2U (TWOUQ) 10-K 26 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 24, 2015	Jun. 30, 2014
Document and Entity Information
Entity Registrant Name	2U, Inc.
Entity Central Index Key	1459417
Document Type	10-K
Document Period End Date	31-Dec-14
Amendment Flag	FALSE
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Public Float			$451,962,721
Entity Common Stock, Shares Outstanding		41,018,404
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$86,929	$7,012
Accounts receivable, net	350	1,835
Advance to clients, current		581
Prepaid expenses	2,709	1,763
Total current assets	89,988	11,191
Property and equipment, net	6,755	5,231
Capitalized content development costs, net	13,155	8,904
Advance to clients, non-current	1,675
Other non-current assets	1,466	3,326
Total assets	113,039	28,652
Current liabilities:
Accounts payable	2,293	5,089
Accrued expenses and other current liabilities	17,138	12,025
Deferred revenue	1,906	1,266
Refunds payable	2,431	1,831
Total current liabilities	23,768	20,211
Rebate reserve	639	1,571
Other non-current liabilities	621	847
Total liabilities	25,028	22,629
Commitments and contingencies (Note 5)
Redeemable convertible preferred stock:
Redeemable convertible preferred stock		98,047
Stockholders' equity (deficit):
Common stock, $0.001 par value, 200,000,000 shares authorized, 40,735,069 shares issued and outstanding as of December 31, 2014; 60,000,000 shares authorized, 7,629,133 shares issued and outstanding as of December 31, 2013	41	8
Additional paid-in capital	216,818	7,817
Accumulated deficit	-128,848	-99,849
Total stockholders' equity (deficit)	88,011	-92,024
Total liabilities, redeemable convertible preferred stock and stockholders' equity (deficit)	113,039	28,652
Series A
Redeemable convertible preferred stock:
Redeemable convertible preferred stock		12,384
Series B
Redeemable convertible preferred stock:
Redeemable convertible preferred stock		22,210
Series C
Redeemable convertible preferred stock:
Redeemable convertible preferred stock		32,405
Series D
Redeemable convertible preferred stock:
Redeemable convertible preferred stock		$31,048

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Redeemable convertible preferred stock, shares authorized	0	0
Redeemable convertible preferred stock, shares issued	0	0
Redeemable convertible preferred stock, shares outstanding	0	0
Preferred stock, par value (in dollars per share)	$0.00	$0.00
Preferred stock, shares authorized	5,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, shares authorized	200,000,000	60,000,000
Common stock, shares issued	40,735,069	7,629,133
Common stock, shares outstanding	40,735,069	7,629,133
Series A
Redeemable convertible preferred stock, par value (in dollars per share)	$0.00	$0.00
Redeemable convertible preferred stock, shares authorized	0	10,033,976
Redeemable convertible preferred stock, shares issued	0	10,033,976
Redeemable convertible preferred stock, shares outstanding	0	10,033,976
Series B
Redeemable convertible preferred stock, par value (in dollars per share)	$0.00	$0.00
Redeemable convertible preferred stock, shares authorized	0	5,057,901
Redeemable convertible preferred stock, shares issued	0	5,057,901
Redeemable convertible preferred stock, shares outstanding	0	5,057,901
Series C
Redeemable convertible preferred stock, par value (in dollars per share)	$0.00	$0.00
Redeemable convertible preferred stock, shares authorized	0	4,429,601
Redeemable convertible preferred stock, shares issued	0	4,429,601
Redeemable convertible preferred stock, shares outstanding	0	4,429,601
Series D
Redeemable convertible preferred stock, par value (in dollars per share)	$0.00	$0.00
Redeemable convertible preferred stock, shares authorized	0	4,069,352
Redeemable convertible preferred stock, shares issued	0	3,979,730
Redeemable convertible preferred stock, shares outstanding	0	3,979,730

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Consolidated Statements of Operations
Revenue	$30,756	$28,407	$24,744	$26,332	$24,803	$20,499	$18,691	$19,134	$110,239	$83,127	$55,879
Costs and expenses:
Servicing and support	7,012	6,598	7,000	6,248	6,202	5,842	5,656	5,018	26,858	22,718	14,926
Technology and content development	5,403	5,726	5,818	5,674	6,528	5,113	4,596	3,235	22,621	19,472	8,299
Program marketing and sales	16,296	16,971	16,710	15,241	13,226	15,412	13,695	11,770	65,218	54,103	45,390
General and administrative	5,973	6,303	5,708	5,436	4,046	4,269	3,654	2,871	23,420	14,840	10,342
Total costs and expenses	34,684	35,598	35,236	32,599	30,002	30,636	27,601	22,894	138,117	111,133	78,957
Loss from operations	-3,928	-7,191	-10,492	-6,267	-5,199	-10,137	-8,910	-3,760	-27,878	-28,006	-23,078
Other income (expense):
Interest expense	-119	-176	-134	-784	15	-1	5	8	-1,213	27	-73
Interest income	30	30	31	1	5	5	10	6	92	26	38
Total other income (expense)	-89	-146	-103	-783	20	4	15	14	-1,121	53	-35
Loss before income taxes									-28,999	-27,953	-23,113
Net loss	-4,017	-7,337	-10,595	-7,050	-5,179	-10,133	-8,895	-3,746	-28,999	-27,953	-23,113
Preferred stock accretion									-89	-347	-339
Net loss attributable to common stockholders									($29,088)	($28,300)	($23,452)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	($0.10)	($0.18)	($0.27)	($0.92)	($0.69)	($1.37)	($1.20)	($0.51)	($0.91)	($3.81)	($3.33)
Weighted average common shares outstanding, basic and diluted (in shares)	40,577,087	40,269,937	39,304,884	7,698,709	7,528,940	7,415,777	7,398,059	7,386,133	32,075,107	7,432,055	7,037,090

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Stockholders' Equity (Deficit) (USD $)	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Total
In Thousands, except Share data, unless otherwise specified
Balance at Dec. 31, 2011	$6	$3,817	($48,673)	($44,850)
Balance (in shares) at Dec. 31, 2011	6,680,085
Increase (Decrease) in Stockholders' Equity
Exercise of stock options	1	610		611
Exercise of stock options (in shares)	706,048
Accretion of issuance costs on redeemable convertible preferred stock		-339		-339
Stock-based compensation expense		1,395		1,395
Net loss			-23,113	-23,113
Balance at Dec. 31, 2012	7	5,483	-71,786	-66,296
Balance (in shares) at Dec. 31, 2012	7,386,133
Increase (Decrease) in Stockholders' Equity
Exercise of stock options	1	324		325
Exercise of stock options (in shares)	290,604
Repurchase of common shares		-69	-110	-179
Repurchase of common shares (in shares)	-47,604
Accretion of issuance costs on redeemable convertible preferred stock		-347		-347
Stock-based compensation expense		2,426		2,426
Net loss			-27,953	-27,953
Balance at Dec. 31, 2013	8	7,817	-99,849	-92,024
Balance (in shares) at Dec. 31, 2013	7,629,133			7,629,133
Increase (Decrease) in Stockholders' Equity
Exercise of stock options	1	2,281		2,282
Exercise of stock options (in shares)	940,642
Grant of common stock		55		55
Grant of common stock (in shares)	5,000
Accretion of issuance costs on redeemable convertible preferred stock		-89		-89
Stock-based compensation expense		7,527		7,527
Conversion of redeemable convertible preferred stock to common stock	23	98,113		98,136
Conversion of redeemable convertible preferred stock to common stock (in shares)	23,501,208
Conversion of Series D warrants to common stock warrants		821		821
Issuance of common stock from initial public offering, net of issuance costs	9	100,293		100,302
Issuance of common stock from initial public offering, net of issuance costs (in shares)	8,626,377
Exercise of warrants to purchase common stock (in shares)	32,709
Net loss			-28,999	-28,999
Balance at Dec. 31, 2014	$41	$216,818	($128,848)	$88,011
Balance (in shares) at Dec. 31, 2014	40,735,069			40,735,069

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities
Net loss	($28,999)	($27,953)	($23,113)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	5,572	4,335	2,869
Stock-based compensation expense	7,527	2,426	1,395
Amortization of deferred financing costs			74
Change in the fair value of the Series D redeemable convertible preferred stock warrants prior to conversion	695	-33	-22
Loss on impairment and disposal of long-lived assets		811
Changes in operating assets and liabilities:
Accounts receivable, net	1,485	-1,587	1,142
Advances to clients	-1,094	415
Prepaid expenses	-946	-939	-24
Related party receivable		265	-265
Other assets	779	-1,384	-133
Accounts payable	-2,565	1,894	1,328
Accrued expenses and other current liabilities	5,597	4,986	1,047
Deferred revenue	640	530	-5,002
Refunds payable	600	603	159
Rebate reserve	-932	-320	240
Other liabilities	-44	269	120
Net cash used in operating activities	-11,685	-15,682	-20,185
Cash flows from investing activities
Expenditures for property and equipment	-3,803	-2,367	-2,275
Capitalized content development cost expenditures	-7,150	-5,213	-2,578
Other investing activities	-29	-56	-362
Net cash used in investing activities	-10,982	-7,636	-5,215
Cash flows from financing activities
Proceeds from issuance of common stock, net of offering costs	100,302
Proceeds from exercise of stock options	2,282	325	611
Proceeds from revolving line of credit	5,000
Payment on revolving line of credit	-5,000
Repurchase of common shares		-179
Proceeds from issuance of Series D redeemable convertible preferred stock, net of issuance costs		4,994	26,021
Net cash provided by financing activities	102,584	5,140	26,632
Net increase (decrease) in cash and cash equivalents	79,917	-18,178	1,232
Cash and cash equivalents, beginning of period	7,012	25,190	23,958
Cash and cash equivalents, end of period	86,929	7,012	25,190
Supplemental disclosure of non-cash investing and financing activities
Accretion of issuance costs on redeemable convertible preferred stock	89	347	339
Accrued capital expenditures	557	216	40
Deferred offering costs included in accounts payable and accrued expenses		1,057
Issuance of Series D redeemable convertible preferred stock warrant in connection with revolving line of credit		107
Common stock granted in exchange for consulting services received	$55

Description_of_the_Business

Description of the Business	12 Months Ended
	Dec. 31, 2014
Description of the Business
Description of the Business	1. Description of the Business
	2U, Inc. (the "Company") was incorporated as 2Tor Inc. in the State of Delaware in April 2008 and changed its name to 2U, Inc. on October 11, 2012. Under long-term agreements, the Company provides an integrated solution comprised of cloud-based software-as-a-service ("SaaS"), fused with technology-enabled services (together, the "Platform"), that allows leading colleges and universities to deliver high quality online degree programs, extending the universities' reach and distinguishing their brands. The Company's SaaS technology consists of (i) a comprehensive learning environment ("Online Campus"), which acts as the hub for all student and faculty academic and social interaction, and (ii) operations applications, which provide the content management, admissions application processing, customer relationship management, and other functionality necessary to effectively operate the Company's clients' programs. The Company also provides a suite of technology-enabled services that support the complete lifecycle of a higher education program, including attracting students, advising prospective students through the admissions application process, providing technical, success coaching and other support, facilitating accessibility to individuals with disabilities, and facilitating in-program field placements.
	On April 2, 2014, the Company closed the initial public offering of its common stock ("IPO") in which the Company issued and sold 8,626,377 shares of its common stock, including the partial exercise of the underwriters' over-allotment option, at an issuance price of $13.00 per share. The Company received net proceeds of $100.3 million after deducting underwriting discounts and commissions of $7.8 million and other offering expenses of approximately $4.0 million. Upon the closing of the IPO, all shares of the then-outstanding redeemable convertible preferred stock automatically converted into an aggregate of 23,501,208 shares of common stock, based on the shares of redeemable convertible preferred stock outstanding as of April 2, 2014. In addition, the outstanding Series D warrants automatically converted into warrants to purchase common stock, and the preferred stock warrant liability of $0.8 million as of April 2, 2014 was reclassified to additional paid-in capital.

