cash equivalents	3,000	0	0
Net increase (decrease) in cash and cash equivalents	13,370,000	(12,866,000)	(7,048,000)
Cash and cash equivalents, beginning of period	6,471,000	19,337,000	26,385,000
Cash and cash equivalents, end of period	19,841,000	6,471,000	19,337,000
Supplemental disclosure of non-cash investing and financing activities:
Contractual obligations for acquisition of fixed assets	360,000	0	876,000
Supplemental disclosures of cash flow information:
Cash paid for interest	462,000	531,000	0
Cash paid for taxes	8,505,000	7,809,000	11,723,000
Collection of federal tax benefit from Parent	$ 0	$ 8,522,000	$ 0

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business CommerceHub, Inc. ("CommerceHub," the "Company," "us," "we" and "our") was founded in 1997 (then known as Commerce Technologies, Inc. ("CTI")) and is headquartered in Albany, New York, with additional locations in Seattle, Washington and Hertford, England. We are a leading provider of cloud-based ecommerce fulfillment and marketing solutions for large retailers, marketplaces, consumer brands and their suppliers. Our solutions help our customers implement strategies that increase their ecommerce revenues and create meaningful operational efficiencies within their supply chains. The customized solutions we create for specific customer types utilize our cloud-based software and service capabilities to more effectively fulfill consumer orders, generate consumer demand for products and deliver products to consumers. During November 2015, the board of directors of Liberty Interactive Corporation, our former parent company ("Liberty" or "Parent"), authorized a plan to distribute to the holders of Liberty's Series A and Series B Liberty Ventures common stock, shares of CommerceHub (the "Spin-Off"). At the time, CommerceHub was a newly formed Delaware corporation that, pursuant to an internal restructuring, effective July 21, 2016, became the parent of Commerce Technologies, LLC, a Delaware limited liability company that, as a result of the restructuring, is the successor to CTI, the entity through which CommerceHub transacted prior to the Spin-Off. The Spin-Off was completed on July 22, 2016 and was effected as a pro rata dividend of shares of CommerceHub to the stockholders of Liberty's Series A and Series B Liberty Ventures common stock. The Internal Revenue Service (“IRS”) has completed its review of the Spin-Off and has notified Liberty that it agreed with the nontaxable characterization of the Spin-Off. Following the Spin-Off, CommerceHub operates as a stand-alone publicly traded company, and neither Liberty nor CommerceHub has any stock ownership, beneficial or otherwise, in the other.

Basis of Presentation

Basis of Presentation	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements include the accounts of CommerceHub and its subsidiaries. All intercompany accounts and transactions have been eliminated in the consolidated financial statements, which have been prepared in conformity with U.S. generally accepted accounting principles ("GAAP"). Use of Estimates Preparing these consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates and assumptions. Segment and Geographic Information Operating segments are components of our business for which discrete financial information is available and evaluated by the chief operating decision maker ("CODM") for purposes of allocating resources and evaluating financial performance. Our Chief Executive Officer, who is our CODM, reviews the Company's consolidated financial information results to allocate resources and evaluate performance. As such, the Company operates as a single segment. The following table summarizes revenue by type (in thousands): Year Ended December 31, 2017 2016 2015 Revenue: Core Drop-Ship Revenue Order fee revenue $ 59,788 $ 52,095 $ 45,269 Subscription and other platform revenue 35,224 32,617 27,498 Set-up and professional services revenue 7,047 5,692 4,293 Total core drop-ship revenue 102,059 90,404 77,060 Demand channel revenue 9,062 10,148 10,554 Total revenue $ 111,121 $ 100,552 $ 87,614 We generate nearly all of our revenue in the United States and Canada. For the years ended December 31, 2017 , 2016 and 2015, we generated approximately 96% of our revenue from customers located in the United States. Substantially all of our assets are located within the United States. Updated Presentation of Revenue by Type During the year ended December 31, 2017, we updated the way in which we present revenue by type. The table below provides revenue by type for previously reported periods under our current presentation. For the three months ended: 9/30/2017 6/30/2017 3/31/2017 12/31/2016 9/30/2016 6/30/2016 3/31/2016 12/31/2015 9/30/2015 6/30/2015 3/31/2015 Revenue by type: Core drop-ship revenue: Order fee revenue $ 12,276 $ 12,901 $ 12,038 $ 19,569 $ 10,900 $ 11,227 $ 10,399 $ 17,070 $ 9,414 $ 9,683 $ 9,102 Subscription and other platform revenue 8,544 8,432 8,451 9,195 8,053 7,827 7,542 7,728 6,767 6,529 6,474 Set-up and professional services revenue 1,713 1,622 1,725 1,387 1,431 1,491 1,383 1,238 1,106 1,055 894 Total core drop-ship revenue 22,533 22,955 22,214 30,151 20,384 20,545 19,324 26,036 17,287 17,267 16,470 Demand channel revenue 2,081 2,253 2,354 2,730 2,094 2,558 2,766 3,235 2,408 2,591 2,320 Total $ 24,614 $ 25,208 $ 24,568 $ 32,881 $ 22,478 $ 23,103 $ 22,090 $ 29,271 $ 19,695 $ 19,858 $ 18,790

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Cash and Cash Equivalents The Company considers all highly liquid securities with original maturities of 90 days or less to be cash equivalents, including bank and money market accounts. Cash and cash equivalents at December 31, 2017 consisted principally of cash and money market accounts held at financial institutions in the United States that management believes to be reputable. Cash and cash equivalents at December 31, 2016 consisted principally of cash held at such financial institutions. At times, our accounts exceed insured limits. Money market accounts are carried at cost, which approximates fair value. Accounts Receivable and Allowance for Doubtful Accounts The Company grants credit to customers in the normal course of business without collateral. Accounts receivable are stated net of allowances for doubtful accounts, which represent estimated losses resulting from the inability of certain customers to make the required payments. When determining the allowances for doubtful accounts, we take several factors into consideration, including the overall composition of the accounts receivable aging, our prior history of accounts receivable write-offs, the types of customers and our experience with specific customers. We write off accounts receivable when they are determined to be uncollectible. Changes in the allowances for doubtful accounts are recorded as bad debt expense and are included in general and administrative expenses in our consolidated statements of comprehensive income (loss). Our allowance for doubtful accounts activity, included in accounts receivable, net, was as follows for the years ended December 31, (in thousands): 2017 2016 2015 Balances as of January 1 $ 200 $ 239 $ 233 Provision for doubtful accounts 1,269 629 481 Write-offs (385 ) (668 ) (475 ) Balances as of December 31 $ 1,084 $ 200 $ 239 The increase in our provision for doubtful accounts for the year ended December 31, 2017 is due, primarily, to customer bankruptcies. Property and Equipment Property and equipment are stated at cost. Equipment under capital leases are stated at the present value of minimum lease payments. Repairs and maintenance costs are expensed as incurred. Depreciation of property and equipment is computed using the straight-line method over the following estimated useful lives: Computer equipment 3 to 5 years Furniture and fixtures 5 years Leasehold improvements lesser of remaining lease term or estimated useful life Capitalized Software Costs The Company capitalizes the cost of payroll, payroll-related costs and third-party consulting fees incurred in the direct development or enhancement of solutions as internal-use software. During 2016 , we changed and further refined our methodologies and processes to estimate the portion of software development costs that is eligible to be capitalized, which is assessed at a project level. Development costs incurred during the preliminary project stage or costs incurred for requirements gathering, data conversion activities, training, maintenance and minor enhancements are expensed as incurred. Development costs incurred for the coding, configuration, interfacing, automation and testing of new functionality after the preliminary project stage is complete are capitalized. Capitalized software costs are amortized on a straight-line basis over two to three years, based on the nature and estimated useful life of the applicable solution. Amortization of capitalized software costs is included in cost of revenue within the consolidated statements of comprehensive income (loss). Deferred Services Costs The Company defers direct payroll, payroll-related costs and third-party consulting costs incurred for the set-up and integration of new customers on our platform and for enhancements we make to our platform that are particular to specific customers. Deferred services costs associated with the integration of customers on our platform are recognized over the estimated life of such customers. Deferred services costs incurred to enhance existing customers' platforms are recognized over the estimated remaining customer life. Amortization of deferred services costs is included in cost of revenue within the consolidated statements of comprehensive income (loss). Impairment of Long-Lived Assets Long-lived assets, such as property and equipment, capitalized software costs, deferred services costs and intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset or asset group to be tested for possible impairment, the Company first compares undiscounted cash flows expected to be generated by that asset or asset group to its carrying value. If the carrying value of the long-lived asset or asset group is not recoverable on an undiscounted cash flow basis, an impairment is recognized to the extent that the carrying value exceeds its fair value. Fair value may be determined through various valuation techniques, including discounted cash flow models, quoted market values and independent third-party appraisals, as considered necessary or appropriate. Goodwill Goodwill is an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Goodwill is reviewed for impairment at least annually as of October 1, and more frequently if events or changes in circumstances indicate that goodwill might be impaired. GAAP provides the option to perform a qualitative assessment to determine whether it is more-likely-than-not that the fair value of a reporting unit is less than its carrying amount prior to performing the two-step goodwill impairment test. If it is more-likely-than-not that the fair value of a reporting unit is less than its carrying amount, the two-step goodwill impairment test is required. If it is more-likely-than-not that the fair value of a reporting unit is greater than its carrying amount, the two-step goodwill impairment test is not required. For the year ended December 31, 2017 , we performed step one of the goodwill impairment test utilizing the market capitalization approach to determine whether the fair value of our reporting unit is less than its carrying amount. Based upon our assessment, we believe the fair value exceeds the carrying value, and no impairment loss was recorded in 2017 . Revenue and Deferred Revenue The Company generates revenue through delivery of its ecommerce fulfillment and marketing software solutions. The Company follows Financial Accounting Standards Board ("FASB") guidance set forth in Accounting Standards Codification ("ASC") Subtopic 985-605-05 related to Hosting Arrangements and ASC Subtopic 605-25 related to Revenue Arrangements with Multiple Deliverables . The Company recognizes revenue when all of the following conditions are met: there is persuasive evidence of an arrangement, the services have been delivered to the customer, the collection of the related fees is reasonably assured and the amount of the related fees is fixed and determinable. Revenue from new customer acquisition is generated under services agreements with multiple elements. Customers do not have the contractual right to take possession of our solutions. We evaluate each element in a multiple-element arrangement to determine whether it represents a separate unit of accounting. An element constitutes a separate unit of accounting when the delivered item has standalone value and delivery of the undelivered element is probable and within our control. Fees charged to customers based on the level of a customer's utilization of our solutions and other platform fees attributable to inventory management and third-party communication capabilities are recognized in the period in which such fees are earned. We recognize monthly subscription fees as revenue in the period in which the subscription is earned. Set-up fees provide customers access to our solutions through production launch. They are billed during the implementation phase and recorded as deferred revenue until a customer's subscription period has commenced. We also provide professional services to provide certain customer-requested enhancements to our solutions as well as other professional services. Set-up and professional services fees related to customer solution enhancements do not have stand-alone value because they are sold only in conjunction with a subscription to our solutions, they are sold only by us, a customer could not resell them, and they do not represent the culmination of a separate earnings process. Set-up fees without stand-alone value are recognized over the longer of the life of the agreement or the expected customer life. We recognize revenue for professional services fees charged to customers for solution enhancement services over the estimated remaining customer life. Professional services charged to customers that do have stand-alone value are recognized in the period in which the professional services fees are earned. In determining the estimated life of our customers, we consider our historical experience with customer contract renewals, the type of customer, the size of the customer and the period over which the customer will benefit from the related offerings. As of December 31, 2017 , the estimated life of certain customers ranges from 1 to 10 years , reflecting a shorter life for smaller customers and a longer life for our largest retail customers. Deferred revenue consists of the unearned portion of deferred set-up and professional services fees and annual subscription fees. Reimbursement payments received for out-of-pocket expenses are recorded as revenue and cost of revenue in the consolidated statements of comprehensive income (loss). Advertising Expenses The Company incurs advertising expense consisting of promotions and public relations to promote our solutions. Advertising is expensed as incurred and was $295 thousand , $100 thousand and $314 thousand for the years ended December 31, 2017 , 2016 and 2015 , respectively. Share-Based Compensation Share-based awards exchanged for employee services are recorded as expense, net of estimated forfeitures, at the estimated fair value of these awards over the requisite employee service period (typically with annual straight-line vesting over 4 years ), or where applicable for performance-based awards, over the service period, when the achievement of certain performance-based conditions are considered probable, and expire after 10 years . Pre-Spin-Off Valuation Inputs and Methodologies Prior to the Spin-Off, the Company's share-based awards consisted of CTI-issued stock options and stock appreciation rights ("SARs"), which were classified as liability awards and were included as a share-based compensation liability on the consolidated balance sheets. We estimated the fair value of these awards using a Black-Scholes pricing model. We measured the cost of services received in exchange for these awards based on the fair value of the award, and remeasured the fair value of the award at each reporting date. In valuing these share-based awards, significant judgment is required in determining the fair value of the Company's share price, the expected volatility of common stock and the expected term for which individuals will hold their share-based awards prior to exercise. The estimation of these awards that will ultimately vest requires judgment, and to the extent actual results differ from the Company's estimates, such amounts are recorded as an adjustment in the period in which estimates are revised. With the assistance of an independent third-party advisory firm, for the year ended December 31, 2015 and the three months ended March 31, 2016 , we estimated share-price based on an internal valuation using a combination of three different approaches: • Market Multiple Approach - this approach involves the capitalization of revenue and earnings before interest, taxes, depreciation and amortization, and option expense. Multiples are determined through an analysis of certain publicly traded companies, selected based on operational and economic similarity with the principal business and operational revenue model of CommerceHub. Multiples are calculated for the comparative companies based upon their trading prices. The risk analysis incorporates quantitative and qualitative risk factors, which relate to, among other things, the nature of the industry in which we and the other comparative companies are engaged, relative size, profitability and growth rates. • Guideline Transaction Approach - this approach is similar to the Market Multiple Approach in that it involves a consideration of multiples of revenue and Adjusted EBITDA. However, multiples used for this approach were determined through the analysis of transactions involving controlling interests in companies with operations similar to CommerceHub's business. • Discounted Cash Flow ("DCF") Approach - internally prepared financial projections are used to develop the DCF Approach, a valuation method that estimates the present value of the projected cash flows to be generated from the business. In the DCF Approach, a discount rate, reflecting all risks of ownership and associated risks of realizing the stream of projected future cash flows, is applied to the stream of projected cash flows. For the three months ended June 30, 2016 , the estimated share-price was based on the fair market value of our Series C common stock traded immediately following the Spin-Off. In connection with the Spin-Off, the outstanding CTI share-based awards were adjusted, such that each holder of an option award or a SAR with respect to shares of CTI common stock received an option award to purchase shares of our Series C common stock. Unlike the original CTI options and SARs, which were able to be settled in cash prior to completion of the Spin-Off, the new option awards resulting from the conversion of the original CTI options and SARs may be settled only in shares of our Series C common stock (see Note 12). Post-Spin-Off Valuation Inputs and Methodologies Following the Spin-Off, we grant to our employees stock options and restricted stock units ("RSUs") in respect of our Series C common stock under the CommerceHub, Inc. 2016 Omnibus Incentive Plan (as amended, amended and restated or otherwise modified from time to time, the "Omnibus Plan"), which was adopted in connection with the Spin-Off. The Company determined the fair value of RSU awards based on the closing market price per share of our Series C common stock on the date of grant. The Company estimates the fair value of stock options using a Black-Scholes pricing model. For awards granted subsequent to the Spin-Off, the share-price is based on the closing price of our Series C common stock on the date of grant. Expected volatility of the stock was based on our industry peer group because we did not have sufficient historical volatility data for our stock. The expected term of the options considers our historical and expected future employee exercise behavior and was determined using the simplified method, which was considered to be our best estimate of expected future term as we lacked sufficient history of exercise activity as a stand-alone public company. Further, our historical exercise experience is not considered to be representative of our future expected term based on the significant exercise activity that occurred in 2016 in anticipation of the Spin-Off. The risk-free interest rate assumption was based upon observed interest rates for constant maturity U.S. Treasury securities consistent with the expected term of the Company's share-based awards. The Company assumed a zero dividend yield as, following the Spin-Off, we do not expect to pay any cash dividends in the foreseeable future. The following table summarizes the assumptions used for estimating the fair value of stock options and SAR awards granted during the years ended December 31: 2017 2016 2016 2015 Risk-free interest rate 1.93% - 2.25% 1.36% - 2.27% 1.23% - 1.44% 1.76% Expected term (years) 6.3 6.3 5.9 - 6.3 5.3 - 6.2 Expected volatility 40.16% - 41.60% 41.51% - 41.89% 42.12% 30% - 31% Dividend yield —% —% —% —% Weighted average grant-date fair value $7.25 $6.22 $15.18 $14.13 The awards outstanding at the time of the Spin-Off were converted at an exchange ratio of approximately 2.18 , which reduced the underlying share price and resulting grant date fair value of awards granted after the Spin-Off. For awards granted prior to the Spin-Off, as these awards were classified as liability-based awards and were marked-to-market each reporting period, the weighted after grant date fair value in the table above represents the most recent marked-to-market fair value of such awards. The Company also grants employees rights to purchase discounted shares of our Series C common stock under the CommerceHub, Inc. 2016 Employee Stock Purchase Plan (as amended, amended and restated or otherwise modified from time to time, the "ESPP"). We estimate the fair value of ESPP rights based on the market price of our Series C common stock at the beginning of each offering period and the Black-Scholes option pricing model. The following table summarizes the assumptions used for estimating the fair value of ESPP rights granted during the year ended December 31, 2017 : Volatility 41.16% - 41.51% Term (in years) 0.5 Risk-free interest rate 0.82% - 1.17% Dividend yield —% The Company estimates the forfeiture rate for share-based awards based on our historical turnover experience and other qualitative factors. We review and update our forfeiture rate, if necessary, at least annually, or more frequently if facts or circumstances indicate a change is necessary or appropriate. Income Taxes Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the consolidated financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carry-forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the period that includes the enactment date. A tax valuation allowance is established, as needed, to reduce deferred tax assets to the amount expected to be realized. In the event it becomes more-likely-than-not that some or all of the deferred tax asset allowances will not be needed, the valuation allowance will be adjusted. In the ordinary course of business, there is inherent uncertainty in quantifying our income tax positions. We assess our income tax positions and record tax benefits for all years subject to examination based upon management's evaluation of the facts, circumstances and information available at the reporting date. For those tax positions where it is more-likely-than-not that a tax benefit will be sustained, we have determined the amount of the tax benefit to be recognized by estimating the largest amount of tax benefit that has a greater than 50% likelihood of being realized upon ultimate settlement with a taxing authority that has full knowledge of all relevant information. For those income tax positions where it is not more-likely-than-not that a tax benefit will be sustained, no tax benefit has been recognized in the financial statements. Interest and penalties related to unrecognized tax benefits are recognized as a component of income tax expense when settled. Business Combinations Assets acquired and liabilities assumed in a business combination are recognized at their estimated fair values as of the acquisition date. Transaction costs associated with a business combination are expensed as incurred. Any excess of the acquisition price over the estimated fair value of individually identifiable net assets acquired is recorded as goodwill. Assets acquired may also include identifiable intangible assets, such as subscriber relationships, which are recognized separately from goodwill. We make estimates and assumptions to value assets acquired and liabilities assumed at the acquisition date, including deferred income taxes, uncertain tax positions and tax-related valuation allowances. These estimates are inherently uncertain and subject to refinement, and they typically include the calculation of an appropriate discount rate and projection of the cash flows associated with each acquired asset. As a result, during the measurement period, which may be up to one year after the acquisition date, we may record adjustments to assets acquired and liabilities assumed with a corresponding offset to goodwill. Upon the conclusion of the one year measurement period or final determination of the values of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recorded to the consolidated statements of comprehensive income (loss).