Significant_Accounting_Policie

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Significant Accounting Policies
Significant Accounting Policies	2. Significant Accounting Policies
	Principles of Consolidation
	The accompanying consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary and have been prepared in accordance with United States generally accepted accounting principles ("U.S. GAAP"). All intercompany accounts and transactions have been eliminated in consolidation.
	Use of Estimates
	The preparation of financial statements in accordance with U.S. GAAP requires management to make certain estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. On an ongoing basis, the Company evaluates its estimates, including those related to the useful lives of long-lived assets, fair value measurement and income taxes, among others. The Company bases its estimates on historical experience and on various other assumptions that it believes to be reasonable, the results of which form the basis for making judgments about the carrying value of assets and liabilities. Actual results could differ from those estimates.
	Cash and Cash Equivalents
	Cash and cash equivalents consist of bank checking and money market accounts and investments in certificates of deposit that mature in less than three months. The Company considers all highly liquid marketable securities with maturities at the time of purchase of three months or less to be cash equivalents, and they are carried at fair value.
	Revenue Recognition and Deferred Revenue
	The Company recognizes revenue when all of the following conditions are met: (i) persuasive evidence of an arrangement exists, (ii) rendering of services is complete, (iii) fees are fixed or determinable and (iv) collection of fees is reasonably assured.
	The Company primarily derives its revenue from long-term contracts that typically range from 10 to 15 years in length. Under these contracts, the Company enables access to its Platform to its clients and their faculty and students. The Company is entitled to a contractually specified percentage of net program proceeds from its clients. These net program proceeds represent gross proceeds billed by clients to students, less credit card fees and other specified charges the Company has agreed to exclude in certain of its client contracts. A refund allowance is established for the Company's share of tuition and fees ultimately uncollected by its clients. The Company also offered rebates to a group of students who enrolled in a specific client program between 2009 and 2011, which the Company will pay to the student if he or she completes the degree and certain post-graduation work requirements within a specified period of time. These rebates and refunds offset the net program proceeds recognized as revenue. Revenue is recognized ratably over the service period, which the Company defines as the first through the last day of classes for each semester in a client's program. The Company invoices its clients based on enrollment reports that are generated by its clients. In some instances, these enrollment reports are received prior to the conclusion of the drop/add period. In such cases, the Company establishes a reserve against revenue, if necessary, based on its estimate of changes in enrollments expected prior to the end of the drop/add period.
	The Company generates substantially all of its revenue from multiple-deliverable contractual arrangements with its clients. Under each of these arrangements, the Company provides (i) access to Online Campus, which serves as a learning platform for its client's faculty and students and which also enables a comprehensive range of other client functions, (ii) access to operations applications which provide the content management, admissions application processing, customer relationship management, and other functionality necessary to effectively operate the Company's clients' programs and (iii) technology-enabled services that support the complete lifecycle of a higher education program, including attracting students, advising prospective students through the admissions application process, providing technical, success coaching and other support, facilitating accessibility to individuals with disabilities, and facilitating in-program field placements.
	In order to treat deliverables in a multiple-deliverable contractual arrangement as separate units of accounting, deliverables must have standalone value upon delivery. The technology-enabled services within the Platform are provided primarily in support of programs delivered through Online Campus, and for students of the programs delivered through Online Campus. Accordingly, the Company has determined that no individual deliverable has standalone value upon delivery and, therefore, deliverables within the Company's multiple-deliverable arrangements do not qualify for treatment as separate units of accounting. Accordingly, the Company considers all deliverables to be a single unit of accounting and recognizes revenue from the entire arrangement over the term of the service period.
	Advance payments are recorded as deferred revenue until services are delivered or obligations are met, at which time revenue is recognized. Deferred revenue as of a particular balance sheet date represents the excess of amounts received as compared to amounts recognized in revenue in the consolidated statements of operations as of the end of the reporting period, and such amounts are reflected as a current liability on the Company's consolidated balance sheets.
	Advertising Costs
	The Company expenses advertising costs as incurred. The amounts expensed for the years ended December 31, 2014, 2013 and 2012 were not material. The Company records its advertising costs as program marketing and sales expense in the Company's consolidated statements of operations.
	Fair Value Measurements
	The carrying amounts of certain assets and liabilities, including cash and cash equivalents, accounts receivable, accounts payable and accrued expenses and other current liabilities, approximate their respective fair values due to their short-term nature.
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date, based on the Company's principal or, in the absence of a principal, most advantageous, market for the specific asset or liability.
	U.S. GAAP provides for a three-tier fair value hierarchy to classify and disclose all assets and liabilities measured at fair value on a recurring basis, as well as assets and liabilities measured at fair value on a non-recurring basis, in periods subsequent to their initial measurement. The fair value hierarchy requires the Company to use observable inputs when available, and to minimize the use of unobservable inputs when determining fair value. The three tiers are defined as follows:
	•	Level 1—Observable inputs that reflect quoted market prices (unadjusted) for identical assets or liabilities in active markets;
	•	Level 2—Observable inputs, other than quoted prices in active markets, that are observable either directly or indirectly in the marketplace for identical or similar assets and liabilities; and
	•	Level 3—Unobservable inputs that are supported by little or no market data, which require the Company to develop its own assumptions about the assumptions market participants would use in pricing the asset or liability based on the best information available in the circumstances.
	Assets and Liabilities Measured at Fair Value on a Recurring Basis
	The Company evaluates its financial assets and liabilities subject to fair value measurements on a recurring basis to determine the appropriate level in which to classify them for each reporting period. This determination requires significant judgments to be made. The following tables summarize the conclusions reached as of December 31, 2014 and 2013:
			Balance as of December 31, 2014
			Total			Level 1			Level 2			Level 3
			(in thousands)
	Assets:
	Cash equivalents		$	82,939		$	82,939		$	—		$	—
	Liabilities:
	Series D redeemable convertible preferred stock warrants		$	—		$	—		$	—		$	—
			Balance as of December 31, 2013
			Total			Level 1			Level 2			Level 3
			(in thousands)
	Assets:
	Cash equivalents		$	3,357		$	3,357		$	—		$	—
	Liabilities:
	Series D redeemable convertible preferred stock warrants		$	126		$	—		$	—		$	126
	Prior to converting to common stock warrants upon the closing of the IPO on April 2, 2014, the Company used an option pricing model to determine the fair value of the Series D redeemable convertible preferred stock warrants. The valuation required the input of subjective assumptions, including the risk-free interest rate, the value of the underlying securities and the expected stock price volatility. The risk-free interest rate assumption was based upon observed interest rates for constant maturity U.S. Treasury securities consistent with the term of the warrants. The expected stock price volatility assumption was based on historical volatilities for publicly traded stock of comparable companies over the term of the warrants. The value of the underlying securities assumption was based upon the market price of the Company's common stock as the redeemable convertible preferred stock warrants became convertible into shares of common stock upon closing of the IPO.
	Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs
	The following table presents the changes in the Company's Level 3 instruments measured at fair value on a recurring basis:
			Series C			Series D
			Warrant			Warrants
			(in thousands)
	Balance as of December 31, 2012		$	—		$	52
	Issuance of warrant			—			107
	Change in fair value of warrant liability			—			(33	)
	Balance as of December 31, 2013			—			126
	Change in fair value of warrant liability			—			695
	Reclassification of warrant liability to additional paid-in capital						(821	)
	Balance as of December 31, 2014		$	—		$	—
	Accounts Receivable and Allowance for Doubtful Accounts
	Accounts receivable are stated at realizable value. The Company extends a minimal amount of uncollateralized credit to its clients. The Company utilizes the allowance method to provide for doubtful accounts based on management's evaluation of the collectability of the amounts due. The Company's estimate is based on historical collection experience and a review of the current status of accounts receivable. Historically, actual write-offs for uncollectible accounts have not significantly differed from the Company's estimates. As of December 31, 2014 and 2013, the Company determined that no significant allowances for doubtful accounts were necessary.
	Concentration of Credit Risk
	Financial instruments that subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents and accounts receivable. All of the Company's cash is held at financial institutions that management believes to be of high credit quality. The Company's bank accounts exceed federally insured limits at times. The Company has not experienced any losses on cash to date. To manage accounts receivable risk, the Company evaluates the creditworthiness of its clients and maintains an allowance for doubtful accounts, if needed.
	Three of the Company's clients accounted for the following percentages of revenue for the periods presented below:
			Year Ended
			December 31,
			2014			2013			2012
	Client A			55	%		69	%		78	%
	Client B			14			16			15
	Client C			13			12			7
	Additionally, the Company's largest client accounted for 35% and 51% of the Company's accounts receivable balance as of December 31, 2014 and 2013, respectively. Further, two additional clients accounted for more than 10% of the Company's accounts receivable balance as of December 31, 2014, while one additional client accounted for more than 10% of the Company's accounts receivable balance as of December 31, 2013.
	Property and Equipment
Property and equipment is stated at cost less accumulated depreciation and amortization. Computer software is included in property and equipment and consists of internally-developed software. Expenditures for major additions, construction and improvements are capitalized. Depreciation and amortization is expensed using the straight-line method over the estimated useful lives of the related assets, which range from three to five years for computer hardware and five to seven years for furniture and office equipment. Leasehold improvements are depreciated on a straight-line basis over the lesser of the remaining term of the leased facility or the estimated useful life of the improvement, which ranges from four to ten years. Useful lives of significant assets are periodically reviewed and adjusted prospectively to reflect the Company's current estimates of the respective assets' expected utility. Repair and maintenance costs are expensed as incurred.
The Company capitalizes certain costs associated with internally-developed software, primarily consisting of direct labor associated with creating the software. Software development projects generally include three stages: the preliminary project stage (all costs are expensed as incurred), the application development stage (certain costs are capitalized and certain costs are expensed as incurred) and the post-implementation/operation stage (all costs are expensed as incurred). Costs capitalized in the application development stage include costs of designing the application, coding, integrating the Company's and the university's networks and systems, and the testing of the software. Capitalization of costs requires judgment in determining when a project has reached the application development stage and the period over which the Company expects to benefit from the use of that software. Once the software is placed in service, these costs are depreciated on the straight-line method over the estimated useful life of the software, which is generally three years. Internal software development costs of $2.3 million, $1.3 million and $1.1 million were capitalized during the years ended December 31, 2014, 2013 and 2012, respectively. Amortization expense related to the capitalized internally-developed software was $1.4 million, $1.5 million and $0.9 million for the years ended December 31, 2014, 2013 and 2012, respectively, and is included in technology and content development costs in the accompanying consolidated statements of operations. The net book value of capitalized internally-developed software was $3.3 million and $2.4 million at December 31, 2014 and 2013, respectively.
Capitalized Content Development Costs
The Company works with each client's faculty members to develop and maintain educational content that is delivered to their students through Online Campus. The online content developed jointly by the Company and its clients consists of subjects chosen and taught by clients' faculty members and incorporates references and examples designed to remain relevant over extended periods of time. Online delivery of the content, combined with live, face-to-face instruction, provides the Company with rapid user feedback that it uses to make ongoing corrections, modifications and improvements to the course content. The Company's clients retain all intellectual property rights to the developed content, although the Company retains the rights to the content packaging and delivery mechanisms. Much of the Company's new content development uses proven delivery platforms and is therefore primarily subject-specific in nature. As a result, a significant portion of content development costs qualify for capitalization due to the focus of the Company's development efforts on the unique subject matter of the content. Similar to on-campus programs offered by the Company's clients, the online degree programs enabled by the Company offer numerous courses for each degree. The Company therefore capitalizes its development costs on a course-by-course basis. As students must matriculate into a client program in order to take a course, revenues and identifiable cash flows are also measured at the client program level.
The Company develops content on a course-by-course basis in conjunction with the faculty for each client program. The clients and their faculty generally provide course outlines in the form of the curriculum, required textbooks, case studies and other reading materials, as well as presentations that are typically used in the on-campus setting. The Company is then responsible for, and incurs all of the expenses related to, the conversion of the materials provided by each client into a format suitable for delivery through Online Campus.
The content development costs that qualify for capitalization are third-party direct costs, such as videography, editing and other services associated with creating digital content. Additionally, the Company capitalizes internal payroll and payroll-related costs incurred to create and produce videos and other digital content utilized in the clients' programs for delivery via Online Campus. Capitalization ends when content has been fully developed by both the Company and the client, at which time amortization of the capitalized content development costs begins. The capitalized costs are recorded on a course-by-course basis and included in capitalized content costs on the consolidated balance sheets. These costs are amortized using the straight-line method over the estimated useful life of the respective capitalized content program, which is generally five years. The estimated useful life corresponds with the Company's planned curriculum refresh rate. This refresh rate is consistent with expected curriculum refresh rates as cited by program faculty members for similar on-campus programs. It is reasonably possible that developed content could be refreshed before the estimated useful lives are complete.
Impairment of Long-Lived Assets
The Company reviews long-lived assets, which consist of property and equipment and capitalized content development costs, for impairment whenever events or changes in circumstances indicate the carrying value of an asset may not be recoverable. Recoverability of a long-lived asset is measured by a comparison of the carrying value of an asset or asset group to the future undiscounted net cash flows expected to be generated by that asset or asset group. If such assets are not recoverable, the impairment to be recognized is measured by the amount by which the carrying value of an asset exceeds the estimated fair value (discounted cash flow) of the asset or asset group. In order to assess the recoverability of the capitalized content development costs, the costs are grouped by program, which is the lowest level of independent cash flows. The Company's impairment analysis is based upon forecasted financial and operational results. The actual results could vary from the Company's forecasts, especially in relation to recently launched programs. For the years ended December 31, 2014 and 2012, no impairment of long-lived assets was deemed to have occurred. In December 2013, the Company evaluated the recoverability of its capitalized assets and determined that the estimated carrying value of one asset group exceeded its net realizable value. The Company determined that these capitalized amounts were not recoverable, performed an impairment assessment and recorded an impairment charge of $0.8 million in the fourth quarter of 2013.
Other Non-Current Assets
Other non-current assets consist primarily of intangible assets associated with the Company's registered domain names and security deposits on leased office facilities. Additional other non-current assets consist of deferred financing costs which were incurred by the Company directly in connection with obtaining its revolving line of credit. These deferred financing costs are amortized over a useful life equal to the term of the underlying line of credit. Until April 2, 2014, other non-current assets also consisted of costs the Company deferred which were incurred directly in connection with its IPO. These deferred IPO costs partially offset the cash proceeds received from the IPO.
Total other non-current assets consisted of the following as of:
		December 31,
		2014			2013
		(in thousands)
Deferred IPO Costs		$	—		$	1,781
Deferred financing costs			317			634
Other non-current assets			1,149			911
Total other non-current assets		$	1,466		$	3,326
Refunds Payable
The Company records a refunds payable liability related to the amounts owed to clients as a result of students defaulting on their payments to clients. The Company may receive its portion of net program proceeds prior to a client collecting the full amount of tuition and applicable fees from its students. The Company calculates the refunds payable liability by estimating the future amounts owed to a client resulting from non-payment by students. The Company's estimate is based on historical collection experience, market and income trends, and a review of the client's accounts receivable aging.
Rebate Reserve
The Company has recorded a rebate reserve liability that results from having offered students who first enrolled in a specific Master of Arts in Teaching program between April 2009 and June 2011 a rebate if they complete their degree and teach in a designated low-income school district for five consecutive years within the first six years after graduation. The Company accounts for the rebate reserve as a contingent sales incentive and has recorded a rebate reserve liability to recognize the obligation to rebate amounts to students who satisfactorily complete the rebate requirements.
Advances to Clients
The Company is contractually obligated to pay advances to certain of its clients in order to fund start-up expenses of the program on behalf of the client. Advances to clients are stated at realizable value. The advances are repaid to the Company on terms as required in the respective agreements. The Company recognizes imputed interest income on these advance payments when there is a significant amount of imputed interest.
Comprehensive Loss
The Company's net loss equals comprehensive loss for all periods presented as the Company has no material components of other comprehensive income.
Stock-Based Compensation
The Company accounts for stock-based compensation awards based on the fair value of the award as of the grant date. For awards subject to service-based vesting conditions, the Company recognizes stock-based compensation expense on a straight-line basis over the awards' requisite service period, adjusted for estimated forfeitures. For awards subject to both performance and service-based vesting conditions, the Company recognizes stock-based compensation expense using an accelerated recognition method when it is probable that the performance condition will be achieved.
See Note 10 for a discussion of assumptions used in calculating the fair value of stock options.
Basic and Diluted Loss per Common Share
The Company uses the two-class method to compute net loss per common share because the Company has issued securities, other than common stock, that contractually entitle the holders to participate in dividends and earnings of the Company. The two-class method requires earnings for the period to be allocated between common stock and participating securities based upon their respective rights to receive distributed and undistributed earnings. Holders of each series of the Company's redeemable convertible preferred stock (prior to their conversion to common stock) were entitled to participate in distributions, when and if declared by the board of directors, that are made to common stockholders, and as a result are considered participating securities.
Under the two-class method, for periods with net income, basic net income per common share is computed by dividing the net income attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period. Net income attributable to common stockholders is computed by subtracting from net income the portion of current year earnings that the participating securities would have been entitled to receive pursuant to their dividend rights had all of the year's earnings been distributed. No such adjustment to earnings is made during periods with a net loss, as the holders of the participating securities have no obligation to fund losses. Diluted net loss per common share is computed under the two-class method by using the weighted-average number of shares of common stock outstanding, plus, for periods with net income attributable to common stockholders, the potential dilutive effects of stock options and warrants. In addition, the Company analyzes the potential dilutive effect of the outstanding participating securities under the "if-converted" method when calculating diluted earnings per share, in which it is assumed that the outstanding participating securities convert into common stock at the beginning of the period. The Company reports the more dilutive of the approaches (two-class or "if-converted") as its diluted net income per share during the period. Due to net losses for the years ended December 31, 2014, 2013 and 2012, basic and diluted loss per share were the same, as the effect of potentially dilutive securities would have been anti-dilutive.
Recent Accounting Pronouncements
In July 2013, the Financial Accounting Standards Board ("FASB") issued ASU No. 2013-11, Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists, which is effective for interim or annual periods beginning after December 15, 2013. This guidance provides financial statement presentation guidance on whether an unrecognized tax benefit must be presented as either a reduction to a deferred tax asset or separately as a liability. The Company adopted this new guidance on January 1, 2014 and the adoption did not have a material impact on the Company's financial condition, results of operations or disclosures.
On May 28, 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. The new standard is effective for the Company on January 1, 2017. Early application is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU No. 2014-09 will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting.

Property_and_Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2014
Property and Equipment
Property and Equipment	3. Property and Equipment
	Property and equipment consisted of the following as of (in thousands):
		December 31,
		2014			2013
	Internally-developed software	$	7,820		$	5,516
	Computer hardware		3,016			2,082
	Furniture and office equipment		1,104			774
	Leasehold improvements		1,801			1,494
	Total		13,741			9,866
	Accumulated depreciation and amortization		(6,986	)		(4,635	)
	Property and equipment, net	$	6,755		$	5,231
	Depreciation and amortization expense of property and equipment was $2.4 million, $2.1 million and $1.3 million for the years ended December 31, 2014, 2013 and 2012, respectively.

Capitalized_Content_Developmen

Capitalized Content Development Costs	12 Months Ended
	Dec. 31, 2014
Capitalized Content Development Costs
Capitalized Content Development Costs	4. Capitalized Content Development Costs
	Capitalized content development costs consisted of the following as of (in thousands):
		December 31,
		2014			2013
	Capitalized content development costs	$	16,835		$	11,816
	Capitalized content development costs in process		3,699			1,961
	Accumulated amortization		(7,379	)		(4,873	)
	Capitalized content development costs, net	$	13,155		$	8,904
	The Company recorded amortization expense related to capitalized content development costs of $3.2 million, $2.2 million and $1.5 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	As of December 31, 2014, the estimated future amortization expense for the capitalized content development costs is as follows (in thousands):
	2015	$	3,017
	2016		2,577
	2017		1,983
	2018		1,426
	2019		453
	Total	$	9,456

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies
Commitments and Contingencies	5. Commitments and Contingencies
	Line of Credit
	On April 5, 2012, the Company secured a revolving line of credit from a bank for an aggregate borrowing base not to exceed $10.0 million. The Company never borrowed under this line of credit. On December 31, 2013, the Company entered into a new credit agreement which replaced its prior line of credit with a new revolving line of credit with an aggregate borrowing base not to exceed $37.0 million. On January 21, 2014, the Company borrowed $5.0 million under this line of credit and repaid this borrowing in full on February 18, 2014; therefore, no amounts were outstanding as of December 31, 2014. Under this revolving line of credit, the Company has the option of borrowing funds subject to (i) a base rate, which is equal to 1.5% plus the greater of Comerica Bank's prime rate, the federal funds rate plus 1% or the 30 day LIBOR plus 1%, or (ii) LIBOR plus 2.5%. For amounts borrowed under the base rate, the Company may make interest-only payments quarterly, and may prepay such amounts with no penalty. For amounts borrowed under LIBOR, the Company makes interest-only payments in periods of one, two and three months and will be subject to a prepayment penalty if such borrowed amounts are repaid before the end of the interest period.
	Borrowings under the line of credit are collateralized by substantially all of the Company's assets. The availability of borrowings under this credit line is subject to compliance with reporting and financial covenants, including, among other things, that the Company achieves specified minimum three-month trailing revenue levels during the term of the agreement and specified minimum six-month trailing profitability levels for some client programs, measured quarterly. In addition, the Company is required to maintain a minimum adjusted quick ratio, which measures short term liquidity, of at least 1.10 to 1.00.
	The covenants under the line of credit also place limitations on the Company's ability to incur additional indebtedness or to prepay permitted indebtedness, grant liens on or security interests in its assets, carry out mergers and acquisitions, dispose of assets, declare, make or pay dividends, make capital expenditures in excess of specified amounts, make investments, loans or advances, enter into transactions with affiliates, amend or modify the terms of material contracts, or change its fiscal year. If the Company is not in compliance with the covenants under the line of credit, after any opportunity to cure such non-compliance, or it otherwise experiences an event of default under the line of credit, the lenders may require repayment in full of all principal and interest outstanding. If the Company fails to repay such amounts, the lenders could foreclose on the assets pledged as collateral under the line of credit. The Company is currently in compliance with all such covenants.
	Legal Contingencies
	From time to time, the Company may become involved in legal proceedings or other contingencies in the ordinary course of its business. The Company is not presently involved in any legal proceeding or other contingency that, if determined adversely to it, would individually or in the aggregate have a material adverse effect on its business, operating results, financial condition or cash flows. Accordingly, the Company does not believe that there is a reasonable possibility that a material loss exceeding amounts already recognized may have been incurred as of the date of the balance sheets presented herein.
	Program Marketing and Sales Commitments
	Certain of the agreements entered into between the Company and its clients require the Company to commit to meet certain staffing and spending investment thresholds related to program marketing and sales activities. In addition, one of these agreements requires the Company to invest up to agreed upon levels in marketing this program to achieve specified program performance. The Company believes it is currently in compliance with all such commitments.
	Operating Leases
	The Company leases office facilities under non-cancelable operating leases in California, New York, Maryland, North Carolina and Hong Kong. The Company also leases furniture and office equipment under non-cancelable leases. As of December 31, 2014, the future minimum lease payments (net of aggregate expected sublease payments of $0.6 million) were as follows (in thousands):
	2015	$	2,772
	2016		2,643
	2017		2,466
	2018		1,809
	2019		821
	Thereafter		494
	Total future minimum lease payments	$	11,005
	The future minimum lease payments due under non-cancelable operating lease arrangements contain fixed 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 has been reported in other non-current liabilities in the accompanying consolidated balance sheets. The deferred rent liability related to these leases totaled $0.5 million and $0.5 million as of December 31, 2014 and 2013, respectively.
	Total rent expense (net of sublease income of $0.3 million, $0.3 million and $0.3 million) for the years ended December 31, 2014, 2013 and 2012 was $2.6 million, $2.1 million and $1.7 million, respectively.
	Payments to Clients
	The Company is contractually obligated to make fixed payments to certain of its clients in exchange for various intellectual property and other rights. As of December 31, 2014, the future minimum payments to the Company's clients for intellectual property and other rights were as follows (in thousands):
	2015	$	500
	2016		800
	2017		800
	2018		300
	2019		300
	Thereafter		2,700
	Total future minimum payments to clients	$	5,400

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Taxes
Income Taxes	6. Income Taxes
	The components of loss before income taxes for the years ended December 31 were as follows (in thousands):
		2014			2013			2012
	Domestic	$	(28,999	)	$	(27,953	)	$	(23,113	)
	Total loss before income taxes	$	(28,999	)	$	(27,953	)	$	(23,113	)
	A reconciliation between the Company's statutory federal income tax rate and the effective tax rate for the years ended December 31, is as follows:
		2014			2013			2012
	U.S. statutory federal income tax rate		35	%		35	%		35	%
	Increase (decrease) resulting from:
	U.S. state income taxes, net of federal benefits		5.8			7.3			5.3
	Non-deductible expenses		(2.8	)		(2.1	)		(2.1	)
	Change in valuation allowance		(32.4	)		(39.9	)		(38.1	)
	Other		(5.6	)		(0.3	)		(0.1	)
	Effective tax rate		0	%		0	%		0	%
	The significant components of the Company's deferred tax assets and liabilities as of December 31 are as follows (in thousands):
		2014			2013
	Deferred tax assets:
	Accrued expenses and other	$	3,556		$	1,501
	Rebate reserve		264			677
	Deferred rent		212			211
	Stock-based compensation		2,782			797
	Net operating loss carryforwards		46,264			37,874
	Valuation allowance		(44,309	)		(34,921	)
	Total deferred tax assets	$	8,769		$	6,139
	Deferred tax liabilities:
	Prepaid expenses and other	$	(1,344	)	$	(462	)
	Capitalized content development costs		(5,439	)		(3,841	)
	Capitalized software development costs		(1,346	)		(1,034	)
	Property and equipment		(640	)		(802	)
	Total deferred tax liabilities	$	(8,769	)	$	(6,139	)
	Net deferred tax assets/liabilities	$	—		$	—
	Income taxes are accounted for under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that are included in the financial statements. Deferred tax assets are subject to periodic recoverability assessments. Recognition of deferred tax assets is appropriate only if the likelihood of realization of such assets is more likely than not to occur. At December 31, 2014 and 2013, the Company had federal net operating loss ("NOL") carryforwards of approximately $123.4 million and $86.0 million, respectively, which expire between 2029 and 2034. The gross amount of the state NOL carryforwards is equal to or less than the federal NOL carryforwards and expires over various periods based on individual state tax laws. A full valuation allowance has been established to offset the net deferred tax assets. The total increase in the valuation allowance was $9.4 million for the year ended December 31, 2014, as the Company has not generated taxable income since inception and does not have sufficient deferred tax liabilities to recover the deferred tax assets. The utilization of the NOL carryforwards to reduce future income taxes will depend on the Company's ability to generate sufficient taxable income prior to the expiration of the NOL carryforwards. In addition, a certain portion of the above NOL carryforwards may be subject to Internal Revenue Code section 382 limitations, which may limit their future use.
	The Company completed an analysis of the stock ownership changes through April 30, 2014, and determined that there has not been an ownership change prior to that date. However, the Company has not completed an analysis to determine what, if any, impact any ownership change after April 30, 2014 has had on the ability to utilize NOL carryforwards. The Company has experienced a number of transactions subsequent to April 30, 2014, which could lead to a limitation of its NOL carryforwards under section 382 of the Internal Revenue Code. The Company intends to complete a study through December 31, 2014, regarding this limitation in the next twelve months. It is reasonably possible that the results of the study will reduce the reported NOL carryforwards and other deferred tax assets.
	The Company has estimated its annual effective tax rate for the full fiscal year 2014 and 2013 and applied that rate to its income before income taxes in determining its provision for income taxes. The Company also recorded discrete items in each respective period as appropriate. The Company's effective tax rate for the years ended December 31, 2014 and 2013 was 0%.
	The Company applies the provisions of ASC 740-10 to uncertain tax positions. ASC 740-10 clarifies accounting for income taxes by prescribing a minimum probability threshold that a tax position must meet before a financial statement benefit is recognized. If the probability for sustaining a tax position is greater than 50%, then the tax position is warranted and recognition should be at the highest amount which would be expected to be realized upon settlement. The Company did not identify any tax positions that would be required for inclusion in the financial statements. As of December 31, 2014, the Company had not made any changes to its tax positions since December 31, 2013.
	The Company recognizes interest and penalties related to uncertain tax positions in income tax expense. As of December 31, 2014 and 2013, the Company had no accrued interest or penalties related to uncertain tax positions.
	The Company has analyzed its filing positions in all significant federal, state and foreign jurisdictions where it is required to file income tax returns, as well as open tax years in these jurisdictions. With few exceptions, the Company is no longer subject to U.S. federal, state and local tax examinations by tax authorities for the years prior to 2010, though the NOL carryforwards can be adjusted upon audit and could impact taxes owed in open tax years. No income tax returns are currently under examination by the taxing authorities.