Recent Accounting Pronouncement

Recent Accounting Pronouncements	12 Months Ended
	Dec. 31, 2017
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) ("ASU No. 2014-09"). This standard is effective for fiscal years beginning after December 15, 2017, with two transition methods of adoption allowed: a full retrospective or modified retrospective. In May 2016, FASB issued ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) . This update was issued to further clarify the implementation guidance on principal versus agent considerations in ASU No. 2014-09. In April 2016, FASB issued ASU No. 2016-10, Identifying Performance Obligations and Licensing , which clarifies implementation guidance on the identification of performance obligations and the licensing implementation guidance in ASU No. 2014-09. In May 2016, FASB issued ASU No. 2016-12, Narrow-Scope Improvements and Practical Expedients , which clarifies the guidance on assessing collectability, presentation of sales taxes, non-cash consideration and completed contracts and contract modifications at transition. In December 2016, FASB issued ASU No. 2016-20, Technical Corrections and Improvements to Topic 606 , which clarifies certain narrow aspects of ASU No. 2014-09. We continue to evaluate the impacts of this new standard on our business processes, information technology systems and associated internal controls. We have developed an implementation plan to adopt this standard, and, as part of this plan, we continue to assess the impacts this standard is expected to have on our financial statements and related disclosures. We will adopt this standard using the modified retrospective transition method effective January 1, 2018. The adoption of this standard will not significantly impact our recognition of order fee revenue and subscription and other platform revenue associated with our drop-ship and demand channel solutions. In addition, the adoption of this standard will impact our accounting for certain set-up and professional services revenue and the periods over which this revenue and the related deferred services costs are recognized. Further, this standard will impact how we account for costs to acquire a contract. We expect that applying this standard will result in the deferral of additional costs, including certain commission expenses to sales representatives directly associated with acquiring a new revenue contract, which we expect to recognize over the estimated customer life. We do not expect these impacts to set-up and professional services revenue and related deferred service costs and commissions will be significant to our consolidated financial statements. Based on our impact analysis performed to date, we estimate approximately a $0.3 million reduction to retained earnings upon the adoption of this standard on January 1, 2018. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) ("ASU No. 2016-02"). This topic provides that a lessee should recognize the assets and liabilities that arise from leases and requires an entity to separate the lease components from the non-lease components in a contract. ASU No. 2016-02 is intended to improve financial reporting on lease transactions and is effective for fiscal years beginning after December 15, 2018. We are evaluating the financial statement impact this update will have on our consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting ("ASU No. 2016-09"), which is intended to improve the accounting for share-based payment transactions as part of the FASB's simplification initiative. ASU No. 2016-09 changed aspects of the accounting for share-based payment award transactions, including: (1) accounting for income taxes; (2) classification of excess tax benefits on the statement of cash flows; (3) forfeitures; (4) minimum statutory tax withholding requirements; and (5) classification of employee taxes paid on the statement of cash flows when an employer withholds shares for tax-withholding purposes. We adopted ASU No. 2016-09 in the first quarter of 2017, which did not have a significant impact on our consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments (Topic 230) ("ASU No. 2016-15") , which addresses eight specific cash flow matters with the objective of reducing diversity in practice in how certain cash receipts and cash payments are classified in statements of cash flows. ASU No. 2016-15 is effective for fiscal years beginning after December 15, 2017. We are adopting ASU No. 2016-15 in the first quarter of 2018, which we do not expect to have a significant impact on our consolidated financial statements. In November 2016, the FASB issued ASU No. 2016-18, Restricted Cash ("ASU No. 2016-18") , which requires that entities show changes in total of cash, cash equivalents and restricted cash in the statement of cash flows. Transfers between cash, cash equivalents and restricted cash should not be presented as cash flow activities on the statement of cash flows. ASU No. 2016-18 is effective for fiscal years beginning after December 15, 2017. We are adopting ASU 2016-18 in the first quarter of 2018, which we do not expect to have a significant impact on the consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Accounting for Goodwill Impairment ("ASU No. 2017-04"), which removes Step 2 of the goodwill impairment test, which requires a hypothetical purchase price allocation. An impairment charge will now equal the amount by which the reporting unit's carrying value exceeds its fair value. ASU No. 2017-04 is effective for fiscal years beginning after December 15, 2019. We do not expect the adoption of this standard will have a significant impact on our consolidated financial statements. In May 2017, the FASB issued ASU No. 2017-09, Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting ("ASU No. 2017-09"), which clarifies what constitutes a modification of a share-based payment award. ASU No. 2017-09 is effective for fiscal years beginning after December 15, 2017. We are adopting ASU No. 2017-09 in the first quarter of 2018, which we do not expect to have a significant impact on the consolidated financial statements.

Earnings (Loss) Per Share

Earnings (Loss) Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings (Loss) Per Share	Earnings (Loss) Per Share For the years ended December 31, 2017 and 2016 , basic earnings per common share is computed by dividing net income by the weighted average number of common shares outstanding during that period (excluding pre-Spin-Off periods in 2016). For the year ended December 31, 2015 , basic and diluted earnings (loss) per common share is computed by dividing net income (loss) for the respective period by 42,702,842 common shares, which is the aggregate of 13,522,288 shares of Series A common stock, 711,992 shares Series B common stock and 28,468,562 shares of Series C common stock issued upon completion of the Spin-Off on July 22, 2016. The shares used in the calculation of diluted earnings (loss) per share for 2015 exclude issuances of 109,354 shares of common stock issued to pre-Spin-Off minority shareholders of CTI and 7,362,933 outstanding awards to purchase shares of our common stock, which occurred after the Spin-Off. Diluted earnings per share gives effect to all dilutive potential shares attributable to outstanding share-based awards during the applicable period. The shares used in the calculation of diluted earnings per share exclude options to purchase shares where the exercise price was greater than the average market price of such share for the period, awards where the effect of their inclusion would have an anti-dilutive effect, and awards with performance-based conditions where the performance criteria had not been met as of the reporting date. The following table sets forth net income (loss) and the basic and diluted shares used to calculate earnings per share (in thousands): Year Ended December 31, 2017 2016 2015 Net income (loss) $ 9,858 $ 9,096 $ (4,467 ) Basic - weighted average shares outstanding 43,204 42,831 42,703 Effect of dilutive potential securities 2,026 1,512 — Diluted - weighted average shares outstanding 45,230 44,343 42,703 Anti-dilutive securities 3,837 4,222 —

Business Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Business Combinations	Business Combinations On January 8, 2015, we acquired 100% of the shares of Mercent Corporation ("Mercent"), an online marketing technology and service company that helped merchants optimize performance across online channels, for total cash consideration of approximately $20.2 million , net of cash acquired. During the year ended December 31, 2015 , we incurred transaction-related costs of approximately $166 thousand , which are included in general and administrative expenses on the consolidated statements of comprehensive income (loss). Under the acquisition method of accounting, the Company allocated the purchase price to the identifiable assets and liabilities based on their estimated fair value, including customer relationships and developed software technology. Methodologies used in valuing the intangible assets included, but were not limited to, the multiple period excess earnings method for developed software technology and customer relationships. The excess of the purchase price over the total net identifiable assets has been recorded as goodwill, which includes synergies expected from the expanded service capabilities and the value of the assembled work force. For federal income tax purposes, the transaction is treated as a stock acquisition and the goodwill is no t deductible.

Concentrations of Significant C

Concentrations of Significant Customers and Credit Risk	12 Months Ended
	Dec. 31, 2017
Risks and Uncertainties [Abstract]
Concentrations of Significant Customers and Credit Risk	Concentrations of Significant Customers and Credit Risk No single customer accounted for more than 10% of our total revenue in any of the years ended December 31, 2017, 2016 or 2015. However, our revenue model is primarily based on retailer and supplier program relationships whereby many revenue-generating supplier transactions conducted through our platform may be attributable to a single retailer ("Total Program Revenue"). For the year ended December 31, 2017 , there were seven customers with Total Program Revenue that accounted for more than 5% each of our total revenue, two of which had Total Program Revenue that accounted for between 10% and 15% each of our total revenue. No customer represented more than 10% of accounts receivable at December 31, 2017 .

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Prior to the Spin-Off, Liberty, QVC, Inc. (“QVC”), which is a wholly owned subsidiary of Liberty, and other subsidiaries and equity investments of Liberty were related parties of CommerceHub for GAAP purposes and related persons of CommerceHub for purposes of Regulation S-K under the Securities Exchange Act of 1934, as amended. As a result, because this report includes pre-Spin-Off periods, we have disclosed activities with these entities during such periods. For the year ended December 31, 2017 and future periods that do not include pre-Spin-Off periods, based on current facts and circumstances, we do not expect Liberty, QVC or other subsidiaries or equity investments of Liberty to be related parties or related persons of CommerceHub, but we will continue to monitor and evaluate these relationships and other potential relationships with related parties and/or related persons. Transactions with QVC We provide our solutions to QVC in the ordinary course of business. For the years ended December 31, 2016 and 2015 , Total Program Revenue with QVC accounted for approximately 7% and 8% of total revenue, respectively. We had accounts receivable owing from QVC of approximately $784 thousand at December 31, 2016 . Transactions with Liberty In previous periods, we had outstanding a promissory note as a lender to Liberty, which carried an interest rate based on one-year LIBOR plus 100 basis points . In the years ended December 31, 2016 and 2015 , we earned interest of $273 thousand and $600 thousand on this promissory note, respectively. During the second quarter of 2016, Liberty fully repaid the $36.4 million outstanding under this promissory note, including accumulated interest of $2.4 million . During June 2016, we entered into a funding arrangement with Liberty pursuant to a previously established intercompany funding agreement. Under this arrangement, Liberty agreed to loan us $28.7 million , at current market interest rates, so we could fulfill our obligations under the predecessor plan to the CommerceHub, Inc. Legacy Stock Appreciation Rights Plan and our related liquidity program. In July 2016, we fully repaid amounts outstanding pursuant to this arrangement, including accumulated interest, to Liberty using borrowings under our credit facility, and the funding agreement between us and Liberty was terminated as of the completion of the Spin-Off. In July 2016, in conjunction with the Spin-Off, we collected amounts due from Liberty for federal tax benefits of $8.5 million and fully repaid amounts due for state taxes paid of $1.3 million . Further, we received a contribution from Liberty of $6.0 million to compensate the Company for the dilution associated with Parent equity awards, we paid a dividend of $18.9 million to the holders of CTI common stock, including Parent, as a return on investment, and we paid an additional dividend of $0.9 million to Parent, as the holder of CTI preferred shares. Amounts owed to Liberty of $33 thousand at December 31, 2016 are included in accounts payable and accrued expenses within the consolidated balance sheets.

Capitalized Software

Capitalized Software	12 Months Ended
	Dec. 31, 2017
Research and Development [Abstract]
Capitalized Software	Capitalized Software Capitalized software, net was comprised of the following at December 31 (in thousands): 2017 2016 Capitalized software $ 31,650 $ 32,506 Less accumulated amortization (28,800 ) (25,790 ) Capitalized software, net $ 2,850 $ 6,716 During 2017 , we recorded impairment charges totaling $254 thousand , included within cost of revenue in the consolidated statements of comprehensive income (loss), for capitalized software projects that will no longer be pursued. A portion of these charges was incurred in connection with our 2017 restructuring plan (see Note 16). Amortization expense related to capitalized software is included in cost of revenue and was approximately $4.9 million , $5.0 million and $3.4 million , for the years ended December 31, 2017 , 2016 and 2015 , respectively. Future amortization expense of existing capitalized software as of December 31, 2017 is expected to be as follows for the years ending December 31 (in thousands): 2018 $ 2,288 2019 477 2020 85 $ 2,850

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets There were no changes in the carrying amount of goodwill during the years ended December 31, 2017 and 2016 . Intangible assets acquired as of December 31, 2017 and 2016 were as follows (in thousands): Weighted Average Gross Carrying Accumulated Net Book Developed technology 2.0 $ 1,500 $ (1,500 ) $ — Customer relationships 2.0 2,000 (2,000 ) — Total $ 3,500 $ (3,500 ) $ — There was no amortization expense related to intangible assets acquired for the year ended December 31, 2017 and there was $1.8 million for each of the years ended December 31, 2016 and 2015 . Intangible assets acquired were fully amortized as of December 31, 2016 .