Redeemable_Convertible_Preferr

Redeemable Convertible Preferred Stock	12 Months Ended
	Dec. 31, 2014
Redeemable Convertible Preferred Stock
Redeemable Convertible Preferred Stock	7. Redeemable Convertible Preferred Stock
	The following table summarizes the Company's issuances of redeemable convertible preferred stock:
	Issue Date	Series		Purchase			Number of			Conversion
				Price per			Shares			Price per
				Share						Share
	Jun-09	Series A		$	1.27			10,033,976		$	1.27
	Feb-10	Series B		$	4.46			5,057,901		$	4.46
	Mar-11	Series C		$	7.34			4,429,601		$	7.34
	Mar-12	Series D		$	7.81			3,339,902		$	7.81
	Jan-13	Series D		$	7.81			639,828		$	7.81
	Series A, Series B, Series C and Series D redeemable convertible preferred stock are collectively referred to as the "Preferred Stock" and individually as the "Series A," "Series B," "Series C" and "Series D." Each of the purchase prices per share above is referred to as the Original Issue Price, and excludes the cost of issuance. Any costs incurred in connection with the issuance of the various classes of Preferred Stock have been recorded as a reduction of the carrying amount of the Preferred Stock and were accreted through a charge to additional paid-in capital through April 2, 2014.
	Summary of Activity
	The following table presents a summary of activity for the redeemable convertible preferred stock issued and outstanding for the periods presented below:
		Redeemable Convertible Preferred Stock
		Series A			Series B			Series C			Series D			Total
														Amount
		(in thousands)
	Balance, December 31, 2011	$	12,105		$	21,927		$	32,314		$	—		$	66,346
	Issuance of redeemable convertible preferred stock net of issuance costs		—			—			—			26,021			26,021
	Accretion of issuance costs on redeemable convertible preferred stock		139			141			45			14			339
	Balance, December 31, 2012		12,244			22,068			32,359			26,035			92,706
	Issuance of redeemable convertible preferred stock net of issuance costs		—			—			—			4,994			4,994
	Accretion of issuance costs on redeemable convertible preferred stock		140			142			46			19			347
	Balance, December 31, 2013		12,384			22,210			32,405			31,048			98,047
	Accretion of issuance costs on redeemable convertible preferred stock		36			36			12			5			89
	Conversion of preferred stock into common stock		(12,420	)		(22,246	)		(32,417	)		(31,053	)		(98,136	)
	Balance, December 31, 2014	$	—		$	—		$	—		$	—		$	—
	Redemption Rights
	The Preferred Stock shares were redeemable at the election of the Preferred Stock holders. On April 3, 2012, the Company amended its Amended and Restated Certificate of Incorporation to change the earliest possible Preferred Stock redemption date to any date after June 19, 2016, but within ninety days after the receipt of a written request from at least 75% of the holders of the outstanding shares of the respective series of Preferred Stock. Upon closing of the Company's IPO on April 2, 2014, all outstanding shares of redeemable convertible preferred stock automatically converted into an aggregate of 23,501,208 shares of common stock. No shares of redeemable convertible preferred stock were authorized, issued or outstanding at December 31, 2014. As of December 31, 2013, the redemption values of the Series A, B, C, and D Preferred Stock were $12.7 million, $22.6 million, $32.5 million and $31.1 million, respectively.
	Conversion Rights
	The Preferred Stock was convertible, at the option of the holder, into shares of common stock at a ratio equal to the Original Issue Price for such series divided by the conversion price for such series. Each series was convertible on a one-for-one basis. The conversion price for each series of Preferred Stock was subject to adjustment in the event of any stock dividend, stock split, combination of shares, reorganization, recapitalization, reclassification or similar event.
	Additionally, each share of Preferred Stock would automatically convert into common stock, at the then-current conversion price for such series, upon the earliest to occur of (i) immediately prior to the closing of a public offering of shares of the Company's common stock resulting in a deemed total market valuation for the Company of $330 million, based on the public offering price, and which results in aggregate cash proceeds to the Company of not less than $50 million, or (ii) the date specified by vote or written consent of (a) the holders of at least 662/3% of the voting power of the outstanding shares of Series A Preferred Stock, voting together as a class, (b) the holders of at least a majority of the voting power of the outstanding shares of Series B Preferred Stock, voting together as a class, (c) the holders of at least 60% of the voting power of the outstanding shares of Series C Preferred Stock, voting together as a class, and (d) the holders of at least 60% of the voting power of the outstanding shares of Series D Preferred Stock, voting together as a class.
	Voting Rights
	The holders of the Preferred Stock were entitled to the number of votes equal to the number of shares of common stock into which their shares of Preferred Stock are convertible. Certain transactions and actions required a minimum voting consent of the holders of the shares of the outstanding Preferred Stock, as set forth in the Company's Amended and Restated Certificate of Incorporation.
	The holders of the common stock have the right to one vote per share.
	Dividend Rights
	The holders of the Preferred Stock were entitled to receive dividends on a pari passu basis on each outstanding share of preferred stock (subject to adjustment in the event of any stock splits, stock dividends, reclassifications or similar events), payable in preference and priority to any declaration or payment of any dividend on the common stock of the Company. As of December 31, 2013, the dividends were payable at the rate of (i) $0.101512 per share per year on each outstanding share of Series A Preferred Stock; (ii) $0.356896 per share per year on each outstanding share of Series B Preferred Stock; (iii) $0.587307 per share per year on each outstanding share of Series C Preferred Stock; and (iv) $0.625168 per share per year on each outstanding share of Series D Preferred Stock. The dividends were payable when and if declared by the board of directors and are noncumulative. No dividends were declared on the Preferred Stock through April 2, 2014.
	The holders of the common stock are entitled to receive dividends if and when declared by the Company, but not until all dividends on the Preferred Stock had been either paid or declared and the Company had set aside the funds to pay those dividends declared.
	Liquidation Rights
	In the event of any liquidation, dissolution or winding up of the Company, whether voluntary or involuntary (each, a "Liquidation Event"), the holders of Series B, Series C, and Series D were entitled to receive in preference to the holders of Series A an amount per share equal to the respective Original lssue Price plus any declared and unpaid dividends.
	If the assets of the Company were insufficient to make payment in full, the assets would be distributed ratably in proportion to the full amounts to which the respective stockholders would otherwise be entitled. Thereafter, the holders of Series A shares were entitled to receive an amount per share equal to the Series A Original lssue Price plus all declared and unpaid dividends.
	After the payment of the full liquidation preferences of the preferred Stock as set forth above, the remaining assets of the Company available for distribution in such Liquidation Event, if any, were to be distributed ratably to the holders of the Common Stock.

Common_Stock_and_Preferred_Sto

Common Stock and Preferred Stock Reserved for Future Issuance	12 Months Ended
	Dec. 31, 2014
Common Stock and Preferred Stock Reserved for Future Issuance
Common Stock and Preferred Stock Reserved for Future Issuance	8. Common Stock and Preferred Stock Reserved for Future Issuance
	Immediately upon the closing of the IPO on April 2, 2014, the Company's certificate of incorporation was amended and restated to, among other things, authorize 200,000,000 shares of common stock and 5,000,000 shares of preferred stock. As of December 31, 2014, the Company was authorized to issue 205,000,000 total shares of capital stock, consisting of 200,000,000 shares of common stock and 5,000,000 shares of preferred stock. At December 31, 2014, the Company had reserved a total of 7,802,706 of its authorized shares of common stock for future issuance as follows:
	Outstanding stock options	5,850,211
	Possible future issuance under equity incentive plans	959,830
	Outstanding restricted stock units	992,665
	Total common shares reserved for future issuance	7,802,706

Warrants

Warrants	12 Months Ended
	Dec. 31, 2014
Warrants
Warrants	9. Warrants
	In connection with the line of credit secured in April 2012, the Company issued a warrant to purchase 12,797 shares of the Company's Series D redeemable convertible preferred stock with an exercise price of $7.81 per share and an expiration date in 2022. The warrant was valued at $74 thousand on the date of grant and at $19 thousand as of December 31, 2013.
	In connection with the line of credit secured in December 2013, the Company issued a warrant to purchase 71,021 shares of the Company's Series D redeemable convertible preferred stock with an exercise price of $7.81 per share and an expiration date in 2023. The warrant was valued at $107 thousand as of December 31, 2013.
	As of December 31, 2013, each of the Series D warrants were classified as a liability in the accompanying consolidated balance sheets and adjusted to fair value due to the fact that they were exercisable into redeemable convertible preferred securities.
	Upon the closing of the Company's IPO on April 2, 2014, the warrants to purchase Series D redeemable convertible preferred stock automatically converted into warrants to purchase common stock and the liability at its then fair value of $821 thousand was reclassified to additional paid-in capital. Prior to April 2, 2014, the inputs to the fair value model for the warrants were considered Level 3 inputs under ASC 820, Fair Value Measurements and Disclosures, and all changes in the fair value of the warrants were recorded as a component of interest expense. The Company recorded interest expense of $695 thousand for the year ended December 31, 2014 and reductions of interest expense of $33 thousand and $22 thousand for the years ended December 31, 2013 and 2012, respectively, related to the fair value adjustment of the warrants.
	On May 22, 2014, the holder of the warrants issued a notice of exercise to the Company to purchase 83,818 shares of common stock. In lieu of payment of the exercise price, the Company withheld from issuance a number of shares equal to the full exercise price divided by the price per share of the Company's common stock as measured on a volume weighted-average price basis over the 10-day trading period immediately prior to May 22, 2014. Consequently, the exercise of the warrants resulted in the issuance of 32,709 shares of the Company's common stock to the holder of the warrants, which represents a non-cash financing activity for purposes of the consolidated statement of cash flows.

StockBased_Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2014
Stock-Based Compensation
Stock-Based Compensation	10. Stock-Based Compensation
	The Company provides equity-based compensation awards to employees, non-employees and directors for the purpose of providing an effective means for attracting, retaining and motivating such individuals, and to provide them with incentives to exert maximum efforts for the success of the Company, and provide a means by which they may benefit from increases in value of the Company's common stock. The Company maintains two share-based compensation plans: the 2014 Equity Incentive Plan (the "2014 Plan") and the 2008 Stock Incentive Plan (the "2008 Plan"). Upon the effective date of the 2014 Plan in January 2014, the Company ceased using the 2008 Plan to grant new equity awards, and began using the 2014 Plan for grants of new equity awards.
	2014 Plan
	In February 2014, the Company's stockholders approved the 2014 Plan. The 2014 Plan provides for the grant of incentive stock options to the Company's employees and its parent and subsidiary corporations' employees, and for the grant of nonstatutory stock options, restricted stock awards, restricted stock unit awards, stock appreciation rights, performance stock awards and other forms of stock compensation to the Company's employees, consultants and directors. The 2014 Plan also provides for the grant of performance cash awards to the Company's employees, consultants and directors.
	Authorized Shares.    A total of 2,800,000 shares of the Company's common stock were initially reserved for issuance pursuant to the 2014 Plan. In addition, the shares reserved for issuance under the 2014 Plan include (a) those shares reserved but unissued under the 2008 Plan, and (b) shares returned to the 2008 Plan as the result of expiration or termination of awards (provided that the maximum number of shares that may be added to the 2014 Plan pursuant to (a) and (b) is 5,943,348 shares). The number of shares of the Company's common stock that may be issued under the 2014 Plan will automatically increase on January 1st of each year, for a period of ten years, from January 1, 2015 continuing through January 1, 2024, by 5% of the total number of shares of the Company's common stock outstanding on December 31st of the preceding calendar year, or a lesser number of shares as may be determined by the Company's board of directors.
	In addition, shares subject to outstanding stock awards granted under the 2008 Plan and 2014 Plan that (i) expire or terminate for any reason prior to exercise or settlement; (ii) are forfeited because of the failure to meet a contingency or condition required to vest such shares or otherwise return to the Company; or (iii) are reacquired, withheld (or not issued) to satisfy a tax withholding obligation in connection with an award or to satisfy the purchase price or exercise price of a stock award, return to the 2014 Plan's share reserve and become available for future grant under the 2014 Plan, up to the maximum number of shares of 5,943,348.
	As of December 31, 2014, the Company had 959,830 shares reserved for issuance under the 2014 Plan. Further, as of December 31, 2014, under the 2014 Plan, options to purchase 1,197,741 shares of the Company's common stock were outstanding at a weighted-average exercise price of $11.28 per share and 992,665 restricted stock units were outstanding. On January 1, 2015, the shares available for issuance increased by 2,036,503 pursuant to the automatic share reserve increase provision under the 2014 Plan.
	2008 Plan
	In October 2008, the Company's stockholders approved the Company's 2008 Plan. The 2008 Plan was most recently amended on May 8, 2013. The 2008 Plan provided for the grant of incentive stock options to the Company's employees and the employees of the Company's subsidiaries, and for the grant of nonstatutory stock options, restricted stock awards and deferred stock awards to the Company's employees, directors and consultants. Upon the effective date of the 2014 Plan, the Company ceased using the 2008 Plan to grant new equity awards, and began using the 2014 Plan for grants of new equity awards. Accordingly, as of January 30, 2014, no shares were available for future grant under the 2008 Plan. However, the 2008 Plan will continue to govern the terms and conditions of outstanding awards granted thereunder.
	As of December 31, 2014, options to purchase 4,652,470 shares of the Company's common stock were outstanding under the 2008 Plan at a weighted-average exercise price of $3.87 per share.
	Stock-based Compensation Expense
	Stock-based compensation expense related to stock-based awards is included in the following line items in the accompanying consolidated statements of operations:
		Year Ended December 31,
		2014			2013		2012
		(in thousands)
	Servicing and support	$	1,468		$	364	$	180
	Technology and content development		794			159		43
	Program marketing and sales		676			178		162
	General and administrative		4,589			1,725		1,010
	Total stock-based compensation expense	$	7,527		$	2,426	$	1,395
	Stock Options
	The terms of stock option grants, including the exercise price per share and vesting periods, are determined by the Company's board of directors or the compensation committee thereof. Stock options are granted at exercise prices of not less than the estimated fair market value of the Company's common stock at the date of grant. Stock options are generally subject to service-based vesting conditions and vest at various times from the date of the grant, with most options vesting in tranches, generally over a period of four years. Stock options granted under the 2014 Plan and the 2008 Plan are subject to service-based vesting conditions, and generally expire ten years from the grant date.
	The Company values stock options using the Black-Scholes-Merton option pricing model, which requires the input of subjective assumptions, including the risk-free interest rate, expected life of the option, expected stock price volatility and dividend yield. Additionally, the recognition of expense requires estimation of the number of options that will ultimately vest and those that will be forfeited. The Company estimates the expected forfeitures of share-based awards at the grant date and recognizes the compensation cost only for those awards expected to vest.
	The risk-free interest rate assumption is based upon observed interest rates for constant maturity U.S. Treasury securities consistent with the expected term of the Company's employee stock options. The expected life represents the period of time the stock options are expected to be outstanding and is based on the "simplified method." Under the "simplified method," the expected life of an option is presumed to be the mid-point between the vesting date and the end of the contractual term. The Company used the "simplified method" due to the lack of sufficient historical exercise data to provide a reasonable basis upon which to otherwise estimate the expected life of the stock options. Expected volatility is based on historical volatilities for publicly traded stock of comparable companies over the estimated expected life of the stock options. The Company assumed no dividend yield because dividends are not expected to be paid in the near future, which is consistent with the Company's history of not paying dividends.
	The following table summarizes the assumptions used for estimating the fair value of the stock options granted:
		Year Ended December 31,
		2014		2013		2012
	Risk-free interest rate	1.7% - 2.1%		0.9% - 2.0%		0.8% - 1.1%
	Expected term (years)	5.11 - 6.25		5.54 - 6.31		5.65 - 6.15
	Expected volatility	50% - 55%		55% - 58%		57% - 61%
	Dividend yield	0%		0%		0%
	Weighted-average grant date fair value	$5.71		$4.58		$1.91
	The following is a summary of the option activity:
		Number of			Weighted-Average		Weighted-Average		Aggregate
		Options			Exercise Price		Remaining		Intrinsic
					per Share		Contractual		Value
							Term (in years)		(in thousands)
	Outstanding balance at December 31, 2013		5,883,885		$	3.53		7.45	$	36,884
	Granted		1,319,110			11.23		8.65
	Exercised		(940,642	)		2.43		5.3
	Forfeited		(191,513	)		8.08
	Expired		(220,629	)		0.96
	Outstanding balance at December 31, 2014		5,850,211			5.39		7.33		83,487
	Exercisable at December 31, 2014		3,198,869			3.07		6.31		53,069
	Vested and expected to vest at December 31, 2014		5,649,272			5.27		7.28		81,287
	The total compensation cost related to the nonvested options not yet recognized as of December 31, 2014 was $9.6 million and will be recognized over a weighted-average period of approximately 2.3 years.
	The aggregate intrinsic value of the options exercised during the years ended December 31, 2014, 2013 and 2012 was $16.2 million, $1.8 million and $1.6 million, respectively.
	The following table summarizes by grant date the number of shares of common stock subject to stock options granted from January 1, 2014 to December 31, 2014, as well as the associated exercise price per share and the estimated fair value per share of the Company's common stock on the grant date.
	Grant Date	Number of			Exercise Price		Estimated
		Shares			per Share		Grant Date Fair
		Underlying					Value per Share
		Options
		Granted
	January 30, 2014		45,000		$	9.50	$	11.00
	March 6, 2014		1,128,430			11.00		11.00
	March 27, 2014		66,427			13.00		13.00
	April 11, 2014		44,334			12.94		12.94
	July 1, 2014		20,779			16.08		16.08
	August 5, 2014		10,000			13.64		13.64
	October 1, 2014		4,140			15.16		15.16
	Prior to the IPO, the Company determined for financial reporting purposes the estimated per share fair value of its common stock at various grant dates using contemporaneous valuations performed in accordance with the guidance outlined in the American Institute of Certified Public Accountants Practice Aid, "Valuation of Privately-Held Company Equity Securities Issued as Compensation," also known as the Practice Aid. In conducting the contemporaneous valuations, the Company used relevant information available and considered all objective and subjective factors that it believed to be relevant for each valuation conducted, including management's best estimate of the Company's business condition, prospects and operating performance at each valuation date.
	Restricted Stock Units
	Throughout 2014, the Company granted restricted stock units under the 2014 Plan to the Company's directors and certain of the Company's employees. The terms of the restricted stock unit grants under the 2014 Plan, including the vesting periods, are determined by the Company's board of directors or the compensation committee thereof. Restricted stock units are generally subject to service-based vesting conditions and vest at various times form the date of the grant, with most restricted stock units vesting in equal annual tranches, generally over a period of four years.
	The following is a summary of restricted stock unit activity:
	Number of			Weighted-
	Restricted			Average Grant
	Stock Units			Date Fair Value
Outstanding balance at December 31, 2013		—		$	—
Granted		1,089,286			11.41
Vested		—			—
Forfeited		(96,621	)		11.6
Outstanding balance at December 31, 2014		992,665			11.39
The total compensation cost related to the nonvested restricted stock units not yet recognized as of December 31, 2014 was $7.5 million and will be recognized over a weighted-average period of approximately 3.0 years.

Net_Loss_per_Share

Net Loss per Share	12 Months Ended
	Dec. 31, 2014
Net Loss per Share
Net Loss per Share	11. Net Loss per Share
	Diluted loss per share is the same as basic loss per share for all periods presented because the effects of potentially dilutive items were anti-dilutive given the Company's net loss. The following securities have been excluded from the calculation of weighted-average common shares outstanding because the effect is anti-dilutive for the years ended December 31, 2014, 2013 and 2012:
		Year Ended December 31,
		2014			2013			2012
	Redeemable convertible preferred stock:
	Series A		—			10,033,976			10,033,976
	Series B		—			5,057,901			5,057,901
	Series C		—			4,429,601			4,429,601
	Series D		—			3,979,730			3,339,902
	Warrants to purchase Series D redeemable convertible preferred stock		—			83,818			12,797
	Stock options		5,850,211			5,883,885			4,766,827
	Restricted stock units		992,665			—			—
	Basic and diluted net loss per share attributable to common stockholders is calculated as follows:
		Year Ended December 31,
		2014			2013			2012
	Numerator (in thousands):
	Net loss attributable to common stockholders	$	(29,088	)	$	(28,300	)	$	(23,452	)
	Denominator:
	Weighted-average common shares outstanding, basic and diluted		32,075,107			7,432,055			7,037,090
	Net loss per share attributable to common stockholders, basic and diluted	$	(0.91	)	$	(3.81	)	$	(3.33	)

Segment_and_Geographic_Informa

Segment and Geographic Information	12 Months Ended
	Dec. 31, 2014
Segment and Geographic Information
Segment and Geographic Information	12. Segment and Geographic Information
	Operating segments are defined as components of an enterprise for which discrete financial information is available that is evaluated regularly by the chief operating decision maker ("CODM") for purposes of allocating resources and evaluating financial performance. The Company's CODM reviews the financial information presented on a consolidated basis for purposes of allocating resources and evaluating financial performance. As such, the Company's operations constitute a single operating segment and one reportable segment. The Company offers similar services to substantially all of its clients, which primarily represent well-recognized nonprofit colleges and universities in the United States. Substantially all assets were held and all revenue was generated in the United States during all periods presented.

Retirement_Plan

Retirement Plan	12 Months Ended
	Dec. 31, 2014
Retirement Plan
Retirement Plan	13. Retirement Plan
	The Company has established a 401(k) plan for eligible employees to contribute up to 100% of their compensation, limited by the IRS-imposed maximum contribution amount. The Company matches 33% of each employee's contribution up to 6% of the employee's salary deferral. For the years ended December 31, 2014, 2013 and 2012, the Company made employer contributions of $0.6 million, $0.4 million and $0.3 million, respectively.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2014
Related Party Transactions
Related Party Transactions	14. Related Party Transactions
	The Company subleases office space to an entity related by virtue of common ownership by a major stockholder. The lease requires the subtenant to reimburse the Company for the allocated cost of the office space subleased. For the years ended December 31, 2014, 2013 and 2012, the Company recorded $0.3 million, $0.2 million and $0.2 million, respectively, as rental income from this related entity.
	The Company utilizes the marketing and event planning services of a company that is partially owned by one of the Company's executives. The Company recorded $1.6 million, $0.8 million and $0.4 million for the expenses incurred related to the services provided by this related party for the years ended December 31, 2014, 2013 and 2012, respectively. No material amounts were due to the related party or recorded in accounts payable on the consolidated balance sheets as of December 31, 2014 and 2013.
	As of December 31, 2012, the Company recorded a note receivable from one of its executives in the amount of $0.3 million. The note bore an interest rate of 2.18% and was due in full at the earliest of the employee's termination, a change in control of the Company, an IPO or October 2019. The note was secured by stock options to purchase an aggregate of 869,000 shares held by the executive. The note receivable was recorded as a related party receivable on the consolidated balance sheets. The note was repaid in full prior to December 31, 2013.

Quarterly_Financial_Informatio

Quarterly Financial Information ( Unaudited )	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information ( Unaudited )
Quarterly Financial Information ( Unaudited )	15. Quarterly Financial Information (unaudited, in thousands, except share and per share amounts)
	The following tables set forth certain unaudited quarterly financial data for 2014 and 2013. This unaudited information has been prepared on the same basis as the audited information included elsewhere in this Annual Report and includes all adjustments necessary to present fairly the information set forth therein. The operating results are not necessarily indicative of results for any future period.
		Three Months Ended
		March 31,			June 30,			September 30,			December 31,
		2014			2014			2014			2014
	Revenue	$	26,332		$	24,744		$	28,407		$	30,756
	Costs and expenses:
	Servicing and support		6,248			7,000			6,598			7,012
	Technology and content development		5,674			5,818			5,726			5,403
	Program marketing and sales		15,241			16,710			16,971			16,296
	General and administrative		5,436			5,708			6,303			5,973
	Total costs and expenses		32,599			35,236			35,598			34,684
	Loss from operations		(6,267	)		(10,492	)		(7,191	)		(3,928	)
	Other income (expense):
	Interest expense		(784	)		(134	)		(176	)		(119	)
	Interest income		1			31			30			30
	Total other income (expense)		(783	)		(103	)		(146	)		(89	)
	Net loss	$	(7,050	)	$	(10,595	)	$	(7,337	)	$	(4,017	)
	Net loss per share:
	Basic and diluted	$	(0.92	)	$	(0.27	)	$	(0.18	)	$	(0.10	)
	Weighted-average shares used in computing net loss per share:
	Basic and diluted		7,698,709			39,304,884			40,269,937			40,577,087
		Three Months Ended
		March 31,			June 30,			September 30,			December 31,
		2013			2013			2013			2013
	Revenue	$	19,134		$	18,691		$	20,499		$	24,803
	Costs and expenses:
	Servicing and support		5,018			5,656			5,842			6,202
	Technology and content development		3,235			4,596			5,113			6,528
	Program marketing and sales		11,770			13,695			15,412			13,226
	General and administrative		2,871			3,654			4,269			4,046
	Total costs and expenses		22,894			27,601			30,636			30,002
	Loss from operations		(3,760	)		(8,910	)		(10,137	)		(5,199	)
	Other income (expense):
	Interest expense		8			5			(1	)		15
	Interest income		6			10			5			5
	Total other income (expense)		14			15			4			20
	Net loss	$	(3,746	)	$	(8,895	)	$	(10,133	)	$	(5,179	)
	Net loss per share:
	Basic and diluted	$	(0.51	)	$	(1.20	)	$	(1.37	)	$	(0.69	)
	Weighted-average shares used in computing net loss per share:
	Basic and diluted		7,386,133			7,398,059			7,415,777			7,528,940

SCHEDULE_IIVALUATION_AND_QUALI

SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS	12 Months Ended
	Dec. 31, 2014
SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS
SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS	Schedule II—Valuation and Qualifying Accounts (in thousands)
		Balance at		Additions		Deductions			Balance at
		Beginning of		Charged to					End of
		Period		Expense/Against					Period
				Revenue
	Allowance for doubtful accounts:
	Year ended December 31, 2014	$	12	$	—	$	(12	)	$	—
	Year ended December 31, 2013		—		12		—			12
	Year ended December 31, 2012		—		—		—			—
		Balance at		Additions		Deductions			Balance at
		Beginning of		Charged to					End of
		Period		Expense/Against					Period
				Revenue
	Income tax valuation allowance:
	Year ended December 31, 2014	$	34,921	$	9,388	$	—		$	44,309
	Year ended December 31, 2013		23,864		11,057		—			34,921
	Year ended December 31, 2012		15,072		8,792		—			23,864

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2014

Significant Accounting Policies

Principles of Consolidation

Principles of Consolidation

The accompanying consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary and have been prepared in accordance with United States generally accepted accounting principles ("U.S. GAAP"). All intercompany accounts and transactions have been eliminated in consolidation.

Use of Estimates

Use of Estimates

The preparation of financial statements in accordance with U.S. GAAP requires management to make certain estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. On an ongoing basis, the Company evaluates its estimates, including those related to the useful lives of long-lived assets, fair value measurement and income taxes, among others. The Company bases its estimates on historical experience and on various other assumptions that it believes to be reasonable, the results of which form the basis for making judgments about the carrying value of assets and liabilities. Actual results could differ from those estimates.

Cash and Cash Equivalents

Cash and Cash Equivalents

Cash and cash equivalents consist of bank checking and money market accounts and investments in certificates of deposit that mature in less than three months. The Company considers all highly liquid marketable securities with maturities at the time of purchase of three months or less to be cash equivalents, and they are carried at fair value.

Revenue Recognition and Deferred Revenue

Revenue Recognition and Deferred Revenue

The Company recognizes revenue when all of the following conditions are met: (i) persuasive evidence of an arrangement exists, (ii) rendering of services is complete, (iii) fees are fixed or determinable and (iv) collection of fees is reasonably assured.

The Company primarily derives its revenue from long-term contracts that typically range from 10 to 15 years in length. Under these contracts, the Company enables access to its Platform to its clients and their faculty and students. The Company is entitled to a contractually specified percentage of net program proceeds from its clients. These net program proceeds represent gross proceeds billed by clients to students, less credit card fees and other specified charges the Company has agreed to exclude in certain of its client contracts. A refund allowance is established for the Company's share of tuition and fees ultimately uncollected by its clients. The Company also offered rebates to a group of students who enrolled in a specific client program between 2009 and 2011, which the Company will pay to the student if he or she completes the degree and certain post-graduation work requirements within a specified period of time. These rebates and refunds offset the net program proceeds recognized as revenue. Revenue is recognized ratably over the service period, which the Company defines as the first through the last day of classes for each semester in a client's program. The Company invoices its clients based on enrollment reports that are generated by its clients. In some instances, these enrollment reports are received prior to the conclusion of the drop/add period. In such cases, the Company establishes a reserve against revenue, if necessary, based on its estimate of changes in enrollments expected prior to the end of the drop/add period.

The Company generates substantially all of its revenue from multiple-deliverable contractual arrangements with its clients. Under each of these arrangements, the Company provides (i) access to Online Campus, which serves as a learning platform for its client's faculty and students and which also enables a comprehensive range of other client functions, (ii) access to operations applications which provide the content management, admissions application processing, customer relationship management, and other functionality necessary to effectively operate the Company's clients' programs and (iii) technology-enabled services that support the complete lifecycle of a higher education program, including attracting students, advising prospective students through the admissions application process, providing technical, success coaching and other support, facilitating accessibility to individuals with disabilities, and facilitating in-program field placements.

In order to treat deliverables in a multiple-deliverable contractual arrangement as separate units of accounting, deliverables must have standalone value upon delivery. The technology-enabled services within the Platform are provided primarily in support of programs delivered through Online Campus, and for students of the programs delivered through Online Campus. Accordingly, the Company has determined that no individual deliverable has standalone value upon delivery and, therefore, deliverables within the Company's multiple-deliverable arrangements do not qualify for treatment as separate units of accounting. Accordingly, the Company considers all deliverables to be a single unit of accounting and recognizes revenue from the entire arrangement over the term of the service period.