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment Property and equipment consisted of the following at December 31 (in thousands): 2017 2016 Computer equipment $ 14,068 $ 14,892 Furniture and fixtures 1,130 1,101 Leasehold improvements 3,028 2,965 Total 18,226 18,958 Less accumulated depreciation (12,160 ) (11,329 ) Property and equipment, net $ 6,066 $ 7,629 Depreciation of property and equipment totaled approximately $3.2 million , $3.0 million and $2.6 million during the years ended December 31, 2017 , 2016 and 2015 , respectively.

Share-Based Awards

Share-Based Awards	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Awards	Share-Based Awards We grant equity incentive awards to certain of our employees (including our executive officers), directors and consultants. Following the Spin-Off, all of the awards we have granted have been stock options and RSUs relating to shares of our Series C common stock. Most of these awards contain service-based vesting conditions (typically annual vesting over four years ), and some of these awards contain both service- and milestone-based vesting conditions. We also grant deferred stock units ("DSUs") in respect of our Series C common stock to our directors under the Omnibus Incentive Plan and the CommerceHub, Inc. Non-Employee Director Deferred Compensation Plan (the "Deferred Compensation Plan"). Included in the consolidated statements of comprehensive income (loss) are the following amounts of share-based compensation, net of estimated forfeitures, for the years ended December 31 (amounts in thousands): 2017 2016 2015 Cost of revenue $ 396 $ (102 ) $ 2,361 Research and development 1,728 2,261 7,229 Sales and marketing 553 834 4,098 General and administrative 5,952 8,297 28,462 $ 8,629 $ 11,290 $ 42,150 Gross tax-related benefits of $3.6 million , $87.2 million and $7.5 million were also recognized for the years ended December 31, 2017 , 2016 and 2015 , respectively. Cash received from exercises of stock options totaled $3.3 million , $0.8 million , and $33 thousand for the years ended December 31, 2017 , 2016 and 2015 , respectively, and is included in financing activities in the consolidated statements of cash flows. CommerceHub Employee Plans Legacy Plans Prior to the Spin-Off, CTI issued share-based awards pursuant to an incentive and nonqualified stock option plan adopted in 1999 (the "1999 Plan") and its 2010 Stock Appreciation Rights Plan (the "SAR Plan"). The 1999 Plan authorized grants of options to purchase up to 4,000,000 shares of authorized but unissued common stock. Options granted under the 1999 Plan were to vest over a period of four years and expire ten years from the date of grant. No shares of common stock are available for grants, or have been available for grants under the 1999 Plan, since September 2009 when the 1999 Plan expired. The SAR Plan authorized grants of up to 6,000,000 SARs, which included and was not in addition to shares previously issued, or shares issuable in respect of awards previously issued, under the 1999 Plan. The SARs issued under the SAR Plan typically vested over a period of four years and expired ten years from the date of grant for service-based awards. SARs that included both service and performance-based conditions vested based on the satisfaction of service requirements and achievement of performance conditions over the period specified in the applicable award agreement. The SAR Plan was terminated in connection with the Spin-Off. All of the Company's share-based awards under these plans were classified as liability awards, as the SARs could have been settled in cash and the stock options could have been settled in cash at the option of the holder, in each case under a liquidity program. The Company measured the cost of services received in exchange for a liability classified award based on the current fair value of the award, and remeasured the fair value of the award at each reporting date. In connection with the Spin-Off, the 2,663,616 CTI awards then outstanding, consisting of 33,950 options and 2,629,666 SARs, were converted at an exchange ratio of approximately 2.18 , into 5,811,150 options to purchase shares of our Series C common stock. Unlike the original CTI options and SARs, which were able to be settled in cash prior to completion of the Spin-Off, the option awards resulting from the conversion of the original CTI options and SARs may be settled only in shares of our Series C common stock. Except as described above, the terms of these awards (including, for example, the vesting terms thereof) are, in all material respects, the same as those of the corresponding original CTI option or SAR award. These awards were issued pursuant to the CommerceHub, Inc. Legacy Stock Option Plan and the CommerceHub, Inc. Legacy SAR Plan (together, the "Legacy Plans"). The Legacy Plans govern the terms and conditions of these option awards but will not be used to make any new grants following the Spin-Off. The foregoing conversion of these awards as part of our internal restructuring in connection with the Spin-Off resulted in a modification of the terms and conditions of the pre-Spin-Off awards, and the reclassification of the awards from liability to equity awards. As of the July 21, 2016 modification date, we performed a fair value analysis of the awards immediately before and immediately after the restructuring. Because the 1999 Plan and the SAR Plan contained antidilution provisions, there was no incremental fair value or compensation expense as a result of the restructuring. The fair value of these awards immediately before and immediately after the Spin-Off was approximately $12.5 million . The value of these awards at the time of the restructuring was reclassified from share-based compensation liability to additional paid in capital. The remaining unvested compensation expense is recognized over the remaining service period or, for those awards with performance-based conditions, the service period when such performance conditions are considered probable. CommerceHub, Inc. 2016 Omnibus Incentive Plan In connection with the Spin-Off, we adopted the Omnibus Plan. The Omnibus Plan is designed to provide additional remuneration to officers, employees, nonemployee directors and independent contractors for service to CommerceHub and to encourage each plan participant’s investment in CommerceHub. Stock options, SARs, restricted shares, restricted stock units, cash awards, performance awards or any combination of the foregoing may be granted under the Omnibus Plan (collectively, "awards"). On January 1, 2017, the number of shares available for issuance under the Omnibus Plan was increased by 2,146,064 shares, or 5.0% of the outstanding shares of our common stock on December 31, 2016 , to 15,346,064 shares of our Series C common stock, subject to anti-dilution, annual share-reserve increases and other adjustment provisions of the Omnibus Plan. The Omnibus Plan is administered by the compensation committee of the Company’s board of directors with regard to awards granted under the Omnibus Plan other than awards granted to the nonemployee directors, which are administered by the full board of directors, and the compensation committee and its designees (and the board of directors with respect to awards granted to non-employee directors) have full power and authority to determine the terms and conditions of such awards. We amended and restated the Omnibus Plan on October 13, 2016 in order to permit the compensation committee of the Company’s board of directors to delegate award granting authority under the Omnibus Plan. On June 16, 2017, our public stockholders approved the Second Amended and Restated Omnibus Plan at our 2017 Annual Meeting of Stockholders. Options Activity under the Omnibus Plan and Legacy Plans (Series C) The following tables summarize the share-based award activity of options to purchase shares of our common stock under our Omnibus Plan and Legacy Plans for the year ended December 31, 2017 : CommerceHub Employee Plans Omnibus Plan Legacy Plans Series C Weighted Average Exercise Price Series C Weighted Average Exercise Price Outstanding at January 1, 2017 193,998 $ 14.59 5,580,109 $ 12.96 Granted 364,075 $ 16.56 — $ — Exercised (3,544 ) $ 14.85 (205,963 ) $ 10.38 Forfeited (229,437 ) $ 15.68 (453,925 ) $ 15.53 Outstanding at December 31, 2017 325,092 $ 16.02 4,920,221 $ 12.83 Weighted average remaining contractual life (in years) 9.0 7.2 Aggregate intrinsic value (in thousands) $ 1,502 $ 38,187 Exercisable at December 31, 2017 28,274 $ 14.55 2,457,076 $ 9.61 Weighted average remaining contractual life (in years) 7.7 5.9 Aggregate intrinsic value (in thousands) $ 171 $ 26,978 Vested and expected to vest at December 31, 2017 285,180 $ 15.99 4,643,090 $ 12.62 Weighted average remaining contractual life (in years) 9.0 7.1 Aggregate intrinsic value (in thousands) $ 1,325 $ 36,999 The aggregate intrinsic value of options exercised under the Omnibus Plan during 2017 was $23 thousand . There were no exercises under the Omnibus Plan during 2016. We do not issue new grants under the Legacy Plans. The aggregate intrinsic value of options exercised under the Legacy Plans was $1.7 million during 2017 and $0.5 million during the post-Spin-Off period in 2016 . The aggregate intrinsic value of options exercised under the 1999 Plan and the SAR Plan was $86.7 million during the pre-Spin-Off period in 2016 and $7.5 million during the year ended December 31, 2015 . As of December 31, 2017 , unrecognized compensation cost related to options to purchase shares of our Series C common stock under the Omnibus Plan and Legacy Plans was approximately $1.4 million and $9.9 million , respectively, and is expected to be recognized over weighted-average remaining vesting periods of approximately 3.2 years and 2.6 years , respectively. RSU Activity Under the Omnibus Plan (Series C) The following table summarizes the share-based award activity of RSUs relating to our Series C common stock granted under the Omnibus Plan for the year ended December 31, 2017 : Number of Weighted Outstanding at January 1, 2017 505,831 $ 14.35 Granted 442,263 $ 17.31 Vested (123,645 ) $ 14.34 Forfeited (280,954 ) $ 15.36 Outstanding at December 31, 2017(1) 543,495 $ 16.15 (1) Includes 40,850 DSUs relating to our Series C common stock issued to our directors. These DSUs are vested, but the underlying shares of Series C common stock will not be issued until delivery pursuant to the Deferred Compensation Plan. The weighted average grant-date fair value of RSUs granted under the Omnibus Plan during 2016 was $14.35 . The total fair value as of the respective vesting dates of RSUs vested during 2017 was $2.3 million and there were no RSUs vested for both years ended December 31, 2016 and 2015 . As of December 31, 2017 , unrecognized compensation cost in respect of RSUs relating to shares of Series C common stock was approximately $4.3 million and is expected to be recognized over a weighted average remaining vesting period of approximately 2.8 years . CommerceHub, Inc. Employee Stock Purchase Plan In connection with the Spin-Off, we also adopted the ESPP, which provides employees with the opportunity to invest a portion of their annual eligible compensation to purchase shares of our Series C common stock at a purchase price equal to 85% of the lower of (a) the fair market value of our Series C common stock at the beginning of the applicable six-month offering period, and (b) the fair market value of our Series C common stock at the end of the applicable six-month offering period. We originally reserved 900,000 shares of our Series C common stock for issuance under the ESPP, which was increased to 1,329,212 shares on January 1, 2017 and is increased annually on the first day of each calendar year by the lesser of one percent of our total outstanding common stock on the last day of the immediately preceding calendar year or such other amount determined by the plan administrator. The first offering period under the ESPP began on January 1, 2017. For the year ended December 31, 2017 , we recorded approximately $302 thousand of share-based compensation expense associated with the ESPP. During 2017 , employees purchased 36,298 shares of Series C common stock under the ESPP and total cash received from ESPP purchases was $464 thousand . Liberty Employee Plans In connection with the Spin-Off, holders of option awards, RSUs and restricted stock awards ("RSAs") relating to Liberty's Liberty Ventures common stock received CommerceHub options, RSUs and RSAs, respectively, pursuant to the CommerceHub, Inc. Transitional Stock Adjustment Plan (the “Transitional Plan”). The Transitional Plan, which is administered for the benefit of Liberty employees and consultants, governs the terms and conditions of these new awards but will not be used to make any further grants. CommerceHub, Inc. Transitional Stock Adjustment Plan Prior to the Spin-Off, Liberty had granted to certain directors, officers, employees and consultants of Liberty options to purchase shares of Liberty Ventures common stock (each, an "original Ventures option award") pursuant to applicable incentive plans in place at Liberty. Each holder of an outstanding original Ventures option award on the record date for the Spin-Off (the "record date") who was a member of the Liberty board of directors or an officer of Liberty holding the position of Vice President or above received (i) an option to purchase shares of the corresponding series of our common stock and an option to purchase shares of our Series C common stock (such new option awards, "new CommerceHub option awards") and (ii) an adjustment to the exercise price of and the number of shares subject to the original Ventures option award (as so adjusted, an "adjusted Ventures option award"). The exercise prices of and the number of shares subject to the new CommerceHub option awards and the related adjusted Ventures option awards were determined based on the exercise price of and the number of shares subject to the applicable original Ventures option award, the distribution ratios used in the Spin-Off, the pre-Spin-Off trading price of Liberty Ventures common stock (determined using the volume weighted average price of the applicable series of Liberty Ventures common stock over the three consecutive trading days immediately preceding the Spin-Off) and the relative post-Spin-Off trading prices of Liberty Ventures common stock and our common stock (determined using the volume-weighted average price of the applicable series of common stock over the three consecutive trading days beginning on the first trading day following the Spin-Off on which both the Liberty Ventures common stock and our common stock traded in the "regular way" (meaning once the common stock trades using a standard settlement cycle)), such that the pre-Spin-Off intrinsic value of the original Ventures option awards was allocated between the new CommerceHub option awards and the adjusted Ventures option awards. All other holders of original Ventures option awards did not receive any new CommerceHub option awards as a result of the distribution. Rather, the holders' original Ventures option awards were adjusted so as to preserve the pre-Spin-Off intrinsic value of the original Ventures option awards based on the exercise price of and number of shares subject to such original Ventures option awards, the distribution ratios used in the Spin-Off, the pre-Spin-Off trading price of Liberty Ventures common stock and the post-Spin-Off trading price of Liberty Ventures common stock (determined as described above). Except as described above, all other terms of the adjusted Ventures option awards and the new CommerceHub option awards (including, for example, the vesting terms thereof) are, in all material respects, the same as those of the corresponding original Ventures option awards. Options Activity Under the Transitional Plan (Series A and Series C) The following table summarizes the share-based award activity of options to purchase shares of our common stock under the Transitional Plan for the year ended December 31, 2017 : Liberty Employee Plans Transitional Plan Series A Weighted Average Exercise Price Series C Weighted Average Exercise Price Outstanding at January 1, 2017 329,188 $ 7.46 1,006,043 $ 8.93 Granted — $ — — $ — Exercised (61,248 ) $ 5.63 (136,220 ) $ 5.62 Forfeited (1,785 ) $ 12.51 (3,558 ) $ 12.46 Outstanding and expected to vest at December 31, 2017 266,155 $ 7.90 866,265 $ 9.45 Weighted average remaining contractual life (in years) 3.0 3.5 Aggregate intrinsic value (in thousands) $ 3,733 $ 9,650 Exercisable at December 31, 2017 203,611 $ 6.44 460,899 $ 7.23 Weighted average remaining contractual life (in years) 2.3 2.6 Aggregate intrinsic value (in thousands) $ 3,149 $ 6,159 We do not issue new grants under the Transitional Plan. The aggregate intrinsic value of options to purchase Series A common stock exercised under the Transitional Plan was $0.7 million during 2017 and $0.1 million during the post-Spin-Off period in 2016. The aggregate intrinsic value of options to purchase Series C common stock exercised under the Transitional Plan was $1.5 million during 2017 and $0.2 million during the post-Spin-Off period in 2016. There is no unrecognized compensation cost related to stock options under the Transitional Plan because they are held by employees of Liberty and any related compensation expense is incurred by Liberty. Options Activity Under the Transitional Plan (Series B) As of December 31, 2017, there were 172,882 new CommerceHub option awards to purchase shares of our Series B common stock outstanding, with a weighted average exercise price of $11.89 , aggregate intrinsic value of $2.0 million , and weighted average remaining contractual life of 4.2 years . There was no activity relating to these awards during the year ended December 31, 2017 . As of December 31, 2017, 32,052 of these stock options were exercisable, with a weighted average exercise price of $12.49 , aggregate intrinsic value of $353 thousand and weighted average remaining contractual life of 4.9 years . There is no unrecognized compensation cost related to options to purchase shares of our Series B common stock under the Transitional Plan because these awards are held by an employee of Liberty and any related compensation expense is incurred by Liberty. RSAs and RSUs Under the Transitional Plan Each holder of an RSU relating to shares of Series A or Series B Liberty Ventures common stock (an "original Ventures RSU") on the record date received 0.1 of an RSU relating to shares of the corresponding series of CommerceHub common stock and 0.2 of an RSU relating to shares of CommerceHub Series C common stock (such new RSU awards, "new CommerceHub RSUs") for each original Ventures RSU held by them as of the record date, with cash paid in lieu of fractional new CommerceHub RSUs. Except as described herein, the terms of all of the new CommerceHub RSUs (including, for example, the vesting terms thereof) are, in all material respects, the same as those of the corresponding original Ventures RSU. Each holder of an RSA relating to shares of Series A or Series B Liberty Ventures common stock (an "original Ventures RSA") on the record date received (i) 0.1 of an RSA relating to the corresponding series of CommerceHub common stock and (ii) 0.2 of an RSA relating to CommerceHub Series C common stock (such new RSAs, "new CommerceHub RSAs") for each RSA relating to Liberty Ventures common stock held by them as of the record date, with cash paid in lieu of fractional new CommerceHub RSAs. Except as described herein, the terms of all new CommerceHub RSAs (including, for example, the vesting terms thereof) are, in all material respects, the same as those of the corresponding original Ventures RSA. RSA and RSU Activity Under the Transitional Plan (Series A and Series C) Share-based award activity for RSUs and RSAs relating to our Series A and Series C common stock issued under the Transitional Plan for the year ended December 31, 2017 was not material. As of December 31, 2017, there were 4,357 RSAs and 118 RSUs relating to our Series A common stock outstanding, and there were 8,745 RSAs and 236 RSUs relating to our Series C common stock outstanding. There is no unrecognized compensation cost related to these awards because they are held by employees of Liberty and any related compensation expense is incurred by Liberty.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For pre-Spin-Off periods, CTI was part of the Liberty federal consolidated tax group, and federal income taxes were paid to (or refunded by) Liberty pursuant to the terms of a tax sharing agreement under which taxes were computed on a separate company basis. Following the Spin-Off, CommerceHub is a separate, stand-alone federal taxpayer. The tax provision included in these consolidated financial statements has been prepared on a stand-alone basis, as if CommerceHub was not part of the Liberty consolidated group. Accordingly, the effective tax rate of the Company in future years could vary from its historical effective tax rates depending on, among other factors, the Company's legal structure and related tax elections from time to time. Liberty filed income tax returns in the U.S. federal jurisdiction, various state jurisdictions and the United Kingdom. In the normal course of business, Liberty is subject to examination by various taxing authorities. All tax years prior to 2015 are closed. Liberty's 2015 and 2016 tax years are being examined currently under the IRS's Compliance Assurance Process ("CAP") program. The 2015 and 2016 examinations are substantially complete and are expected to be formally closed in the first quarter of 2018. The statute of limitations periods in the applicable state jurisdictions vary, but generally expire three to four years from the due date or filing of the tax return. Beginning with the 2016 post-Spin-Off period and for subsequent periods, CommerceHub files income tax returns in the U.S. federal jurisdiction, various state jurisdictions and the United Kingdom. CommerceHub has historically filed stand-alone income tax returns in various state jurisdictions and has expanded the list of states in the post-Spin-Off period. In the normal course of business, CommerceHub is subject to examination by various taxing authorities. CommerceHub's 2016 post-Spin-Off tax return is currently "open" and is not eligible to participate in the CAP program. The statute of limitations periods in the various state jurisdictions in which CommerceHub historically filed stand-alone income tax returns vary, but generally expire three to four years from the due date or filing of the tax return. Income tax expense (benefit) consists of the following at December 31 (in thousands): 2017 2016 2015 Current Federal $ 10,884 $ (11,497 ) $ 7,931 State and local 1,411 (2,674 ) 2,477 Foreign 10 7 — Total current 12,305 (14,164 ) 10,408 Deferred Federal 2,815 15,869 (9,942 ) State and local 756 5,457 (2,347 ) Total deferred 3,571 21,326 (12,289 ) Total tax expense (benefit) $ 15,876 $ 7,162 $ (1,881 ) There were no uncertain tax positions as of December 31, 2017 or December 31, 2016 . There were no accrued interest or penalties recognized in the consolidated balance sheet as of December 31, 2017 and December 31, 2016 . Income tax expense differed from the amounts computed by applying the U.S. federal income tax rate of 35% to income (loss) before taxes as a result of the following for the years ended December 31 (in thousands): 2017 2016 2015 Computed "expected" tax expense $ 9,007 $ 5,690 $ (2,222 ) Increase (decrease) resulting from: Impact of the Tax Act on deferred tax assets 3,161 — — Section 162(m) adjustment 3,276 — — State tax law change — 1,524 — State and local income taxes, net of federal income tax benefit 852 284 (21 ) Impact of state rate change on deferred taxes 293 — 105 Non-deductible expenses 21 66 228 Excess share-based compensation deduction (157 ) — — Market adjustment for options exercised — 127 319 Write-off federal NOL — 122 — Research and development tax credits (559 ) (649 ) (368 ) Other (18 ) (2 ) 78 Total tax expense (benefit) $ 15,876 $ 7,162 $ (1,881 ) The increase in income tax expense was due to increased pre-tax book income of $25.7 million in the year ended December 31, 2017 as compared to pre-tax book income of $16.3 million in 2016. In addition, the U.S. Tax Cuts and Jobs Act ("Tax Act") was enacted on December 22, 2017 and introduces significant changes to U.S. income tax law. Effective in 2018, the Tax Act reduces the U.S. statutory tax rate from 35% to 21%, among other changes. Accordingly, we have adjusted our deferred income taxes as of December 22, 2017 to reflect the reduced rate that will apply in future periods when these deferred taxes are settled or realized, which resulted in a deferred tax expense of $3.2 million . In addition, actual income tax expense for the year ended December 31, 2017 was greater than the federal income tax rate of 35% due to an immaterial error correction recorded in 2017 associated with limitations on deductions under Section 162(m) of the Internal Revenue Code (the “IRC”) with respect to certain share-based compensation awards granted prior to the Spin-Off, which limit the Company’s future deductions on these share-based compensation awards in our stand-alone provision beginning at the Spin-Off. The Company did not appropriately reflect these Section 162(m) limitations on our deferred tax asset at the time of the Spin-Off in 2016. As a result, fiscal 2016 deferred income tax expense was understated by approximately $3.3 million , with a corresponding overstatement of deferred tax assets. The $3.3 million effect of this error was corrected in the fourth quarter of 2017 and is incorporated in our 2017 tax expense and included in the “Section 162(m) adjustment” in the table above. Furthermore, the increase in income tax expense in 2016 as compared to the benefit in 2015 is primarily due to pre-tax book income of $16.3 million in 2016 as compared to a pre-tax book loss of $6.3 million in 2015. In 2016, actual income tax expense was greater than the amounts computed by applying the U.S. federal income tax rate of 35% , primarily due to an immaterial error correction recorded in 2016 associated with a change in tax law in New York State (“NY”). This tax law change, which was enacted in 2014 and effective in 2015, revised the method used to determine NY apportionment. We did not appropriately update the NY apportionment rate to reflect the impact of this law change in 2014. The $1.5 million net effect of this error was corrected in the fourth quarter of 2016 and is incorporated in our 2016 income tax expense, and included in “State tax law change” in the table above. Based on our assessment of the quantitative and qualitative factors, these errors and related impacts, both individually and in the aggregate, were not considered material to the consolidated financial statements for any periods in which these errors originated, and correction of these errors was not considered material to our 2016 or 2017 consolidated financial statements. The write-off of federal net operating loss carryforwards ("NOLs") is the result of forfeiting one year of IRC Section 382 limitations described below and NOLs in conjunction with the Spin-Off, as both the pre- and post-Spin-Off periods in 2016 count against the available number of periods, while the amount of NOLs we are limited to in 2016 does not change. The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities are presented below (in thousands) at December 31 : 2017 2016 Deferred tax assets: Accounts receivable allowances $ 268 $ 75 Deferred revenue 1,695 2,721 Accrued liabilities 965 426 Shared-based compensation 3,106 5,948 Net operating loss 1,852 3,999 Other 59 1 Total deferred tax assets 7,945 13,170 Deferred tax liabilities: Software and deferred costs 1,909 4,372 Property and equipment 238 1,084 Total gross deferred tax liabilities 2,147 5,456 Net deferred tax asset $ 5,798 $ 7,714 In assessing the realizability of deferred tax assets, management considers whether it is more-likely-than-not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Management considered the scheduled reversal of deferred tax liabilities and projected future taxable income in making this assessment. Based upon the level of projections for future taxable income over the periods in which the deferred tax assets are deductible, management believes it is more-likely-than-not that the Company will realize the benefits of these deductible differences. During the year ended December 31, 2016, the exercise of a significant portion of share-based compensation awards created a tax deductible expense, and reduced our deferred tax asset related to share-based compensation awards by $31.3 million . The deductions generated estimated gross federal NOLs of approximately $74.7 million . As allowed under the tax sharing agreement between the Company and Liberty entered into prior to the Spin-Off, $49.1 million of these NOLs were utilized to refund federal income taxes paid to Liberty in the prior two tax years. In accordance with the same tax sharing agreement, subject to finalizing our 2016 pre-Spin-Off federal tax return, the estimated remaining federal NOLs of $25.6 million were forfeited and recorded as an equity distribution to Liberty upon the Spin-Off in 2016. During the year ended December 31, 2017, upon finalizing our consolidated federal returns for the pre-spin period, we adjusted the amount of remaining gross federal NOLs we ultimately forfeited to Liberty. The adjustment totaled $5.1 million , which was recorded as an equity distribution to Liberty in 2017 and is included in the change in additional paid-in capital on our consolidated balances sheets for 2017. As of December 31, 2017 , we had unused federal NOLs that were acquired as part of the Mercent acquisition. Under IRC Section 382, if it is determined that, due to transactions involving CommerceHub's shares owned by its 5 percent or greater shareholders, a change of ownership has occurred under the provisions of IRC Section 382, our federal NOLs could be subject to IRC Section 382 limitations. Based on studies of the changes in ownership of Mercent at acquisition, we have determined that IRC Section 382 ownership changes did occur, which limit the amount of NOLs that can be used in future years. As of December 31, 2017 , we had a total of $7.9 million in unused NOLs, of which approximately $1.5 million of NOLs are available to be utilized each year from 2018 to 2019, and approximately $350 thousand of NOLs are available to be utilized each year from 2020 to 2033.