Advance payments are recorded as deferred revenue until services are delivered or obligations are met, at which time revenue is recognized. Deferred revenue as of a particular balance sheet date represents the excess of amounts received as compared to amounts recognized in revenue in the consolidated statements of operations as of the end of the reporting period, and such amounts are reflected as a current liability on the Company's consolidated balance sheets.

Advertising Costs

Advertising Costs

The Company expenses advertising costs as incurred. The amounts expensed for the years ended December 31, 2014, 2013 and 2012 were not material. The Company records its advertising costs as program marketing and sales expense in the Company's consolidated statements of operations.

Fair Value Measurements

Fair Value Measurements

The carrying amounts of certain assets and liabilities, including cash and cash equivalents, accounts receivable, accounts payable and accrued expenses and other current liabilities, approximate their respective fair values due to their short-term nature.

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date, based on the Company's principal or, in the absence of a principal, most advantageous, market for the specific asset or liability.

U.S. GAAP provides for a three-tier fair value hierarchy to classify and disclose all assets and liabilities measured at fair value on a recurring basis, as well as assets and liabilities measured at fair value on a non-recurring basis, in periods subsequent to their initial measurement. The fair value hierarchy requires the Company to use observable inputs when available, and to minimize the use of unobservable inputs when determining fair value. The three tiers are defined as follows:

•

Level 1—Observable inputs that reflect quoted market prices (unadjusted) for identical assets or liabilities in active markets;

•

Level 2—Observable inputs, other than quoted prices in active markets, that are observable either directly or indirectly in the marketplace for identical or similar assets and liabilities; and

•

Level 3—Unobservable inputs that are supported by little or no market data, which require the Company to develop its own assumptions about the assumptions market participants would use in pricing the asset or liability based on the best information available in the circumstances.

Assets and Liabilities Measured at Fair Value on a Recurring Basis

The Company evaluates its financial assets and liabilities subject to fair value measurements on a recurring basis to determine the appropriate level in which to classify them for each reporting period. This determination requires significant judgments to be made. The following tables summarize the conclusions reached as of December 31, 2014 and 2013:

Balance as of December 31, 2014

Total

Level 1

Level 2

Level 3

(in thousands)

Assets:

Cash equivalents

$

82,939

$

82,939

$

—

$

—

Liabilities:

Series D redeemable convertible preferred stock warrants

$

—

$

—

$

—

$

—

Balance as of December 31, 2013

Total

Level 1

Level 2

Level 3

(in thousands)

Assets:

Cash equivalents

$

3,357

$

3,357

$

—

$

—

Liabilities:

Series D redeemable convertible preferred stock warrants

$

126

$

—

$

—

$

126

Prior to converting to common stock warrants upon the closing of the IPO on April 2, 2014, the Company used an option pricing model to determine the fair value of the Series D redeemable convertible preferred stock warrants. The valuation required the input of subjective assumptions, including the risk-free interest rate, the value of the underlying securities and the expected stock price volatility. The risk-free interest rate assumption was based upon observed interest rates for constant maturity U.S. Treasury securities consistent with the term of the warrants. The expected stock price volatility assumption was based on historical volatilities for publicly traded stock of comparable companies over the term of the warrants. The value of the underlying securities assumption was based upon the market price of the Company's common stock as the redeemable convertible preferred stock warrants became convertible into shares of common stock upon closing of the IPO.

Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs

The following table presents the changes in the Company's Level 3 instruments measured at fair value on a recurring basis:

Series C

Series D

Warrant

Warrants

(in thousands)

Balance as of December 31, 2012

$

—

$

52

Issuance of warrant

—

107

Change in fair value of warrant liability

—

(33

)

Balance as of December 31, 2013

—

126

Change in fair value of warrant liability

—

695

Reclassification of warrant liability to additional paid-in capital

(821

)

Balance as of December 31, 2014

$

—

$

—

Accounts Receivable and Allowance for Doubtful Accounts

Accounts Receivable and Allowance for Doubtful Accounts

Accounts receivable are stated at realizable value. The Company extends a minimal amount of uncollateralized credit to its clients. The Company utilizes the allowance method to provide for doubtful accounts based on management's evaluation of the collectability of the amounts due. The Company's estimate is based on historical collection experience and a review of the current status of accounts receivable. Historically, actual write-offs for uncollectible accounts have not significantly differed from the Company's estimates. As of December 31, 2014 and 2013, the Company determined that no significant allowances for doubtful accounts were necessary.

Concentration of Credit Risk

Concentration of Credit Risk

Financial instruments that subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents and accounts receivable. All of the Company's cash is held at financial institutions that management believes to be of high credit quality. The Company's bank accounts exceed federally insured limits at times. The Company has not experienced any losses on cash to date. To manage accounts receivable risk, the Company evaluates the creditworthiness of its clients and maintains an allowance for doubtful accounts, if needed.

Three of the Company's clients accounted for the following percentages of revenue for the periods presented below:

Year Ended

December 31,

2014

2013

2012

Client A

55

%

69

%

78

%

Client B

14

16

15

Client C

13

12

7

Additionally, the Company's largest client accounted for 35% and 51% of the Company's accounts receivable balance as of December 31, 2014 and 2013, respectively. Further, two additional clients accounted for more than 10% of the Company's accounts receivable balance as of December 31, 2014, while one additional client accounted for more than 10% of the Company's accounts receivable balance as of December 31, 2013.

Property and Equipment

Property and Equipment

Property and equipment is stated at cost less accumulated depreciation and amortization. Computer software is included in property and equipment and consists of internally-developed software. Expenditures for major additions, construction and improvements are capitalized. Depreciation and amortization is expensed using the straight-line method over the estimated useful lives of the related assets, which range from three to five years for computer hardware and five to seven years for furniture and office equipment. Leasehold improvements are depreciated on a straight-line basis over the lesser of the remaining term of the leased facility or the estimated useful life of the improvement, which ranges from four to ten years. Useful lives of significant assets are periodically reviewed and adjusted prospectively to reflect the Company's current estimates of the respective assets' expected utility. Repair and maintenance costs are expensed as incurred.

The Company capitalizes certain costs associated with internally-developed software, primarily consisting of direct labor associated with creating the software. Software development projects generally include three stages: the preliminary project stage (all costs are expensed as incurred), the application development stage (certain costs are capitalized and certain costs are expensed as incurred) and the post-implementation/operation stage (all costs are expensed as incurred). Costs capitalized in the application development stage include costs of designing the application, coding, integrating the Company's and the university's networks and systems, and the testing of the software. Capitalization of costs requires judgment in determining when a project has reached the application development stage and the period over which the Company expects to benefit from the use of that software. Once the software is placed in service, these costs are depreciated on the straight-line method over the estimated useful life of the software, which is generally three years. Internal software development costs of $2.3 million, $1.3 million and $1.1 million were capitalized during the years ended December 31, 2014, 2013 and 2012, respectively. Amortization expense related to the capitalized internally-developed software was $1.4 million, $1.5 million and $0.9 million for the years ended December 31, 2014, 2013 and 2012, respectively, and is included in technology and content development costs in the accompanying consolidated statements of operations. The net book value of capitalized internally-developed software was $3.3 million and $2.4 million at December 31, 2014 and 2013, respectively.

Capitalized Content Development Costs

Capitalized Content Development Costs

The Company works with each client's faculty members to develop and maintain educational content that is delivered to their students through Online Campus. The online content developed jointly by the Company and its clients consists of subjects chosen and taught by clients' faculty members and incorporates references and examples designed to remain relevant over extended periods of time. Online delivery of the content, combined with live, face-to-face instruction, provides the Company with rapid user feedback that it uses to make ongoing corrections, modifications and improvements to the course content. The Company's clients retain all intellectual property rights to the developed content, although the Company retains the rights to the content packaging and delivery mechanisms. Much of the Company's new content development uses proven delivery platforms and is therefore primarily subject-specific in nature. As a result, a significant portion of content development costs qualify for capitalization due to the focus of the Company's development efforts on the unique subject matter of the content. Similar to on-campus programs offered by the Company's clients, the online degree programs enabled by the Company offer numerous courses for each degree. The Company therefore capitalizes its development costs on a course-by-course basis. As students must matriculate into a client program in order to take a course, revenues and identifiable cash flows are also measured at the client program level.

The Company develops content on a course-by-course basis in conjunction with the faculty for each client program. The clients and their faculty generally provide course outlines in the form of the curriculum, required textbooks, case studies and other reading materials, as well as presentations that are typically used in the on-campus setting. The Company is then responsible for, and incurs all of the expenses related to, the conversion of the materials provided by each client into a format suitable for delivery through Online Campus.

The content development costs that qualify for capitalization are third-party direct costs, such as videography, editing and other services associated with creating digital content. Additionally, the Company capitalizes internal payroll and payroll-related costs incurred to create and produce videos and other digital content utilized in the clients' programs for delivery via Online Campus. Capitalization ends when content has been fully developed by both the Company and the client, at which time amortization of the capitalized content development costs begins. The capitalized costs are recorded on a course-by-course basis and included in capitalized content costs on the consolidated balance sheets. These costs are amortized using the straight-line method over the estimated useful life of the respective capitalized content program, which is generally five years. The estimated useful life corresponds with the Company's planned curriculum refresh rate. This refresh rate is consistent with expected curriculum refresh rates as cited by program faculty members for similar on-campus programs. It is reasonably possible that developed content could be refreshed before the estimated useful lives are complete.

Impairment of Long-Lived Assets

Impairment of Long-Lived Assets

The Company reviews long-lived assets, which consist of property and equipment and capitalized content development costs, for impairment whenever events or changes in circumstances indicate the carrying value of an asset may not be recoverable. Recoverability of a long-lived asset is measured by a comparison of the carrying value of an asset or asset group to the future undiscounted net cash flows expected to be generated by that asset or asset group. If such assets are not recoverable, the impairment to be recognized is measured by the amount by which the carrying value of an asset exceeds the estimated fair value (discounted cash flow) of the asset or asset group. In order to assess the recoverability of the capitalized content development costs, the costs are grouped by program, which is the lowest level of independent cash flows. The Company's impairment analysis is based upon forecasted financial and operational results. The actual results could vary from the Company's forecasts, especially in relation to recently launched programs. For the years ended December 31, 2014 and 2012, no impairment of long-lived assets was deemed to have occurred. In December 2013, the Company evaluated the recoverability of its capitalized assets and determined that the estimated carrying value of one asset group exceeded its net realizable value. The Company determined that these capitalized amounts were not recoverable, performed an impairment assessment and recorded an impairment charge of $0.8 million in the fourth quarter of 2013.

Other Non-Current Assets

Other Non-Current Assets

Other non-current assets consist primarily of intangible assets associated with the Company's registered domain names and security deposits on leased office facilities. Additional other non-current assets consist of deferred financing costs which were incurred by the Company directly in connection with obtaining its revolving line of credit. These deferred financing costs are amortized over a useful life equal to the term of the underlying line of credit. Until April 2, 2014, other non-current assets also consisted of costs the Company deferred which were incurred directly in connection with its IPO. These deferred IPO costs partially offset the cash proceeds received from the IPO.

Total other non-current assets consisted of the following as of:

December 31,

2014

2013

(in thousands)

Deferred IPO Costs

$

—

$

1,781

Deferred financing costs

317

634

Other non-current assets

1,149

911

Total other non-current assets

$

1,466

$

3,326

Refunds Payable

Refunds Payable

The Company records a refunds payable liability related to the amounts owed to clients as a result of students defaulting on their payments to clients. The Company may receive its portion of net program proceeds prior to a client collecting the full amount of tuition and applicable fees from its students. The Company calculates the refunds payable liability by estimating the future amounts owed to a client resulting from non-payment by students. The Company's estimate is based on historical collection experience, market and income trends, and a review of the client's accounts receivable aging.

Rebate Reserve

Rebate Reserve

The Company has recorded a rebate reserve liability that results from having offered students who first enrolled in a specific Master of Arts in Teaching program between April 2009 and June 2011 a rebate if they complete their degree and teach in a designated low-income school district for five consecutive years within the first six years after graduation. The Company accounts for the rebate reserve as a contingent sales incentive and has recorded a rebate reserve liability to recognize the obligation to rebate amounts to students who satisfactorily complete the rebate requirements.

Advances to Clients

Advances to Clients

The Company is contractually obligated to pay advances to certain of its clients in order to fund start-up expenses of the program on behalf of the client. Advances to clients are stated at realizable value. The advances are repaid to the Company on terms as required in the respective agreements. The Company recognizes imputed interest income on these advance payments when there is a significant amount of imputed interest.

Comprehensive Loss

Comprehensive Loss

The Company's net loss equals comprehensive loss for all periods presented as the Company has no material components of other comprehensive income.

Stock-Based Compensation

Stock-Based Compensation

The Company accounts for stock-based compensation awards based on the fair value of the award as of the grant date. For awards subject to service-based vesting conditions, the Company recognizes stock-based compensation expense on a straight-line basis over the awards' requisite service period, adjusted for estimated forfeitures. For awards subject to both performance and service-based vesting conditions, the Company recognizes stock-based compensation expense using an accelerated recognition method when it is probable that the performance condition will be achieved.

See Note 10 for a discussion of assumptions used in calculating the fair value of stock options.

Basic and Diluted Loss per Common Share

Basic and Diluted Loss per Common Share

The Company uses the two-class method to compute net loss per common share because the Company has issued securities, other than common stock, that contractually entitle the holders to participate in dividends and earnings of the Company. The two-class method requires earnings for the period to be allocated between common stock and participating securities based upon their respective rights to receive distributed and undistributed earnings. Holders of each series of the Company's redeemable convertible preferred stock (prior to their conversion to common stock) were entitled to participate in distributions, when and if declared by the board of directors, that are made to common stockholders, and as a result are considered participating securities.

Under the two-class method, for periods with net income, basic net income per common share is computed by dividing the net income attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period. Net income attributable to common stockholders is computed by subtracting from net income the portion of current year earnings that the participating securities would have been entitled to receive pursuant to their dividend rights had all of the year's earnings been distributed. No such adjustment to earnings is made during periods with a net loss, as the holders of the participating securities have no obligation to fund losses. Diluted net loss per common share is computed under the two-class method by using the weighted-average number of shares of common stock outstanding, plus, for periods with net income attributable to common stockholders, the potential dilutive effects of stock options and warrants. In addition, the Company analyzes the potential dilutive effect of the outstanding participating securities under the "if-converted" method when calculating diluted earnings per share, in which it is assumed that the outstanding participating securities convert into common stock at the beginning of the period. The Company reports the more dilutive of the approaches (two-class or "if-converted") as its diluted net income per share during the period. Due to net losses for the years ended December 31, 2014, 2013 and 2012, basic and diluted loss per share were the same, as the effect of potentially dilutive securities would have been anti-dilutive.

Recent Accounting Pronouncements

Recent Accounting Pronouncements

In July 2013, the Financial Accounting Standards Board ("FASB") issued ASU No. 2013-11, Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists, which is effective for interim or annual periods beginning after December 15, 2013. This guidance provides financial statement presentation guidance on whether an unrecognized tax benefit must be presented as either a reduction to a deferred tax asset or separately as a liability. The Company adopted this new guidance on January 1, 2014 and the adoption did not have a material impact on the Company's financial condition, results of operations or disclosures.

On May 28, 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. The new standard is effective for the Company on January 1, 2017. Early application is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU No. 2014-09 will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting.

Significant_Accounting_Policie2

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Significant Accounting Policies
Schedule of assets and liabilities measured at fair value on a recurring basis
		Balance as of December 31, 2014
		Total			Level 1			Level 2			Level 3
		(in thousands)
	Assets:
	Cash equivalents	$	82,939		$	82,939		$	—		$	—
	Liabilities:
	Series D redeemable convertible preferred stock warrants	$	—		$	—		$	—		$	—
		Balance as of December 31, 2013
		Total			Level 1			Level 2			Level 3
		(in thousands)
	Assets:
	Cash equivalents	$	3,357		$	3,357		$	—		$	—
	Liabilities:
	Series D redeemable convertible preferred stock warrants	$	126		$	—		$	—		$	126
Schedule of the changes in the Company's Level 3 instruments measured at fair value on a recurring basis
		Series C			Series D
		Warrant			Warrants
		(in thousands)
	Balance as of December 31, 2012	$	—		$	52
	Issuance of warrant		—			107
	Change in fair value of warrant liability		—			(33	)
	Balance as of December 31, 2013		—			126
	Change in fair value of warrant liability		—			695
	Reclassification of warrant liability to additional paid-in capital					(821	)
	Balance as of December 31, 2014	$	—		$	—
Schedule of concentration of revenue
		Year Ended
		December 31,
		2014			2013			2012
	Client A		55	%		69	%		78	%
	Client B		14			16			15
	Client C		13			12			7
Schedule of components of other non-current assets
		December 31,
		2014			2013
		(in thousands)
	Deferred IPO Costs	$	—		$	1,781
	Deferred financing costs		317			634
	Other non-current assets		1,149			911
	Total other non-current assets	$	1,466		$	3,326

Property_and_Equipment_Tables

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Property and Equipment
Schedule of Property and equipment
	Property and equipment consisted of the following as of (in thousands):
		December 31,
		2014			2013
	Internally-developed software	$	7,820		$	5,516
	Computer hardware		3,016			2,082
	Furniture and office equipment		1,104			774
	Leasehold improvements		1,801			1,494
	Total		13,741			9,866
	Accumulated depreciation and amortization		(6,986	)		(4,635	)
	Property and equipment, net	$	6,755		$	5,231

Capitalized_Content_Developmen1

Capitalized Content Development Costs (Tables)	12 Months Ended
	Dec. 31, 2014
Capitalized Content Development Costs
Schedule of capitalized content development costs
	Capitalized content development costs consisted of the following as of (in thousands):
		December 31,
		2014			2013
	Capitalized content development costs	$	16,835		$	11,816
	Capitalized content development costs in process		3,699			1,961
	Accumulated amortization		(7,379	)		(4,873	)
	Capitalized content development costs, net	$	13,155		$	8,904
Schedule of estimated future amortization expense for the capitalized content development costs
	As of December 31, 2014, the estimated future amortization expense for the capitalized content development costs is as follows (in thousands):
	2015	$	3,017
	2016		2,577
	2017		1,983
	2018		1,426
	2019		453
	Total	$	9,456

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies
Schedule of future minimum lease payments, net of aggregate expected sublease payments	As of December 31, 2014, the future minimum lease payments (net of aggregate expected sublease payments of $0.6 million) were as follows (in thousands):
	2015	$	2,772
	2016		2,643
	2017		2,466
	2018		1,809
	2019		821
	Thereafter		494
	Total future minimum lease payments	$	11,005
Schedule of future minimum program payments for intellectual property and other rights	As of December 31, 2014, the future minimum payments to the Company's clients for intellectual property and other rights were as follows (in thousands):
	2015	$	500
	2016		800
	2017		800
	2018		300
	2019		300
	Thereafter		2,700
	Total future minimum payments to clients	$	5,400

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Taxes
Schedule components of loss before income taxes
	The components of loss before income taxes for the years ended December 31 were as follows (in thousands):
		2014			2013			2012
	Domestic	$	(28,999	)	$	(27,953	)	$	(23,113	)
	Total loss before income taxes	$	(28,999	)	$	(27,953	)	$	(23,113	)
Reconciliation of the statutory federal income tax rate to the actual effective income tax rate
		2014			2013			2012
	U.S. statutory federal income tax rate		35	%		35	%		35	%
	Increase (decrease) resulting from:
	U.S. state income taxes, net of federal benefits		5.8			7.3			5.3
	Non-deductible expenses		(2.8	)		(2.1	)		(2.1	)
	Change in valuation allowance		(32.4	)		(39.9	)		(38.1	)
	Other		(5.6	)		(0.3	)		(0.1	)
	Effective tax rate		0	%		0	%		0	%
Components of the Company's deferred tax assets and liabilities	The significant components of the Company's deferred tax assets and liabilities as of December 31 are as follows (in thousands):
		2014			2013
	Deferred tax assets:
	Accrued expenses and other	$	3,556		$	1,501
	Rebate reserve		264			677
	Deferred rent		212			211
	Stock-based compensation		2,782			797
	Net operating loss carryforwards		46,264			37,874
	Valuation allowance		(44,309	)		(34,921	)
	Total deferred tax assets	$	8,769		$	6,139
	Deferred tax liabilities:
	Prepaid expenses and other	$	(1,344	)	$	(462	)
	Capitalized content development costs		(5,439	)		(3,841	)
	Capitalized software development costs		(1,346	)		(1,034	)
	Property and equipment		(640	)		(802	)
	Total deferred tax liabilities	$	(8,769	)	$	(6,139	)
	Net deferred tax assets/liabilities	$	—		$	—

Redeemable_Convertible_Preferr1

Redeemable Convertible Preferred Stock (Tables)	12 Months Ended
	Dec. 31, 2014
Redeemable Convertible Preferred Stock
Schedule of issuances of redeemable convertible preferred stock
	Issue Date	Series		Purchase			Number of			Conversion
				Price per			Shares			Price per
				Share						Share
	Jun-09	Series A		$	1.27			10,033,976		$	1.27
	Feb-10	Series B		$	4.46			5,057,901		$	4.46
	Mar-11	Series C		$	7.34			4,429,601		$	7.34
	Mar-12	Series D		$	7.81			3,339,902		$	7.81
	Jan-13	Series D		$	7.81			639,828		$	7.81
Schedule of activity for the redeemable convertible preferred stock issued and outstanding
		Redeemable Convertible Preferred Stock
		Series A			Series B			Series C			Series D			Total
														Amount
		(in thousands)
	Balance, December 31, 2011	$	12,105		$	21,927		$	32,314		$	—		$	66,346
	Issuance of redeemable convertible preferred stock net of issuance costs		—			—			—			26,021			26,021
	Accretion of issuance costs on redeemable convertible preferred stock		139			141			45			14			339
	Balance, December 31, 2012		12,244			22,068			32,359			26,035			92,706
	Issuance of redeemable convertible preferred stock net of issuance costs		—			—			—			4,994			4,994
	Accretion of issuance costs on redeemable convertible preferred stock		140			142			46			19			347
	Balance, December 31, 2013		12,384			22,210			32,405			31,048			98,047
	Accretion of issuance costs on redeemable convertible preferred stock		36			36			12			5			89
	Conversion of preferred stock into common stock		(12,420	)		(22,246	)		(32,417	)		(31,053	)		(98,136	)
	Balance, December 31, 2014	$	—		$	—		$	—		$	—		$	—

Common_Stock_and_Preferred_Sto1

Common Stock and Preferred Stock Reserved for Future Issuance (Tables)	12 Months Ended
	Dec. 31, 2014
Common Stock and Preferred Stock Reserved for Future Issuance
Schedule of shares of common stock reserved for future issuance
	Outstanding stock options	5,850,211
	Possible future issuance under equity incentive plans	959,830
	Outstanding restricted stock units	992,665
	Total common shares reserved for future issuance	7,802,706

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
Stock options
Schedule of stock-based compensation expense included in the consolidated statements of operations
		Year Ended December 31,
		2014			2013		2012
		(in thousands)
	Servicing and support	$	1,468		$	364	$	180
	Technology and content development		794			159		43
	Program marketing and sales		676			178		162
	General and administrative		4,589			1,725		1,010
	Total stock-based compensation expense	$	7,527		$	2,426	$	1,395
Summary assumptions used for estimating the fair value of the stock options granted
		Year Ended December 31,
		2014		2013		2012
	Risk-free interest rate	1.7% - 2.1%		0.9% - 2.0%		0.8% - 1.1%
	Expected term (years)	5.11 - 6.25		5.54 - 6.31		5.65 - 6.15
	Expected volatility	50% - 55%		55% - 58%		57% - 61%
	Dividend yield	0%		0%		0%
	Weighted-average grant date fair value	$5.71		$4.58		$1.91
Summary of option activity
		Number of			Weighted-Average		Weighted-Average		Aggregate
		Options			Exercise Price		Remaining		Intrinsic
					per Share		Contractual		Value
							Term (in years)		(in thousands)
	Outstanding balance at December 31, 2013		5,883,885		$	3.53		7.45	$	36,884
	Granted		1,319,110			11.23		8.65
	Exercised		(940,642	)		2.43		5.3
	Forfeited		(191,513	)		8.08
	Expired		(220,629	)		0.96
	Outstanding balance at December 31, 2014		5,850,211			5.39		7.33		83,487
	Exercisable at December 31, 2014		3,198,869			3.07		6.31		53,069
	Vested and expected to vest at December 31, 2014		5,649,272			5.27		7.28		81,287
Summary of the number of shares of common stock subject to stock options granted during the period, as well as the associated exercise price per share and the estimated fair value per share of the Company's common stock on the grant date.
	Grant Date	Number of			Exercise Price		Estimated
		Shares			per Share		Grant Date Fair
		Underlying					Value per Share
		Options
		Granted
	January 30, 2014		45,000		$	9.50	$	11.00
	March 6, 2014		1,128,430			11.00		11.00
	March 27, 2014		66,427			13.00		13.00
	April 11, 2014		44,334			12.94		12.94
	July 1, 2014		20,779			16.08		16.08
	August 5, 2014		10,000			13.64		13.64
	October 1, 2014		4,140			15.16		15.16
Restricted Stock Units
Summary of restricted stock unit activity
		Number of			Weighted-
		Restricted			Average Grant
		Stock Units			Date Fair Value
	Outstanding balance at December 31, 2013		—		$	—
	Granted		1,089,286			11.41
	Vested		—			—
	Forfeited		(96,621	)		11.6
	Outstanding balance at December 31, 2014		992,665			11.39

Net_Loss_per_Share_Tables

Net Loss per Share (Tables)	12 Months Ended
	Dec. 31, 2014
Net Loss per Share
Schedule of potential dilutive securities that would have been anti-dilutive due to net loss
		Year Ended December 31,
		2014			2013			2012
	Redeemable convertible preferred stock:
	Series A		—			10,033,976			10,033,976
	Series B		—			5,057,901			5,057,901
	Series C		—			4,429,601			4,429,601
	Series D		—			3,979,730			3,339,902
	Warrants to purchase Series D redeemable convertible preferred stock		—			83,818			12,797
	Stock options		5,850,211			5,883,885			4,766,827
	Restricted stock units		992,665			—			—
Schedule of calculation of basic and diluted net loss per share attributable to common stockholders
		Year Ended December 31,
		2014			2013			2012
	Numerator (in thousands):
	Net loss attributable to common stockholders	$	(29,088	)	$	(28,300	)	$	(23,452	)
	Denominator:
	Weighted-average common shares outstanding, basic and diluted		32,075,107			7,432,055			7,037,090
	Net loss per share attributable to common stockholders, basic and diluted	$	(0.91	)	$	(3.81	)	$	(3.33	)

Quarterly_Financial_Informatio1

Quarterly Financial Information ( Unaudited ) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information ( Unaudited )
Schedule of unaudited quarterly results	Quarterly Financial Information (unaudited, in thousands, except share and per share amounts)
		Three Months Ended
		March 31,			June 30,			September 30,			December 31,
		2014			2014			2014			2014
	Revenue	$	26,332		$	24,744		$	28,407		$	30,756
	Costs and expenses:
	Servicing and support		6,248			7,000			6,598			7,012
	Technology and content development		5,674			5,818			5,726			5,403
	Program marketing and sales		15,241			16,710			16,971			16,296
	General and administrative		5,436			5,708			6,303			5,973
	Total costs and expenses		32,599			35,236			35,598			34,684
	Loss from operations		(6,267	)		(10,492	)		(7,191	)		(3,928	)
	Other income (expense):
	Interest expense		(784	)		(134	)		(176	)		(119	)
	Interest income		1			31			30			30
	Total other income (expense)		(783	)		(103	)		(146	)		(89	)
	Net loss	$	(7,050	)	$	(10,595	)	$	(7,337	)	$	(4,017	)
	Net loss per share:
	Basic and diluted	$	(0.92	)	$	(0.27	)	$	(0.18	)	$	(0.10	)
	Weighted-average shares used in computing net loss per share:
	Basic and diluted		7,698,709			39,304,884			40,269,937			40,577,087
		Three Months Ended
		March 31,			June 30,			September 30,			December 31,
		2013			2013			2013			2013
	Revenue	$	19,134		$	18,691		$	20,499		$	24,803
	Costs and expenses:
	Servicing and support		5,018			5,656			5,842			6,202
	Technology and content development		3,235			4,596			5,113			6,528
	Program marketing and sales		11,770			13,695			15,412			13,226
	General and administrative		2,871			3,654			4,269			4,046
	Total costs and expenses		22,894			27,601			30,636			30,002
	Loss from operations		(3,760	)		(8,910	)		(10,137	)		(5,199	)
	Other income (expense):
	Interest expense		8			5			(1	)		15
	Interest income		6			10			5			5
	Total other income (expense)		14			15			4			20
	Net loss	$	(3,746	)	$	(8,895	)	$	(10,133	)	$	(5,179	)
	Net loss per share:
	Basic and diluted	$	(0.51	)	$	(1.20	)	$	(1.37	)	$	(0.69	)
	Weighted-average shares used in computing net loss per share:
	Basic and diluted		7,386,133			7,398,059			7,415,777			7,528,940