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt On June 28, 2016, we entered into a credit agreement governing a $125.0 million revolving credit facility, which expires on June 28, 2021. At December 31, 2017 , we had no borrowings and no letters of credit outstanding under the facility, and our available borrowings under the facility were $125.0 million . The fair value of the debt under our credit facility, which holds a floating interest rate of a short duration and is based on Level 2 valuation inputs, approximates the carrying value when a balance is outstanding. Interest on the revolving credit facility is based on a base rate or Eurodollar rate plus an applicable margin that increases as our total leverage ratio increases, with the base rate margin ranging from 0.75% to 1.25% and the Eurodollar rate margin ranging from 1.75% to 2.25% . The revolving credit facility also carries a commitment fee on the unused portion that increases as our total leverage ratio increases, ranging from 0.25% to 0.50% per annum. In conjunction with entering into this credit facility, we incurred charges totaling $1.1 million . These charges are included in other long-term assets on the consolidated balance sheets and are recognized over the term of the credit facility. Borrowings under the credit facility are collateralized by substantially all of our assets. The credit agreement contains covenants and restrictions which, among other things, require the maintenance of certain financial ratios, including a total leverage ratio and an interest coverage ratio, and restrict dividend payments and the incurrence of certain indebtedness and other activities, including acquisitions and dispositions. We were in compliance with these covenants and restrictions as of December 31, 2017 .

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings From time to time, we may become involved in various lawsuits and legal proceedings which arise in the ordinary course of business. We are currently not aware of any such legal proceedings or claims that we believe will have, individually or in the aggregate, a material adverse effect on our business, prospects, financial condition, results of operations and/or cash flows. Leases The Company leases its corporate offices and primary operations facility under an operating lease arrangement which expires in March 2022, with renewal provisions that allow the Company to extend the lease through March 2028. We also lease office facilities in Seattle, Washington and shared office and executive office facilities in Hertford, England. During the first quarter of 2017 , we entered into a new lease for office space in Seattle, Washington and, at the same time, entered into a sub-lease of our existing space in Seattle. During the second quarter of 2017, we vacated our previous office and moved into the new office space and, as a result, recognized an impairment charge equal to the fair value of the unrecovered payments for the remainder of the lease, which was not material. Total rent expense for the Company's office space for the years ended December 31, 2017 , 2016 and 2015 was $2.0 million , $1.9 million and $1.4 million , respectively. Future minimum lease payments due under operating lease arrangements contain rent increases over the term of the lease. Rent expense on these operating leases is recognized over the term of the lease on a straight-line basis. The excess of rent expense over future minimum lease payments due totaled $2.5 million and $1.1 million at December 31, 2017 and 2016 , respectively, and is included in other long-term liabilities on the consolidated balance sheets. At December 31, 2017 , contractual minimum payments under operating leases were as follows (in thousands): Year Ending December 31, 2018 $ 2,652 2019 2,201 2020 2,183 2021 2,139 2022 362 Total minimum lease payments (1) $ 9,537 (1) Total minimum payments under our operating leases exclude $2.4 million in rental income from sub-tenants, consisting of $0.6 million due in each of the respective years ending December 31, 2018 through 2021.

Restructuring

Restructuring	12 Months Ended
	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Restructuring	Restructuring In September 2017, we commenced a plan to consolidate our software development team and certain other corporate activities into our Albany, NY headquarters to more effectively support the ongoing growth of our business by streamlining and centralizing operations (the "2017 restructuring plan"). The 2017 restructuring plan included the immediate reduction of certain positions in our Seattle, WA office, the retention of certain Seattle-based engineers for a transition period, the gradual replacement of many of those positions in Albany, and the long-term presence of a Seattle-based account services team dedicated to brands and marketplace customers. In connection with the 2017 restructuring plan, we recognized charges for termination benefits during the year ended December 31, 2017 . The 2017 restructuring plan also includes retention benefits for employees who stay with the Company, which will be earned and paid out based on time-based milestones, with the last payments expected to occur in January 2019. As a result, the expenses related to these retention incentives will be recorded ratably over each employee’s applicable retention period. As of December 31, 2017 , we estimate that the total expenses associated with the 2017 restructuring plan will be approximately $6.0 million , of which $2.3 million was recognized in 2017, with the remaining expenses primarily being recognized throughout 2018. This estimate includes future expenses expected to be incurred from termination and retention benefits accrued over the retention period as well as payroll and related costs for redundant positions as we transition our software development team and certain other corporate activities into our Albany, NY headquarters, but which does not take into account actual and expected cost savings from reduced headcount associated with the 2017 restructuring plan. During the year ended December 31, 2017 , we incurred $2.3 million in restructuring charges within the consolidated statements of comprehensive income (loss) as follows (amounts in thousands): Cost of Revenue Research and Development Sales and Marketing General and Administrative Total Restructuring Expenses Termination & retention benefits $ 295 $ 1,345 $ 384 $ 64 $ 2,088 Impairment of capitalized software 191 — — — 191 Total restructuring expenses $ 486 $ 1,345 $ 384 $ 64 $ 2,279 The table below sets forth our restructuring liability during the year ended December 31, 2017 (in thousands): Total Restructuring Liability Balance at January 1, 2017 $ — Restructuring charges 2,088 Non-cash adjustments — Cash payouts (812 ) Balance at December 31, 2017 $ 1,276 Our total restructuring liability of $1.3 million consists of accruals for termination and retention benefits. We expect $0.5 million of these benefits will be paid within the next 12 months, and this portion is included in accounts payable and accrued expenses within the consolidated balance sheets. The remaining $0.8 million of these benefits, which we expect to fully pay by the first quarter of 2019, is included in other long-term liabilities within the consolidated balance sheets.

Selected Quarterly Information

Selected Quarterly Information (unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Information (unaudited)	Selected Quarterly Information (unaudited) Three Months Ended, March 31, 2017 June 30, 2017 September 30, 2017 December 31, 2017 (in thousands, except per share amounts) Revenue $ 24,568 $ 25,208 $ 24,614 $ 36,731 Gross profit 19,052 19,569 19,586 31,314 Income from operations 4,267 3,841 3,318 15,040 Net income $ 2,459 $ 2,245 $ 1,988 $ 3,166 Earnings per share: Basic $ 0.06 $ 0.05 $ 0.05 $ 0.07 Diluted $ 0.06 $ 0.05 $ 0.04 $ 0.07 Three Months Ended, March 31, 2016 June 30, 2016 September 30, 2016 December 31, 2016 (in thousands, except per share amounts) Revenue $ 22,090 $ 23,103 $ 22,478 $ 32,881 Gross profit 15,985 17,783 16,741 26,986 Income (loss) from operations (3,026 ) 7,280 633 11,805 Net income (loss) $ (1,990 ) $ 4,424 $ 710 $ 5,952 Earnings (loss) per share:* Basic $ (0.04 ) $ 0.10 $ 0.02 $ 0.14 Diluted $ (0.04 ) $ 0.10 $ 0.02 $ 0.13 * Share count for pre-Spin-Off periods represent the shares issued at Spin-Off on July 22, 2016.

Significant Accounting Polici24

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements include the accounts of CommerceHub and its subsidiaries. All intercompany accounts and transactions have been eliminated in the consolidated financial statements, which have been prepared in conformity with U.S. generally accepted accounting principles ("GAAP").
Use of Estimates	Use of Estimates Preparing these consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates and assumptions.
Segment and Geographical Information	Segment and Geographic Information Operating segments are components of our business for which discrete financial information is available and evaluated by the chief operating decision maker ("CODM") for purposes of allocating resources and evaluating financial performance. Our Chief Executive Officer, who is our CODM, reviews the Company's consolidated financial information results to allocate resources and evaluate performance. As such, the Company operates as a single segment.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid securities with original maturities of 90 days or less to be cash equivalents, including bank and money market accounts. Cash and cash equivalents at December 31, 2017 consisted principally of cash and money market accounts held at financial institutions in the United States that management believes to be reputable. Cash and cash equivalents at December 31, 2016 consisted principally of cash held at such financial institutions. At times, our accounts exceed insured limits.
Accounts Receivable and Allowance for Doubtful Accounts	Accounts Receivable and Allowance for Doubtful Accounts The Company grants credit to customers in the normal course of business without collateral. Accounts receivable are stated net of allowances for doubtful accounts, which represent estimated losses resulting from the inability of certain customers to make the required payments. When determining the allowances for doubtful accounts, we take several factors into consideration, including the overall composition of the accounts receivable aging, our prior history of accounts receivable write-offs, the types of customers and our experience with specific customers. We write off accounts receivable when they are determined to be uncollectible. Changes in the allowances for doubtful accounts are recorded as bad debt expense and are included in general and administrative expenses in our consolidated statements of comprehensive income (loss).
Property and Equipment	Property and Equipment Property and equipment are stated at cost. Equipment under capital leases are stated at the present value of minimum lease payments. Repairs and maintenance costs are expensed as incurred. Depreciation of property and equipment is computed using the straight-line method over the following estimated useful lives: Computer equipment 3 to 5 years Furniture and fixtures 5 years Leasehold improvements lesser of remaining lease term or estimated useful life
Capitalized Software Costs	Capitalized Software Costs The Company capitalizes the cost of payroll, payroll-related costs and third-party consulting fees incurred in the direct development or enhancement of solutions as internal-use software. During 2016 , we changed and further refined our methodologies and processes to estimate the portion of software development costs that is eligible to be capitalized, which is assessed at a project level. Development costs incurred during the preliminary project stage or costs incurred for requirements gathering, data conversion activities, training, maintenance and minor enhancements are expensed as incurred. Development costs incurred for the coding, configuration, interfacing, automation and testing of new functionality after the preliminary project stage is complete are capitalized. Capitalized software costs are amortized on a straight-line basis over two to three years, based on the nature and estimated useful life of the applicable solution. Amortization of capitalized software costs is included in cost of revenue within the consolidated statements of comprehensive income (loss).
Deferred Services Costs	Deferred Services Costs The Company defers direct payroll, payroll-related costs and third-party consulting costs incurred for the set-up and integration of new customers on our platform and for enhancements we make to our platform that are particular to specific customers. Deferred services costs associated with the integration of customers on our platform are recognized over the estimated life of such customers. Deferred services costs incurred to enhance existing customers' platforms are recognized over the estimated remaining customer life. Amortization of deferred services costs is included in cost of revenue within the consolidated statements of comprehensive income (loss).
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets Long-lived assets, such as property and equipment, capitalized software costs, deferred services costs and intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset or asset group to be tested for possible impairment, the Company first compares undiscounted cash flows expected to be generated by that asset or asset group to its carrying value. If the carrying value of the long-lived asset or asset group is not recoverable on an undiscounted cash flow basis, an impairment is recognized to the extent that the carrying value exceeds its fair value. Fair value may be determined through various valuation techniques, including discounted cash flow models, quoted market values and independent third-party appraisals, as considered necessary or appropriate.
Goodwill	Goodwill Goodwill is an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Goodwill is reviewed for impairment at least annually as of October 1, and more frequently if events or changes in circumstances indicate that goodwill might be impaired. GAAP provides the option to perform a qualitative assessment to determine whether it is more-likely-than-not that the fair value of a reporting unit is less than its carrying amount prior to performing the two-step goodwill impairment test. If it is more-likely-than-not that the fair value of a reporting unit is less than its carrying amount, the two-step goodwill impairment test is required. If it is more-likely-than-not that the fair value of a reporting unit is greater than its carrying amount, the two-step goodwill impairment test is not required. For the year ended December 31, 2017 , we performed step one of the goodwill impairment test utilizing the market capitalization approach to determine whether the fair value of our reporting unit is less than its carrying amount.
Revenue and Deferred Revenue	Revenue and Deferred Revenue The Company generates revenue through delivery of its ecommerce fulfillment and marketing software solutions. The Company follows Financial Accounting Standards Board ("FASB") guidance set forth in Accounting Standards Codification ("ASC") Subtopic 985-605-05 related to Hosting Arrangements and ASC Subtopic 605-25 related to Revenue Arrangements with Multiple Deliverables . The Company recognizes revenue when all of the following conditions are met: there is persuasive evidence of an arrangement, the services have been delivered to the customer, the collection of the related fees is reasonably assured and the amount of the related fees is fixed and determinable. Revenue from new customer acquisition is generated under services agreements with multiple elements. Customers do not have the contractual right to take possession of our solutions. We evaluate each element in a multiple-element arrangement to determine whether it represents a separate unit of accounting. An element constitutes a separate unit of accounting when the delivered item has standalone value and delivery of the undelivered element is probable and within our control. Fees charged to customers based on the level of a customer's utilization of our solutions and other platform fees attributable to inventory management and third-party communication capabilities are recognized in the period in which such fees are earned. We recognize monthly subscription fees as revenue in the period in which the subscription is earned. Set-up fees provide customers access to our solutions through production launch. They are billed during the implementation phase and recorded as deferred revenue until a customer's subscription period has commenced. We also provide professional services to provide certain customer-requested enhancements to our solutions as well as other professional services. Set-up and professional services fees related to customer solution enhancements do not have stand-alone value because they are sold only in conjunction with a subscription to our solutions, they are sold only by us, a customer could not resell them, and they do not represent the culmination of a separate earnings process. Set-up fees without stand-alone value are recognized over the longer of the life of the agreement or the expected customer life. We recognize revenue for professional services fees charged to customers for solution enhancement services over the estimated remaining customer life. Professional services charged to customers that do have stand-alone value are recognized in the period in which the professional services fees are earned. In determining the estimated life of our customers, we consider our historical experience with customer contract renewals, the type of customer, the size of the customer and the period over which the customer will benefit from the related offerings. As of December 31, 2017 , the estimated life of certain customers ranges from 1 to 10 years , reflecting a shorter life for smaller customers and a longer life for our largest retail customers. Deferred revenue consists of the unearned portion of deferred set-up and professional services fees and annual subscription fees. Reimbursement payments received for out-of-pocket expenses are recorded as revenue and cost of revenue in the consolidated statements of comprehensive income (loss).
Advertising Expenses	Advertising Expenses The Company incurs advertising expense consisting of promotions and public relations to promote our solutions. Advertising is expensed as incurred
Share-Based Compensation	Share-Based Compensation Share-based awards exchanged for employee services are recorded as expense, net of estimated forfeitures, at the estimated fair value of these awards over the requisite employee service period (typically with annual straight-line vesting over 4 years ), or where applicable for performance-based awards, over the service period, when the achievement of certain performance-based conditions are considered probable, and expire after 10 years . Pre-Spin-Off Valuation Inputs and Methodologies Prior to the Spin-Off, the Company's share-based awards consisted of CTI-issued stock options and stock appreciation rights ("SARs"), which were classified as liability awards and were included as a share-based compensation liability on the consolidated balance sheets. We estimated the fair value of these awards using a Black-Scholes pricing model. We measured the cost of services received in exchange for these awards based on the fair value of the award, and remeasured the fair value of the award at each reporting date. In valuing these share-based awards, significant judgment is required in determining the fair value of the Company's share price, the expected volatility of common stock and the expected term for which individuals will hold their share-based awards prior to exercise. The estimation of these awards that will ultimately vest requires judgment, and to the extent actual results differ from the Company's estimates, such amounts are recorded as an adjustment in the period in which estimates are revised. With the assistance of an independent third-party advisory firm, for the year ended December 31, 2015 and the three months ended March 31, 2016 , we estimated share-price based on an internal valuation using a combination of three different approaches: • Market Multiple Approach - this approach involves the capitalization of revenue and earnings before interest, taxes, depreciation and amortization, and option expense. Multiples are determined through an analysis of certain publicly traded companies, selected based on operational and economic similarity with the principal business and operational revenue model of CommerceHub. Multiples are calculated for the comparative companies based upon their trading prices. The risk analysis incorporates quantitative and qualitative risk factors, which relate to, among other things, the nature of the industry in which we and the other comparative companies are engaged, relative size, profitability and growth rates. • Guideline Transaction Approach - this approach is similar to the Market Multiple Approach in that it involves a consideration of multiples of revenue and Adjusted EBITDA. However, multiples used for this approach were determined through the analysis of transactions involving controlling interests in companies with operations similar to CommerceHub's business. • Discounted Cash Flow ("DCF") Approach - internally prepared financial projections are used to develop the DCF Approach, a valuation method that estimates the present value of the projected cash flows to be generated from the business. In the DCF Approach, a discount rate, reflecting all risks of ownership and associated risks of realizing the stream of projected future cash flows, is applied to the stream of projected cash flows. For the three months ended June 30, 2016 , the estimated share-price was based on the fair market value of our Series C common stock traded immediately following the Spin-Off. In connection with the Spin-Off, the outstanding CTI share-based awards were adjusted, such that each holder of an option award or a SAR with respect to shares of CTI common stock received an option award to purchase shares of our Series C common stock. Unlike the original CTI options and SARs, which were able to be settled in cash prior to completion of the Spin-Off, the new option awards resulting from the conversion of the original CTI options and SARs may be settled only in shares of our Series C common stock (see Note 12). Post-Spin-Off Valuation Inputs and Methodologies Following the Spin-Off, we grant to our employees stock options and restricted stock units ("RSUs") in respect of our Series C common stock under the CommerceHub, Inc. 2016 Omnibus Incentive Plan (as amended, amended and restated or otherwise modified from time to time, the "Omnibus Plan"), which was adopted in connection with the Spin-Off. The Company determined the fair value of RSU awards based on the closing market price per share of our Series C common stock on the date of grant. The Company estimates the fair value of stock options using a Black-Scholes pricing model. For awards granted subsequent to the Spin-Off, the share-price is based on the closing price of our Series C common stock on the date of grant. Expected volatility of the stock was based on our industry peer group because we did not have sufficient historical volatility data for our stock. The expected term of the options considers our historical and expected future employee exercise behavior and was determined using the simplified method, which was considered to be our best estimate of expected future term as we lacked sufficient history of exercise activity as a stand-alone public company. Further, our historical exercise experience is not considered to be representative of our future expected term based on the significant exercise activity that occurred in 2016 in anticipation of the Spin-Off. The risk-free interest rate assumption was based upon observed interest rates for constant maturity U.S. Treasury securities consistent with the expected term of the Company's share-based awards.
Income Taxes	Income Taxes Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the consolidated financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carry-forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the period that includes the enactment date. A tax valuation allowance is established, as needed, to reduce deferred tax assets to the amount expected to be realized. In the event it becomes more-likely-than-not that some or all of the deferred tax asset allowances will not be needed, the valuation allowance will be adjusted. In the ordinary course of business, there is inherent uncertainty in quantifying our income tax positions. We assess our income tax positions and record tax benefits for all years subject to examination based upon management's evaluation of the facts, circumstances and information available at the reporting date. For those tax positions where it is more-likely-than-not that a tax benefit will be sustained, we have determined the amount of the tax benefit to be recognized by estimating the largest amount of tax benefit that has a greater than 50% likelihood of being realized upon ultimate settlement with a taxing authority that has full knowledge of all relevant information. For those income tax positions where it is not more-likely-than-not that a tax benefit will be sustained, no tax benefit has been recognized in the financial statements. Interest and penalties related to unrecognized tax benefits are recognized as a component of income tax expense when settled.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) ("ASU No. 2014-09"). This standard is effective for fiscal years beginning after December 15, 2017, with two transition methods of adoption allowed: a full retrospective or modified retrospective. In May 2016, FASB issued ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) . This update was issued to further clarify the implementation guidance on principal versus agent considerations in ASU No. 2014-09. In April 2016, FASB issued ASU No. 2016-10, Identifying Performance Obligations and Licensing , which clarifies implementation guidance on the identification of performance obligations and the licensing implementation guidance in ASU No. 2014-09. In May 2016, FASB issued ASU No. 2016-12, Narrow-Scope Improvements and Practical Expedients , which clarifies the guidance on assessing collectability, presentation of sales taxes, non-cash consideration and completed contracts and contract modifications at transition. In December 2016, FASB issued ASU No. 2016-20, Technical Corrections and Improvements to Topic 606 , which clarifies certain narrow aspects of ASU No. 2014-09. We continue to evaluate the impacts of this new standard on our business processes, information technology systems and associated internal controls. We have developed an implementation plan to adopt this standard, and, as part of this plan, we continue to assess the impacts this standard is expected to have on our financial statements and related disclosures. We will adopt this standard using the modified retrospective transition method effective January 1, 2018. The adoption of this standard will not significantly impact our recognition of order fee revenue and subscription and other platform revenue associated with our drop-ship and demand channel solutions. In addition, the adoption of this standard will impact our accounting for certain set-up and professional services revenue and the periods over which this revenue and the related deferred services costs are recognized. Further, this standard will impact how we account for costs to acquire a contract. We expect that applying this standard will result in the deferral of additional costs, including certain commission expenses to sales representatives directly associated with acquiring a new revenue contract, which we expect to recognize over the estimated customer life. We do not expect these impacts to set-up and professional services revenue and related deferred service costs and commissions will be significant to our consolidated financial statements. Based on our impact analysis performed to date, we estimate approximately a $0.3 million reduction to retained earnings upon the adoption of this standard on January 1, 2018. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) ("ASU No. 2016-02"). This topic provides that a lessee should recognize the assets and liabilities that arise from leases and requires an entity to separate the lease components from the non-lease components in a contract. ASU No. 2016-02 is intended to improve financial reporting on lease transactions and is effective for fiscal years beginning after December 15, 2018. We are evaluating the financial statement impact this update will have on our consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting ("ASU No. 2016-09"), which is intended to improve the accounting for share-based payment transactions as part of the FASB's simplification initiative. ASU No. 2016-09 changed aspects of the accounting for share-based payment award transactions, including: (1) accounting for income taxes; (2) classification of excess tax benefits on the statement of cash flows; (3) forfeitures; (4) minimum statutory tax withholding requirements; and (5) classification of employee taxes paid on the statement of cash flows when an employer withholds shares for tax-withholding purposes. We adopted ASU No. 2016-09 in the first quarter of 2017, which did not have a significant impact on our consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments (Topic 230) ("ASU No. 2016-15") , which addresses eight specific cash flow matters with the objective of reducing diversity in practice in how certain cash receipts and cash payments are classified in statements of cash flows. ASU No. 2016-15 is effective for fiscal years beginning after December 15, 2017. We are adopting ASU No. 2016-15 in the first quarter of 2018, which we do not expect to have a significant impact on our consolidated financial statements. In November 2016, the FASB issued ASU No. 2016-18, Restricted Cash ("ASU No. 2016-18") , which requires that entities show changes in total of cash, cash equivalents and restricted cash in the statement of cash flows. Transfers between cash, cash equivalents and restricted cash should not be presented as cash flow activities on the statement of cash flows. ASU No. 2016-18 is effective for fiscal years beginning after December 15, 2017. We are adopting ASU 2016-18 in the first quarter of 2018, which we do not expect to have a significant impact on the consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Accounting for Goodwill Impairment ("ASU No. 2017-04"), which removes Step 2 of the goodwill impairment test, which requires a hypothetical purchase price allocation. An impairment charge will now equal the amount by which the reporting unit's carrying value exceeds its fair value. ASU No. 2017-04 is effective for fiscal years beginning after December 15, 2019. We do not expect the adoption of this standard will have a significant impact on our consolidated financial statements. In May 2017, the FASB issued ASU No. 2017-09, Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting ("ASU No. 2017-09"), which clarifies what constitutes a modification of a share-based payment award. ASU No. 2017-09 is effective for fiscal years beginning after December 15, 2017. We are adopting ASU No. 2017-09 in the first quarter of 2018, which we do not expect to have a significant impact on the consolidated financial statements.
Business Combinations	Business Combinations Assets acquired and liabilities assumed in a business combination are recognized at their estimated fair values as of the acquisition date. Transaction costs associated with a business combination are expensed as incurred. Any excess of the acquisition price over the estimated fair value of individually identifiable net assets acquired is recorded as goodwill. Assets acquired may also include identifiable intangible assets, such as subscriber relationships, which are recognized separately from goodwill. We make estimates and assumptions to value assets acquired and liabilities assumed at the acquisition date, including deferred income taxes, uncertain tax positions and tax-related valuation allowances. These estimates are inherently uncertain and subject to refinement, and they typically include the calculation of an appropriate discount rate and projection of the cash flows associated with each acquired asset. As a result, during the measurement period, which may be up to one year after the acquisition date, we may record adjustments to assets acquired and liabilities assumed with a corresponding offset to goodwill. Upon the conclusion of the one year measurement period or final determination of the values of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recorded to the consolidated statements of comprehensive income (loss).

Basis of Presentation (Tables)

Basis of Presentation (Tables)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of revenues by type	During the year ended December 31, 2017, we updated the way in which we present revenue by type. The table below provides revenue by type for previously reported periods under our current presentation. For the three months ended: 9/30/2017 6/30/2017 3/31/2017 12/31/2016 9/30/2016 6/30/2016 3/31/2016 12/31/2015 9/30/2015 6/30/2015 3/31/2015 Revenue by type: Core drop-ship revenue: Order fee revenue $ 12,276 $ 12,901 $ 12,038 $ 19,569 $ 10,900 $ 11,227 $ 10,399 $ 17,070 $ 9,414 $ 9,683 $ 9,102 Subscription and other platform revenue 8,544 8,432 8,451 9,195 8,053 7,827 7,542 7,728 6,767 6,529 6,474 Set-up and professional services revenue 1,713 1,622 1,725 1,387 1,431 1,491 1,383 1,238 1,106 1,055 894 Total core drop-ship revenue 22,533 22,955 22,214 30,151 20,384 20,545 19,324 26,036 17,287 17,267 16,470 Demand channel revenue 2,081 2,253 2,354 2,730 2,094 2,558 2,766 3,235 2,408 2,591 2,320 Total $ 24,614 $ 25,208 $ 24,568 $ 32,881 $ 22,478 $ 23,103 $ 22,090 $ 29,271 $ 19,695 $ 19,858 $ 18,790 Year Ended December 31, 2017 2016 2015 Revenue: Core Drop-Ship Revenue Order fee revenue $ 59,788 $ 52,095 $ 45,269 Subscription and other platform revenue 35,224 32,617 27,498 Set-up and professional services revenue 7,047 5,692 4,293 Total core drop-ship revenue 102,059 90,404 77,060 Demand channel revenue 9,062 10,148 10,554 Total revenue $ 111,121 $ 100,552 $ 87,614

Significant Accounting Polici26

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Schedule of Allowance for Doubtful Accounts Activity	Our allowance for doubtful accounts activity, included in accounts receivable, net, was as follows for the years ended December 31, (in thousands): 2017 2016 2015 Balances as of January 1 $ 200 $ 239 $ 233 Provision for doubtful accounts 1,269 629 481 Write-offs (385 ) (668 ) (475 ) Balances as of December 31 $ 1,084 $ 200 $ 239
Summary of the Useful Lives of Property and Equipment	Depreciation of property and equipment is computed using the straight-line method over the following estimated useful lives: Computer equipment 3 to 5 years Furniture and fixtures 5 years Leasehold improvements lesser of remaining lease term or estimated useful life Property and equipment consisted of the following at December 31 (in thousands): 2017 2016 Computer equipment $ 14,068 $ 14,892 Furniture and fixtures 1,130 1,101 Leasehold improvements 3,028 2,965 Total 18,226 18,958 Less accumulated depreciation (12,160 ) (11,329 ) Property and equipment, net $ 6,066 $ 7,629
Summary of Assumptions for Estimating Fair Value of Awards Granted	The following table summarizes the assumptions used for estimating the fair value of stock options and SAR awards granted during the years ended December 31: 2017 2016 2016 2015 Risk-free interest rate 1.93% - 2.25% 1.36% - 2.27% 1.23% - 1.44% 1.76% Expected term (years) 6.3 6.3 5.9 - 6.3 5.3 - 6.2 Expected volatility 40.16% - 41.60% 41.51% - 41.89% 42.12% 30% - 31% Dividend yield —% —% —% —% Weighted average grant-date fair value $7.25 $6.22 $15.18 $14.13
Summary of Assumptions Used to Estimate the Value of ESPP Awards Granted	The following table summarizes the assumptions used for estimating the fair value of ESPP rights granted during the year ended December 31, 2017 : Volatility 41.16% - 41.51% Term (in years) 0.5 Risk-free interest rate 0.82% - 1.17% Dividend yield —%

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule of Income (Loss) and Basic and Diluted Shares	The following table sets forth net income (loss) and the basic and diluted shares used to calculate earnings per share (in thousands): Year Ended December 31, 2017 2016 2015 Net income (loss) $ 9,858 $ 9,096 $ (4,467 ) Basic - weighted average shares outstanding 43,204 42,831 42,703 Effect of dilutive potential securities 2,026 1,512 — Diluted - weighted average shares outstanding 45,230 44,343 42,703 Anti-dilutive securities 3,837 4,222 —

Capitalized Software (Tables)

Capitalized Software (Tables)	12 Months Ended
	Dec. 31, 2017
Research and Development [Abstract]
Schedule of capitalized software costs	Capitalized software, net was comprised of the following at December 31 (in thousands): 2017 2016 Capitalized software $ 31,650 $ 32,506 Less accumulated amortization (28,800 ) (25,790 ) Capitalized software, net $ 2,850 $ 6,716 Intangible assets acquired as of December 31, 2017 and 2016 were as follows (in thousands): Weighted Average Gross Carrying Accumulated Net Book Developed technology 2.0 $ 1,500 $ (1,500 ) $ — Customer relationships 2.0 2,000 (2,000 ) — Total $ 3,500 $ (3,500 ) $ —
Schedule of future amortization expense	Future amortization expense of existing capitalized software as of December 31, 2017 is expected to be as follows for the years ending December 31 (in thousands): 2018 $ 2,288 2019 477 2020 85 $ 2,850

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of intangible assets	Capitalized software, net was comprised of the following at December 31 (in thousands): 2017 2016 Capitalized software $ 31,650 $ 32,506 Less accumulated amortization (28,800 ) (25,790 ) Capitalized software, net $ 2,850 $ 6,716 Intangible assets acquired as of December 31, 2017 and 2016 were as follows (in thousands): Weighted Average Gross Carrying Accumulated Net Book Developed technology 2.0 $ 1,500 $ (1,500 ) $ — Customer relationships 2.0 2,000 (2,000 ) — Total $ 3,500 $ (3,500 ) $ —

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Schedule of property and equipment	Depreciation of property and equipment is computed using the straight-line method over the following estimated useful lives: Computer equipment 3 to 5 years Furniture and fixtures 5 years Leasehold improvements lesser of remaining lease term or estimated useful life Property and equipment consisted of the following at December 31 (in thousands): 2017 2016 Computer equipment $ 14,068 $ 14,892 Furniture and fixtures 1,130 1,101 Leasehold improvements 3,028 2,965 Total 18,226 18,958 Less accumulated depreciation (12,160 ) (11,329 ) Property and equipment, net $ 6,066 $ 7,629

Share-Based Awards (Tables)

Share-Based Awards (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Compensation Allocation	Included in the consolidated statements of comprehensive income (loss) are the following amounts of share-based compensation, net of estimated forfeitures, for the years ended December 31 (amounts in thousands): 2017 2016 2015 Cost of revenue $ 396 $ (102 ) $ 2,361 Research and development 1,728 2,261 7,229 Sales and marketing 553 834 4,098 General and administrative 5,952 8,297 28,462 $ 8,629 $ 11,290 $ 42,150
Options and SARs Activity	The following tables summarize the share-based award activity of options to purchase shares of our common stock under our Omnibus Plan and Legacy Plans for the year ended December 31, 2017 : CommerceHub Employee Plans Omnibus Plan Legacy Plans Series C Weighted Average Exercise Price Series C Weighted Average Exercise Price Outstanding at January 1, 2017 193,998 $ 14.59 5,580,109 $ 12.96 Granted 364,075 $ 16.56 — $ — Exercised (3,544 ) $ 14.85 (205,963 ) $ 10.38 Forfeited (229,437 ) $ 15.68 (453,925 ) $ 15.53 Outstanding at December 31, 2017 325,092 $ 16.02 4,920,221 $ 12.83 Weighted average remaining contractual life (in years) 9.0 7.2 Aggregate intrinsic value (in thousands) $ 1,502 $ 38,187 Exercisable at December 31, 2017 28,274 $ 14.55 2,457,076 $ 9.61 Weighted average remaining contractual life (in years) 7.7 5.9 Aggregate intrinsic value (in thousands) $ 171 $ 26,978 Vested and expected to vest at December 31, 2017 285,180 $ 15.99 4,643,090 $ 12.62 Weighted average remaining contractual life (in years) 9.0 7.1 Aggregate intrinsic value (in thousands) $ 1,325 $ 36,999
Schedule of RSU activity	The following table summarizes the share-based award activity of RSUs relating to our Series C common stock granted under the Omnibus Plan for the year ended December 31, 2017 : Number of Weighted Outstanding at January 1, 2017 505,831 $ 14.35 Granted 442,263 $ 17.31 Vested (123,645 ) $ 14.34 Forfeited (280,954 ) $ 15.36 Outstanding at December 31, 2017(1) 543,495 $ 16.15 (1) Includes 40,850 DSUs relating to our Series C common stock issued to our directors. These DSUs are vested, but the underlying shares of Series C common stock will not be issued until delivery pursuant to the Deferred Compensation Plan.
Stock Option Activity	The following table summarizes the share-based award activity of options to purchase shares of our common stock under the Transitional Plan for the year ended December 31, 2017 : Liberty Employee Plans Transitional Plan Series A Weighted Average Exercise Price Series C Weighted Average Exercise Price Outstanding at January 1, 2017 329,188 $ 7.46 1,006,043 $ 8.93 Granted — $ — — $ — Exercised (61,248 ) $ 5.63 (136,220 ) $ 5.62 Forfeited (1,785 ) $ 12.51 (3,558 ) $ 12.46 Outstanding and expected to vest at December 31, 2017 266,155 $ 7.90 866,265 $ 9.45 Weighted average remaining contractual life (in years) 3.0 3.5 Aggregate intrinsic value (in thousands) $ 3,733 $ 9,650 Exercisable at December 31, 2017 203,611 $ 6.44 460,899 $ 7.23 Weighted average remaining contractual life (in years) 2.3 2.6 Aggregate intrinsic value (in thousands) $ 3,149 $ 6,159

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of components of income tax expense (benefit)	Income tax expense (benefit) consists of the following at December 31 (in thousands): 2017 2016 2015 Current Federal $ 10,884 $ (11,497 ) $ 7,931 State and local 1,411 (2,674 ) 2,477 Foreign 10 7 — Total current 12,305 (14,164 ) 10,408 Deferred Federal 2,815 15,869 (9,942 ) State and local 756 5,457 (2,347 ) Total deferred 3,571 21,326 (12,289 ) Total tax expense (benefit) $ 15,876 $ 7,162 $ (1,881 )
Schedule of effective income tax rate reconciliation	Income tax expense differed from the amounts computed by applying the U.S. federal income tax rate of 35% to income (loss) before taxes as a result of the following for the years ended December 31 (in thousands): 2017 2016 2015 Computed "expected" tax expense $ 9,007 $ 5,690 $ (2,222 ) Increase (decrease) resulting from: Impact of the Tax Act on deferred tax assets 3,161 — — Section 162(m) adjustment 3,276 — — State tax law change — 1,524 — State and local income taxes, net of federal income tax benefit 852 284 (21 ) Impact of state rate change on deferred taxes 293 — 105 Non-deductible expenses 21 66 228 Excess share-based compensation deduction (157 ) — — Market adjustment for options exercised — 127 319 Write-off federal NOL — 122 — Research and development tax credits (559 ) (649 ) (368 ) Other (18 ) (2 ) 78 Total tax expense (benefit) $ 15,876 $ 7,162 $ (1,881 )
Schedule of deferred tax assets and liabilities	The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities are presented below (in thousands) at December 31 : 2017 2016 Deferred tax assets: Accounts receivable allowances $ 268 $ 75 Deferred revenue 1,695 2,721 Accrued liabilities 965 426 Shared-based compensation 3,106 5,948 Net operating loss 1,852 3,999 Other 59 1 Total deferred tax assets 7,945 13,170 Deferred tax liabilities: Software and deferred costs 1,909 4,372 Property and equipment 238 1,084 Total gross deferred tax liabilities 2,147 5,456 Net deferred tax asset $ 5,798 $ 7,714

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of future minimum payments under operating leases	At December 31, 2017 , contractual minimum payments under operating leases were as follows (in thousands): Year Ending December 31, 2018 $ 2,652 2019 2,201 2020 2,183 2021 2,139 2022 362 Total minimum lease payments (1) $ 9,537 (1) Total minimum payments under our operating leases exclude $2.4 million in rental income from sub-tenants, consisting of $0.6 million due in each of the respective years ending December 31, 2018 through 2021.

Restructuring (Tables)

Restructuring (Tables)	12 Months Ended
	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Schedule of Restructuring Charges	During the year ended December 31, 2017 , we incurred $2.3 million in restructuring charges within the consolidated statements of comprehensive income (loss) as follows (amounts in thousands): Cost of Revenue Research and Development Sales and Marketing General and Administrative Total Restructuring Expenses Termination & retention benefits $ 295 $ 1,345 $ 384 $ 64 $ 2,088 Impairment of capitalized software 191 — — — 191 Total restructuring expenses $ 486 $ 1,345 $ 384 $ 64 $ 2,279
Schedule of Restructuring Liability	The table below sets forth our restructuring liability during the year ended December 31, 2017 (in thousands): Total Restructuring Liability Balance at January 1, 2017 $ — Restructuring charges 2,088 Non-cash adjustments — Cash payouts (812 ) Balance at December 31, 2017 $ 1,276

Selected Quarterly Informatio35

Selected Quarterly Information (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Selected quarterly information (unaudited)	Three Months Ended, March 31, 2017 June 30, 2017 September 30, 2017 December 31, 2017 (in thousands, except per share amounts) Revenue $ 24,568 $ 25,208 $ 24,614 $ 36,731 Gross profit 19,052 19,569 19,586 31,314 Income from operations 4,267 3,841 3,318 15,040 Net income $ 2,459 $ 2,245 $ 1,988 $ 3,166 Earnings per share: Basic $ 0.06 $ 0.05 $ 0.05 $ 0.07 Diluted $ 0.06 $ 0.05 $ 0.04 $ 0.07 Three Months Ended, March 31, 2016 June 30, 2016 September 30, 2016 December 31, 2016 (in thousands, except per share amounts) Revenue $ 22,090 $ 23,103 $ 22,478 $ 32,881 Gross profit 15,985 17,783 16,741 26,986 Income (loss) from operations (3,026 ) 7,280 633 11,805 Net income (loss) $ (1,990 ) $ 4,424 $ 710 $ 5,952 Earnings (loss) per share:* Basic $ (0.04 ) $ 0.10 $ 0.02 $ 0.14 Diluted $ (0.04 ) $ 0.10 $ 0.02 $ 0.13 * Share count for pre-Spin-Off periods represent the shares issued at Spin-Off on July 22, 2016.

Basis of Presentation - Segment

Basis of Presentation - Segment and Geographic Information (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Concentration Risk [Line Items]
Order fee revenue													$ 59,788	$ 52,095	$ 45,269
Subscription and other platform revenue													35,224	32,617	27,498
Set-up and professional services revenue													7,047	5,692	4,293
Total core drop-ship revenue													102,059	90,404	77,060
Demand channel revenue													9,062	10,148	10,554
Total revenue	$ 36,731	$ 24,614	$ 25,208	$ 24,568	$ 32,881	$ 22,478	$ 23,103	$ 22,090					$ 111,121	$ 100,552	$ 87,614
UNITED STATES | Sales Revenue, Net | Geographic concentration risk
Concentration Risk [Line Items]
Concentration risk, percentage													96.00%	96.00%	96.00%
Scenario, Previously Reported
Concentration Risk [Line Items]
Order fee revenue		12,276	12,901	12,038	19,569	10,900	11,227	10,399	$ 17,070	$ 9,414	$ 9,683	$ 9,102
Subscription and other platform revenue		8,544	8,432	8,451	9,195	8,053	7,827	7,542	7,728	6,767	6,529	6,474
Set-up and professional services revenue		1,713	1,622	1,725	1,387	1,431	1,491	1,383	1,238	1,106	1,055	894
Total core drop-ship revenue		22,533	22,955	22,214	30,151	20,384	20,545	19,324	26,036	17,287	17,267	16,470
Demand channel revenue		2,081	2,253	2,354	2,730	2,094	2,558	2,766	3,235	2,408	2,591	2,320
Total revenue		$ 24,614	$ 25,208	$ 24,568	$ 32,881	$ 22,478	$ 23,103	$ 22,090	$ 29,271	$ 19,695	$ 19,858	$ 18,790

Significant Accounting Polici37

Significant Accounting Policies - Accounts Receivable and Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for Doubtful Accounts Receivable [Roll Forward]
Allowance for doubtful accounts, beginning balance	$ 200	$ 239	$ 233
Provision for doubtful accounts	1,269	629	481
Write-offs	(385)	(668)	(475)
Allowance for doubtful accounts, ending balance	$ 1,084	$ 200	$ 239

Significant Accounting Polici38

Significant Accounting Policies - Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2017
Computer equipment | Minimum
Property, Plant and Equipment [Line Items]
Property equipment useful lives	3 years
Computer equipment | Maximum
Property, Plant and Equipment [Line Items]
Property equipment useful lives	5 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property equipment useful lives	5 years

Significant Accounting Polici39

Significant Accounting Policies - Capitalized Software Costs and Goodwill (Details)	12 Months Ended
	Dec. 31, 2017USD ($)
Finite-Lived Intangible Assets [Line Items]
Goodwill impairment loss	$ 0
Developed software technology | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated life of intangible assets	2 years
Developed software technology | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated life of intangible assets	3 years

Significant Accounting Polici40

Significant Accounting Policies - Revenue and Deferred Revenue (Details)	12 Months Ended
	Dec. 31, 2017
Minimum
Deferred Revenue Arrangement [Line Items]
Customer life	1 year
Maximum
Deferred Revenue Arrangement [Line Items]
Customer life	10 years

Significant Accounting Polici41

Significant Accounting Policies - Advertising Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Advertising expense	$ 295	$ 100	$ 314

Significant Accounting Polici42

Significant Accounting Policies - Share-based Compensation (Details)	5 Months Ended	7 Months Ended	12 Months Ended
	Dec. 31, 2016$ / shares	Jul. 22, 2016$ / shares	Dec. 31, 2017$ / shares	Dec. 31, 2015$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award requisite service period			4 years
Expiration period			10 years
Dividend yield			0.00%
Spinoff transaction, exchange ratio		2.18
Options and SARs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate minimum	1.36%	1.23%	1.93%
Risk-free interest rate maximum	2.27%	1.44%	2.25%
Risk-free interest rate				1.76%
Expected term of awards	6 years 3 months 19 days		6 years 3 months 19 days
Expected volatility, minimum	41.51%		40.16%	30.00%
Expected volatility, maximum	41.89%		41.60%	31.00%
Expected volatility		42.12%
Dividend yield	0.00%	0.00%	0.00%	0.00%
Weighted average grant date fair value (in USD per share)	$ 6.22	$ 15.18	$ 7.25	$ 14.13
Options and SARs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term of awards		5 years 10 months 25 days		5 years 3 months 18 days
Options and SARs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term of awards		6 years 3 months 19 days		6 years 2 months 12 days

Significant Accounting Polici43

Significant Accounting Policies - ESPP Valuation Assumptions (Details)	12 Months Ended
	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility, minimum	41.16%
Expected volatility, maximum	41.51%
Expected term of awards	6 months
Risk-free interest rate minimum	0.82%
Risk-free interest rate maximum	1.17%
Dividend yield	0.00%

Recent Accounting Pronounceme44

Recent Accounting Pronouncements Recent Accounting Pronouncement - Details (Details) - USD ($) $ in Thousands	Jan. 01, 2018	Dec. 31, 2017	Dec. 31, 2016
Subsequent Event [Line Items]
Decrease in retained earnings as a result of new accounting standard adoption		$ (23,103)	$ (13,245)
Accounting Standards Update 2014-09 | Pro Forma | Difference between Revenue Guidance in Effect before and after Topic 606
Subsequent Event [Line Items]
Decrease in retained earnings as a result of new accounting standard adoption	$ 300

Earnings (Loss) Per Share - Nar

Earnings (Loss) Per Share - Narrative (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted average number of shares outstanding (in shares)			42,702,842
Anti-dilutive securities (in shares)	3,837,000	4,222,000	0
Common stock issuable to pre-Spin-Off minority shareholders of CTI
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Anti-dilutive securities (in shares)			109,354
Stock options
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Anti-dilutive securities (in shares)			7,362,933
Common Series A
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted average number of shares outstanding (in shares)			13,522,288
Common Series B
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted average number of shares outstanding (in shares)			711,992
Common Series C
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted average number of shares outstanding (in shares)			28,468,562

Earnings (Loss) Per Share - Sch

Earnings (Loss) Per Share - Schedule Of Earnings Per Share (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net income (loss)	$ 3,166	$ 1,988	$ 2,245	$ 2,459	$ 5,952	$ 710	$ 4,424	$ (1,990)	$ 9,858	$ 9,096	$ (4,467)
Basic - weighted average shares outstanding (in shares)									43,204	42,831	42,703
Effect of dilutive potential securities (in shares)									2,026	1,512	0
Diluted - weighted average shares outstanding (in shares)									45,230	44,343	42,703
Anti-dilutive securities (in shares)									3,837	4,222	0

Business Combinations (Details)

Business Combinations (Details) - USD ($)	Jan. 08, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Cash consideration		$ 0	$ 0	$ 20,225,000
Mercent
Business Acquisition [Line Items]
Percentage of voting interests acquired	100.00%
Cash consideration	$ 20,200,000
Transaction related costs				$ 166,000
Goodwill not deductible for tax purposes	$ 0

Concentrations of Significant48

Concentrations of Significant Customers and Credit Risk - Additional Information (Details) - Customer One and Customer Two - Sales Revenue, Net - Customer concentration risk	12 Months Ended
	Dec. 31, 2017
Minimum
Concentration Risk [Line Items]
Concentration risk, percentage	10.00%
Maximum
Concentration Risk [Line Items]
Concentration risk, percentage	15.00%

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Jul. 31, 2016	Jun. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Accounts receivable, net of allowances			$ 21,310	$ 18,109
Repayment of Notes Receivable from Related Parties			0	36,380	$ 0
Cash paid for taxes			$ 8,505	7,809	$ 11,723
Payments of preferred dividends	$ 18,900
Payments of common stock dividends	900
Subsidiary of common parent | QVC
Related Party Transaction [Line Items]
Accounts receivable, net of allowances				$ 784
Subsidiary of common parent | QVC | Total revenue | Customer concentration risk
Related Party Transaction [Line Items]
Concentration risk, percentage				7.00%	8.00%
Parent | Liberty
Related Party Transaction [Line Items]
Repayment of Notes Receivable from Related Parties		$ 36,400
Interest paid		2,400
Taxes amounts due for tax benefits	8,500
Cash paid for taxes	1,300
Proceeds from contributed capital	$ 6,000
Due to related parties				$ 33
Parent | Liberty | LIBOR
Related Party Transaction [Line Items]
Loans receivable, basis spread on variable rate				1.00%
Parent | Liberty
Related Party Transaction [Line Items]
Interest income, related party				$ 273	$ 600
Loan receivable, related party		$ 28,700

Capitalized Software - Summary

Capitalized Software - Summary of Capitalized Software Costs (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Research and Development [Abstract]
Capitalized software	$ 31,650	$ 32,506
Less accumulated amortization	(28,800)	(25,790)
Capitalized software, net	$ 2,850	$ 6,716

Capitalized Software - Narrativ

Capitalized Software - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Research and Development [Abstract]
Capitalized software impairment	$ 254
Capitalized software amortization expense	$ 4,900	$ 5,000	$ 3,400

Capitalized Software - Future A

Capitalized Software - Future Amortization (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Capitalized software, net	$ 2,850	$ 6,716
Capitalized software
Finite-Lived Intangible Assets [Line Items]
2,018	2,288
2,019	477
2,020	85
Capitalized software, net	$ 2,850

Goodwill and Intangible Asset53

Goodwill and Intangible Assets - Goodwill (Details)	12 Months Ended
	Dec. 31, 2017USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill change in carrying amount	$ 0

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 18,226	$ 18,958
Less accumulated depreciation	(12,160)	(11,329)
Property and equipment, net	6,066	7,629
Depreciation of property and equipment	3,200	3,000	$ 2,600
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	14,068	14,892
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,130	1,101
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 3,028	$ 2,965

Goodwill and Intangible Asset55

Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 3,500,000
Accumulated Amortization	(3,500,000)
Net Book Value	0
Amortization expense related to intangible assets	$ 0	$ 1,800,000	$ 1,800,000
Developed technology
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (Years)	2 years
Gross Carrying Amount	$ 1,500,000
Accumulated Amortization	(1,500,000)
Net Book Value	$ 0
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (Years)	2 years
Gross Carrying Amount	$ 2,000,000
Accumulated Amortization	(2,000,000)
Net Book Value	$ 0

Share-Based Awards - Narrative

Share-Based Awards - Narrative (Details)	Jan. 01, 2017shares	Jul. 22, 2016USD ($)shares	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2015USD ($)shares	Dec. 31, 2010shares	Dec. 31, 1999shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			4 years
Tax benefits recognized			$ 3,600,000	$ 87,200,000	$ 7,500,000
Cash received from exercise of stock options			$ 3,289,000	846,000	33,000
Expiration period			10 years
Spinoff transaction, exchange ratio		2.18
Adjustments to additional paid in capital, share-based compensation, restructuring event		$ 12,500,000
Cash received from employee stock purchase plan			$ 464,000	$ 0	0
Issuance of restricted stock units			0
Options and SARs | Common Series C
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options to purchase shares | shares		5,811,150
1999 Plan | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period							4 years
Number of shares authorized (in shares) | shares							4,000,000
Expiration period							10 years
Options outstanding (in shares) | shares		33,950
SAR Plan | SARs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period						4 years
Expiration period						10 years
Awards outstanding (in shares) | shares		2,629,666				6,000,000
1999 Plan and SAR Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected to vest, Aggregate intrinsic value		$ 86,700,000			$ 7,500,000
1999 Plan and SAR Plan | Options and SARs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding (in shares) | shares		2,663,616
Omnibus Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares) | shares	15,346,064
Number of additional shares authorized (in shares) | shares	2,146,064
Number of shares authorized as a percent of outstanding shares of common stock	5.00%
Expected to vest, Aggregate intrinsic value			23,000
Compensation not yet recognized			$ 1,400,000
Compensation cost not yet recognized, period for recognition			3 years 2 months
Omnibus Plan | Common Series C
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding (in shares) | shares			325,092	193,998
Expected to vest, Aggregate intrinsic value			$ 1,325,000
Options exercisable, weighted average exercise price (in dollars per share) | $ / shares			$ 14.55
Options outstanding, weighted average remaining contractual life			9 years
Options exercisable (in shares) | shares			28,274
Options exercisable, weighted average remaining contractual life			7 years 8 months
Omnibus Plan | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options to purchase shares | shares			543,495	505,831
Weighted average grant date fair value (in USD per share) | $ / shares			$ 16.15	$ 14.35
Vested (in shares) | shares			123,645
Omnibus Plan | RSUs | Common Series C
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost not yet recognized, period for recognition			2 years 9 months 23 days
Weighted average grant date fair value (in USD per share) | $ / shares				$ 14.35
Vested in the period fair value			$ 2,300,000
Vested (in shares) | shares				0	0
Compensation not yet recognized, options			4,284,144		$ 0
Legacy Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected to vest, Aggregate intrinsic value			1,700,000	$ 500,000
Compensation not yet recognized			$ 9,900,000
Compensation cost not yet recognized, period for recognition			2 years 7 months 7 days
Legacy Plans | Common Series C
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding (in shares) | shares			4,920,221	5,580,109
Expected to vest, Aggregate intrinsic value			$ 36,999,000
Options exercisable, weighted average exercise price (in dollars per share) | $ / shares			$ 9.61
Options outstanding, weighted average remaining contractual life			7 years 2 months
Options exercisable (in shares) | shares			2,457,076
Options exercisable, weighted average remaining contractual life			5 years 11 months
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares) | shares	1,329,212	900,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized, Annual Increase In Authorized Shares As A Percent Of Common Shares Outstanding Immediate Prior Day			1.00%
Employee stock purchase plan, purchase price, percentage of stock value		85.00%
Share based compensation costs associated with ESPP			$ 302,000
Shares issued under the ESPP (in shares) | shares			36,298
Cash received from employee stock purchase plan			$ 464,000
Transitional Stock Adjustment Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation not yet recognized, options			$ 0
Options exercisable, weighted average exercise price (in dollars per share) | $ / shares			$ 12.49
Transitional Stock Adjustment Plan | Common Series C
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding (in shares) | shares			866,265	1,006,043
Expected to vest, Aggregate intrinsic value			$ 6,159,000
Options vested and expected to vest, aggregate intrinsic value			$ 1,500,000	$ 200,000
Options exercisable, weighted average exercise price (in dollars per share) | $ / shares			$ 7.23
Options outstanding, weighted average remaining contractual life			3 years 6 months
Options exercisable (in shares) | shares			460,899
Options exercisable, weighted average remaining contractual life			2 years 7 months
Transitional Stock Adjustment Plan | Series A Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options vested and expected to vest, aggregate intrinsic value			$ 700,000	$ 100,000
Transitional Stock Adjustment Plan | Common Series A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding (in shares) | shares			266,155	329,188
Expected to vest, Aggregate intrinsic value			$ 3,149,000
Options exercisable, weighted average exercise price (in dollars per share) | $ / shares			$ 6.44
Options outstanding, weighted average remaining contractual life			3 years
Options exercisable (in shares) | shares			203,611
Options exercisable, weighted average remaining contractual life			2 years 4 months
Transitional Stock Adjustment Plan | Common Series B
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding (in shares) | shares			172,882
Expected to vest, Aggregate intrinsic value			$ 353,000
Compensation not yet recognized, options			0
Options vested and expected to vest, aggregate intrinsic value			$ 2,000,000
Options exercisable, weighted average exercise price (in dollars per share) | $ / shares			$ 11.89
Options outstanding, weighted average remaining contractual life			4 years 2 months
Options exercisable (in shares) | shares			32,052
Options exercisable, weighted average remaining contractual life			4 years 11 months
Transitional Stock Adjustment Plan | RSUs | Common Series C
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of restricted stock units			$ 236
Transitional Stock Adjustment Plan | RSUs | Common Series A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of restricted stock units			118
Transitional Stock Adjustment Plan | Restricted Stock Awards (RSAs) | Common Series C
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of restricted stock units			8,745
Transitional Stock Adjustment Plan | Restricted Stock Awards (RSAs) | Common Series A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of restricted stock units			$ 4,357
Original Ventures RSUs | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award conversion ratio		0.1
Original Ventures RSUs | RSUs | Common Series C
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award conversion ratio		0.2
Original Ventures RSAs | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award conversion ratio		0.1
Original Ventures RSAs | RSUs | Common Series C
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award conversion ratio		0.2

Share-Based Awards - Schedule o

Share-Based Awards - Schedule of Share-based Compensation Allocation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	$ 8,629	$ 11,290	$ 42,150
Cost of revenue
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	396	(102)	2,361
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	1,728	2,261	7,229
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	553	834	4,098
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	$ 5,952	$ 8,297	$ 28,462

Share-Based Awards - Stock Opti

Share-Based Awards - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
2016 Omnibus Incentive Plan
Weighted average exercise price
Expected to vest, Aggregate intrinsic value	$ 23
2016 Omnibus Incentive Plan | Common Series C
Number of Options
Outstanding, beginning balance (in shares)	193,998
Granted (in shares)	364,075
Exercised (in shares)	(3,544)
Forfeited (in shares)	(229,437)
Outstanding, ending balance (in shares)	325,092	193,998
Exercisable (in shares)	28,274
Expected to vest (in shares)	285,180
Weighted average exercise price
Outstanding, beginning balance (in dollars per share)	$ 14.59
Granted (in dollars per share)	16.56
Exercised (in dollars per share)	14.85
Forfeited (in dollars per share)	15.68
Outstanding, ending balance (in dollars per share)	$ 16.02	$ 14.59
Outstanding, Weighted average remaining contractual life	9 years
Options outstanding, aggregate intrinsic value	$ 1,502
Exercisable, Weighted average exercise price (in dollars per share)	$ 14.55
Exercisable, Weighted average remaining contractual life	7 years 8 months
Stock options, exercisable, intrinsic value	$ 171
Vested and expected to vest, weighted average exercise price (in dollars per share)	$ 15.99
Expected to vest, Weighted average remaining contractual life	9 years 8 days
Expected to vest, Aggregate intrinsic value	$ 1,325
Legacy Plans
Weighted average exercise price
Expected to vest, Aggregate intrinsic value	$ 1,700	$ 500
Legacy Plans | Common Series C
Number of Options
Outstanding, beginning balance (in shares)	5,580,109
Granted (in shares)	0
Exercised (in shares)	(205,963)
Forfeited (in shares)	(453,925)
Outstanding, ending balance (in shares)	4,920,221	5,580,109
Exercisable (in shares)	2,457,076
Expected to vest (in shares)	4,643,090
Weighted average exercise price
Outstanding, ending balance (in dollars per share)	$ 12.83
Outstanding, Weighted average remaining contractual life	7 years 2 months
Options outstanding, aggregate intrinsic value	$ 38,187
Exercisable, Weighted average exercise price (in dollars per share)	$ 9.61
Exercisable, Weighted average remaining contractual life	5 years 11 months
Stock options, exercisable, intrinsic value	$ 26,978
Vested and expected to vest, weighted average exercise price (in dollars per share)	$ 12.62
Expected to vest, Weighted average remaining contractual life	7 years 26 days
Expected to vest, Aggregate intrinsic value	$ 36,999
Transitional Stock Adjustment Plan
Weighted average exercise price
Exercisable, Weighted average exercise price (in dollars per share)	$ 12.49
Transitional Stock Adjustment Plan | Common Series C
Number of Options
Outstanding, beginning balance (in shares)	1,006,043
Granted (in shares)	0
Exercised (in shares)	(136,220)
Forfeited (in shares)	(3,558)
Outstanding, ending balance (in shares)	866,265	1,006,043
Exercisable (in shares)	460,899
Weighted average exercise price
Outstanding, ending balance (in dollars per share)	$ 9.45
Outstanding, Weighted average remaining contractual life	3 years 6 months
Options outstanding, aggregate intrinsic value	$ 9,650
Exercisable, Weighted average exercise price (in dollars per share)	$ 7.23
Exercisable, Weighted average remaining contractual life	2 years 7 months
Expected to vest, Aggregate intrinsic value	$ 6,159
Transitional Stock Adjustment Plan | Common Series A
Number of Options
Outstanding, beginning balance (in shares)	329,188
Granted (in shares)	0
Exercised (in shares)	(61,248)
Forfeited (in shares)	(1,785)
Outstanding, ending balance (in shares)	266,155	329,188
Exercisable (in shares)	203,611
Weighted average exercise price
Outstanding, beginning balance (in dollars per share)	$ 7.46
Granted (in dollars per share)	0
Exercised (in dollars per share)	5.63
Forfeited (in dollars per share)	12.51
Outstanding, ending balance (in dollars per share)	$ 7.90	$ 7.46
Outstanding, Weighted average remaining contractual life	3 years
Options outstanding, aggregate intrinsic value	$ 3,733
Exercisable, Weighted average exercise price (in dollars per share)	$ 6.44
Exercisable, Weighted average remaining contractual life	2 years 4 months
Expected to vest, Aggregate intrinsic value	$ 3,149
Granted [Member] | Legacy Plans | Common Series C
Weighted average exercise price
Outstanding, beginning balance (in dollars per share)	$ 12.96
Outstanding, ending balance (in dollars per share)		12.96
Granted [Member] | Transitional Stock Adjustment Plan | Common Series C
Weighted average exercise price
Outstanding, beginning balance (in dollars per share)	8.93
Outstanding, ending balance (in dollars per share)		$ 8.93
Exercised [Member] | Legacy Plans | Common Series C
Weighted average exercise price
Granted (in dollars per share)	0
Exercised (in dollars per share)	10.38
Exercised [Member] | Transitional Stock Adjustment Plan | Common Series C
Weighted average exercise price
Granted (in dollars per share)	0
Exercised (in dollars per share)	5.62
Forfeited [Member] | Legacy Plans | Common Series C
Weighted average exercise price
Forfeited (in dollars per share)	15.53
Forfeited [Member] | Transitional Stock Adjustment Plan | Common Series C
Weighted average exercise price
Forfeited (in dollars per share)	$ 12.46

Share-Based Awards - Restricted

Share-Based Awards - Restricted Stock Unit Activity (Details) - Omnibus Plan	12 Months Ended
	Dec. 31, 2017$ / sharesshares
RSUs
Number of awards
Outstanding, beginning balance (in shares)	505,831
Granted (in shares)	442,263
Vested (in shares)	(123,645)
Forfeited (in shares)	(280,954)
Outstanding, ending balance (in shares)	543,495
Weighted average grant-date fair value
Outstanding, beginning balance (in dollars per share) | $ / shares	$ 14.35
Granted (in dollars per share) | $ / shares	17.31
Vested (in dollars per share) | $ / shares	14.34
Forfeited (in dollars per share) | $ / shares	15.36
Outstanding, ending balance (in dollars per share) | $ / shares	$ 16.15
DSUs
Number of awards
Outstanding, ending balance (in shares)	40,850

Income Taxes - Components of Ta

Income Taxes - Components of Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current
Federal	$ 10,884	$ (11,497)	$ 7,931
State and local	1,411	(2,674)	2,477
Foreign	10	7	0
Total current	12,305	(14,164)	10,408
Deferred
Federal	2,815	15,869	(9,942)
State and local	756	5,457	(2,347)
Total deferred	3,571	21,326	(12,289)
Total tax expense (benefit)	$ 15,876	$ 7,162	$ (1,881)

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Accrued interest and penalties recognized	$ 0	$ 0	$ 0
Statutory rate		35.00%	35.00%	35.00%
Income (loss) before income taxes		$ 25,734,000	$ 16,258,000	$ (6,348,000)
Impact of the Tax Act on deferred tax assets		3,161,000	0	0
Section 162(m) adjustment		3,276,000	0	0
Income tax expense (benefit)		15,876,000	7,162,000	(1,881,000)
Reduction to deferred tax asset for share-based awards			(31,300,000)
Deferred income tax expense (benefit)		3,571,000	21,326,000	$ (12,289,000)
Restatement Adjustment | Correction for application of NY tax law change
Operating Loss Carryforwards [Line Items]
Income tax expense (benefit)	$ 1,500,000
Internal Revenue Service (IRS) | Domestic tax authority
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards generated during the period			74,700,000
Internal Revenue Service (IRS) | Domestic tax authority | Prior Two Tax Years
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards generated during the period			49,100,000
Internal Revenue Service (IRS) | Domestic tax authority | Tax Year 2016
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards generated during the period			$ 25,600,000
Equity Distribution		5,100,000
Internal Revenue Service (IRS) | Domestic tax authority | Future Tax Years
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards generated during the period		7,900,000
Internal Revenue Service (IRS) | Domestic tax authority | Tax Years 2017 To 2019
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards generated during the period		1,500,000
Internal Revenue Service (IRS) | Domestic tax authority | Tax Years 2020 To 2033
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards generated during the period		$ 350,000

Income Taxes - Effective Tax Ra

Income Taxes - Effective Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Computed expected tax expense	$ 9,007	$ 5,690	$ (2,222)
Increase (decrease) resulting from:
Impact of the Tax Act on deferred tax assets	3,161	0	0
Section 162(m) adjustment	3,276	0	0
State tax law change	0	1,524	0
State and local income taxes, net of federal income tax benefit	852	284	(21)
Impact of state rate change on deferred taxes	293	0	105
Non-deductible expenses	21	66	228
Excess share-based compensation deduction	(157)	0	0
Market adjustment for options exercised	0	127	319
Write-off federal NOL	0	122	0
Research and development tax credits	(559)	(649)	(368)
Other	(18)	(2)	78
Total tax expense (benefit)	$ 15,876	$ 7,162	$ (1,881)

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Accounts receivable allowances	$ 268	$ 75
Deferred revenue	1,695	2,721
Accrued liabilities	965	426
Shared-based compensation	3,106	5,948
Net operating loss	1,852	3,999
Other	59	1
Total deferred tax assets	7,945	13,170
Deferred tax liabilities:
Software and deferred costs	1,909	4,372
Property and equipment	238	1,084
Total gross deferred tax liabilities	2,147	5,456
Net deferred tax asset	$ 5,798	$ 7,714

Long-Term Debt (Details)

Long-Term Debt (Details) - Revolving Credit Facility - Credit Agreement, June 2016 - USD ($)	Jun. 28, 2016	Dec. 31, 2017
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 125,000,000
Borrowings outstanding		$ 0
Letters of credit outstanding		0
Available borrowings under facility		$ 125,000,000
Other long-term assets
Debt Instrument [Line Items]
Debt issuance charges	$ 1,100,000
Minimum
Debt Instrument [Line Items]
Commitment fee percentage on unused portion	0.25%
Maximum
Debt Instrument [Line Items]
Commitment fee percentage on unused portion	0.50%
Base Rate | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	0.75%
Base Rate | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	1.25%
Eurodollar | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	1.75%
Eurodollar | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	2.25%

Commitments and Contingencies65

Commitments and Contingencies (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Total rent expense	$ 2,000,000	$ 1,900,000	$ 1,400,000
Deferred rent	2,500,000	$ 1,135,482
2,018	2,652,000
2,019	2,201,000
2,020	2,183,000
2,021	2,139,000
2,022	362,000
Total minimum lease payments	9,537,000
Operating leases, rental income from sub-tenants	2,400,000
Future minimum payments due from sub-tenants December 31, 2018 through 2021	$ 600,000

Restructuring - Narrative (Deta

Restructuring - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Expected restructuring costs	$ 6,000
Restructuring charges incurred	2,279
Restructuring reserve	1,276	$ 0
Accounts Payable and Accrued Liabilities
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	500
Other Noncurrent Liabilities
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	$ 800

Restructuring - Schedule of Res

Restructuring - Schedule of Restructuring Charges (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses	$ 2,279
Cost of revenue
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses	486
Research and development
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses	1,345
Sales and marketing
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses	384
General and administrative
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses	64
Termination & retention benefits
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses	2,088
Termination & retention benefits | Cost of revenue
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses	295
Termination & retention benefits | Research and development
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses	1,345
Termination & retention benefits | Sales and marketing
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses	384
Termination & retention benefits | General and administrative
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses	64
Impairment of capitalized software
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses	191
Impairment of capitalized software | Cost of revenue
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses	191
Impairment of capitalized software | Research and development
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses	0
Impairment of capitalized software | Sales and marketing
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses	0
Impairment of capitalized software | General and administrative
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses	$ 0

Restructuring - Schedule of R68

Restructuring - Schedule of Restructuring Liability (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Restructuring Reserve [Roll Forward]
Balance at January 1, 2017	$ 0
Restructuring charges	2,088
Non-cash adjustments	0
Cash payouts	(812)
Balance at December 31, 2017	$ 1,276

Selected Quarterly Informatio69

Selected Quarterly Information (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 36,731	$ 24,614	$ 25,208	$ 24,568	$ 32,881	$ 22,478	$ 23,103	$ 22,090	$ 111,121	$ 100,552	$ 87,614
Gross profit	31,314	19,586	19,569	19,052	26,986	16,741	17,783	15,985	89,521	77,495	64,914
Income from operations	15,040	3,318	3,841	4,267	11,805	633	7,280	(3,026)	26,466	16,692	(6,948)
Net income	$ 3,166	$ 1,988	$ 2,245	$ 2,459	$ 5,952	$ 710	$ 4,424	$ (1,990)	$ 9,858	$ 9,096	$ (4,467)
Earnings per share:
Basic (in dollars per share)	$ 0.07	$ 0.05	$ 0.05	$ 0.06	$ 0.14	$ 0.02	$ 0.10	$ (0.04)	$ 0.23	$ 0.21	$ (0.10)
Diluted (in dollars per share)	$ 0.07	$ 0.04	$ 0.05	$ 0.06	$ 0.13	$ 0.02	$ 0.10	$ (0.04)	$ 0.22	$ 0.21	$ (0.10)