Description_of_the_Business_De

Description of the Business (Details) (USD $)	0 Months Ended
In Millions, except Share data, unless otherwise specified	Apr. 02, 2014	Apr. 02, 2014
Initial Public Offering
Common stock sold and issued in initial public offering (IPO) (in shares)	8,626,377
Issuance price (in dollars per share)		$13
Net proceeds from IPO, after deducting underwriting discounts and commissions and other offering expenses	$100.30
Underwriting discounts and commissions	7.8
Offering expenses	4
Redeemable convertible preferred stock converted into shares of common stock	23,501,208
Preferred stock warrant liability		$0.80

Significant_Accounting_Policie3

Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2014
Minimum
Revenue Recognition and Deferred Revenue
Period to derive revenue under long-term contracts	10 years
Maximum
Revenue Recognition and Deferred Revenue
Period to derive revenue under long-term contracts	15 years

Significant_Accounting_Policie4

Significant Accounting Policies (Details 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assets and liabilities measured at fair value on a recurring basis
Change in fair value of warrant liability		($33)	($22)
Reclassification of warrant liability to additional paid-in capital	821
Series D Warrant
Liabilities:
Series D redeemable convertible preferred stock warrants		126
Assets and liabilities measured at fair value on a recurring basis
Balance at the beginning of the period	126	52
Issuance of warrant		107
Change in fair value of warrant liability	695	-33
Reclassification of warrant liability to additional paid-in capital	-821
Balance at the end of the period		126
Recurring basis | Total
Assets:
Cash equivalents	82,939	3,357
Liabilities:
Series D redeemable convertible preferred stock warrants		126
Assets and liabilities measured at fair value on a recurring basis
Balance at the end of the period		126
Recurring basis | Level 1
Assets:
Cash equivalents	82,939	3,357
Recurring basis | Level 3
Liabilities:
Series D redeemable convertible preferred stock warrants		126
Assets and liabilities measured at fair value on a recurring basis
Balance at the end of the period		$126

Significant_Accounting_Policie5

Significant Accounting Policies (Details 3)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue | Customer concentration risk | Client A
Concentration of Credit Risk
Percentage of concentration of credit risk	55.00%	69.00%	78.00%
Revenue | Customer concentration risk | Client B
Concentration of Credit Risk
Percentage of concentration of credit risk	14.00%	16.00%	15.00%
Revenue | Customer concentration risk | Client C
Concentration of Credit Risk
Percentage of concentration of credit risk	13.00%	12.00%	7.00%
Accounts receivable | Credit concentration risk
Concentration of Credit Risk
Percentage of concentration of credit risk	35.00%	51.00%
Number of additional clients who accounted for more than 10%	2	1

Significant_Accounting_Policie6

Significant Accounting Policies (Details 4) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property and equipment
Costs incurred during the period	$5,403,000	$5,726,000	$5,818,000	$5,674,000	$6,528,000	$5,113,000	$4,596,000	$3,235,000	$22,621,000	$19,472,000	$8,299,000
Capitalized Content Development Costs
Useful life of capitalized content development costs									5 years
Impairment of Long-Lived Assets
Impairments of long-lived assets					800,000				0		0
Other Non-Current Assets
Deferred IPO Costs					1,781,000					1,781,000
Deferred financing costs	317,000				634,000				317,000	634,000
Other non-current assets	1,149,000				911,000				1,149,000	911,000
Other Assets, Noncurrent, Total	1,466,000				3,326,000				1,466,000	3,326,000
Rebate Reserve
Period of teaching in designated low-income school to get rebate									5 years
Period start with in teaching in designated low-income school to get rebate									6 years
Computer hardware | Minimum
Property and equipment
Useful life									3 years
Computer hardware | Maximum
Property and equipment
Useful life									5 years
Furniture and office equipment | Minimum
Property and equipment
Useful life									5 years
Furniture and office equipment | Maximum
Property and equipment
Useful life									7 years
Leasehold improvements | Minimum
Property and equipment
Useful life									4 years
Leasehold improvements | Maximum
Property and equipment
Useful life									10 years
Internally-developed software
Property and equipment
Useful life									3 years
Costs incurred during the period									2,300,000	1,300,000	1,100,000
Related amortization expense									1,400,000	1,500,000	900,000
Net book value	$3,300,000				$2,400,000				$3,300,000	$2,400,000

Property_and_Equipment_Details

Property and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property and equipment
Property and equipment, gross	$13,741,000	$9,866,000
Accumulated depreciation and amortization	-6,986,000	-4,635,000
Property and equipment, net	6,755,000	5,231,000
Depreciation expense	2,400,000	2,100,000	1,300,000
Internally-developed software
Property and equipment
Property and equipment, gross	7,820,000	5,516,000
Computer hardware
Property and equipment
Property and equipment, gross	3,016,000	2,082,000
Furniture and office equipment
Property and equipment
Property and equipment, gross	1,104,000	774,000
Leasehold improvements
Property and equipment
Property and equipment, gross	$1,801,000	$1,494,000

Capitalized_Content_Developmen2

Capitalized Content Development Costs (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Capitalized Content Development Costs
Capitalized content development costs	$16,835,000	$11,816,000
Capitalized content development costs in process	3,699,000	1,961,000
Accumulated amortization	-7,379,000	-4,873,000
Capitalized content development costs, net	13,155,000	8,904,000
Amortization expense related to capitalized content development costs	3,200,000	2,200,000	1,500,000
Estimated future amortization expense for the capitalized content development costs
2015	3,017,000
2016	2,577,000
2017	1,983,000
2018	1,426,000
2019	453,000
Total	$9,456,000

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	0 Months Ended		12 Months Ended
	Feb. 18, 2014	Jan. 21, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 05, 2012
Line of Credit
Aggregate borrowing base				$37,000,000		$10,000,000
Amount borrowed		5,000,000	5,000,000
Borrowings repaid	5,000,000		5,000,000
Amount outstanding			0
Aggregate expected sublease payments			600,000
Future minimum lease payments, net of aggregate expected sublease payments
2015			2,772,000
2016			2,643,000
2017			2,466,000
2018			1,809,000
2019			821,000
Thereafter			494,000
Total future minimum lease payments			11,005,000
Total net rent expense			500,000	500,000
Rent expense net of sublease income			2,600,000	2,100,000	1,700,000
Sublease income			300,000	300,000	300,000
Future minimum program payments for intellectual property and other rights
2015			500,000
2016			800,000
2017			800,000
2018			300,000
2019			300,000
Thereafter			2,700,000
Total future minimum payments to clients			$5,400,000
Base rate
Line of Credit
Variable interest rate basis			Base rate
Applicable margin (as a percent)			1.50%
Federal fund rate
Line of Credit
Variable interest rate basis			Federal fund rate
Applicable margin (as a percent)			1.00%
30 days LIBOR
Line of Credit
Variable interest rate basis			30 days LIBOR
Applicable margin (as a percent)			1.00%
LIBOR
Line of Credit
Variable interest rate basis			One, two and three months LIBOR
Applicable margin (as a percent)			2.50%
Minimum
Line of Credit
Convenants ratio			1.1

Income_Taxes_Details

Income Taxes (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Components of loss before income taxes
Domestic	($28,999)	($27,953)	($23,113)
Loss before income taxes	-28,999	-27,953	-23,113
Reconciliation between statutory federal income tax rate and the effective tax rate
U.S. statutory federal income tax rate (as a percent)	35.00%	35.00%	35.00%
U.S. state income taxes, net of federal benefits (as a percent)	5.80%	7.30%	5.30%
Non-deductible expenses (as a percent)	-2.80%	-2.10%	-2.10%
Change in valuation allowance (as a percent)	-32.40%	-39.90%	-38.10%
Other (as a percent)	-5.60%	-0.30%	-0.10%
Effective tax rate (as a percent)	0.00%	0.00%	0.00%
Deferred tax assets:
Accrued expenses and other	3,556	1,501
Rebate reserve	264	677
Deferred rent	212	211
Stock-based compensation	2,782	797
Net operating loss carryforwards	46,264	37,874
Valuation allowance	-44,309	-34,921
Total deferred tax assets	8,769	6,139
Deferred tax liabilities:
Prepaid expenses and other	-1,344	-462
Capitalized content development costs	-5,439	-3,841
Capitalized software development costs	-1,346	-1,034
Property and equipment	-640	-802
Total deferred tax liabilities	($8,769)	($6,139)

Income_Taxes_Details_2

Income Taxes (Details 2) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	item
Income Taxes
Federal net operating loss carryforwards	$123.40	$86
Increase in valuation allowance	9.4
Effective tax rate (as a percent)	0.00%	0.00%	0.00%
Accrued interest or penalties related to uncertain tax positions	$0	$0
Income tax returns currently under examination	0

Redeemable_Convertible_Preferr2

Redeemable Convertible Preferred Stock (Details) (USD $)	0 Months Ended		3 Months Ended	12 Months Ended			1 Months Ended
	Apr. 02, 2014	Apr. 03, 2012	Apr. 02, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2009	Feb. 28, 2010	Mar. 31, 2011	Jan. 31, 2014	Mar. 31, 2012
				item
Issuances of redeemable convertible preferred stock
Purchase Price per Share (in dollars per share)	$13		$13
Number of Shares				0	0
Summary of activity for the Preferred Stock issued and outstanding
Balance at the beginning of the period			$98,047,000	$98,047,000	$92,706,000	$66,346,000				$98,047,000
Issuance of redeemable convertible preferred stock net of issuance costs					4,994,000	26,021,000
Accretion of issuance costs on redeemable convertible preferred stock				89,000	347,000	339,000
Conversion of preferred stock into common stock				-98,136,000
Balance at the end of the period					98,047,000	92,706,000
Redemption Rights
Period within which the outstanding preferred stock is to be redeemed on receipt of written request		90 days
Minimum percentage of outstanding preferred shareholders required to file a written request		75.00%
Redeemable convertible preferred stock converted into shares of common stock	23,501,208
Redeemable convertible preferred stock, shares authorized				0	0
Redeemable convertible preferred stock, shares issued				0	0
Redeemable convertible preferred stock, shares outstanding				0	0
Conversion Rights
Redeemable convertible preferred stock, conversion ratio				1
Aggregate cash proceeds	100,300,000
Number of votes per share				1
Dividends declared during the period			$0
First Condition
Conversion Rights
Deemed total market value of the company				330,000,000
First Condition | Minimum
Conversion Rights
Aggregate cash proceeds				50,000,000
Series A
Issuances of redeemable convertible preferred stock
Purchase Price per Share (in dollars per share)							$1.27
Number of Shares				0	10,033,976		10,033,976
Conversion Price per Share (in dollars per share)							$1.27
Summary of activity for the Preferred Stock issued and outstanding
Balance at the beginning of the period			12,384,000	12,384,000	12,244,000	12,105,000				12,384,000
Accretion of issuance costs on redeemable convertible preferred stock				36,000	140,000	139,000
Conversion of preferred stock into common stock				-12,420,000
Balance at the end of the period					12,384,000	12,244,000
Redemption Rights
Redeemable convertible preferred stock, shares authorized				0	10,033,976
Redeemable convertible preferred stock, shares issued				0	10,033,976		10,033,976
Redeemable convertible preferred stock, shares outstanding				0	10,033,976
Redemption value					12,700,000
Conversion Rights
Dividends payable per share					$0.10
Series A | Second Condition
Conversion Rights
Minimum percentage of preferred stock holders with voting rights who are required to send a written request or vote in favor of redemption				66.67%
Series B
Issuances of redeemable convertible preferred stock
Purchase Price per Share (in dollars per share)								$4.46
Number of Shares				0	5,057,901			5,057,901
Conversion Price per Share (in dollars per share)								$4.46
Summary of activity for the Preferred Stock issued and outstanding
Balance at the beginning of the period			22,210,000	22,210,000	22,068,000	21,927,000				22,210,000
Accretion of issuance costs on redeemable convertible preferred stock				36,000	142,000	141,000
Conversion of preferred stock into common stock				-22,246,000
Balance at the end of the period					22,210,000	22,068,000
Redemption Rights
Redeemable convertible preferred stock, shares authorized				0	5,057,901
Redeemable convertible preferred stock, shares issued				0	5,057,901			5,057,901
Redeemable convertible preferred stock, shares outstanding				0	5,057,901
Redemption value					22,600,000
Conversion Rights
Dividends payable per share					$0.36
Series C
Issuances of redeemable convertible preferred stock
Purchase Price per Share (in dollars per share)									$7.34
Number of Shares				0	4,429,601				4,429,601
Conversion Price per Share (in dollars per share)									$7.34
Summary of activity for the Preferred Stock issued and outstanding
Balance at the beginning of the period			32,405,000	32,405,000	32,359,000	32,314,000				32,405,000
Accretion of issuance costs on redeemable convertible preferred stock				12,000	46,000	45,000
Conversion of preferred stock into common stock				-32,417,000
Balance at the end of the period					32,405,000	32,359,000
Redemption Rights
Redeemable convertible preferred stock, shares authorized				0	4,429,601
Redeemable convertible preferred stock, shares issued				0	4,429,601				4,429,601
Redeemable convertible preferred stock, shares outstanding				0	4,429,601
Redemption value					32,500,000
Conversion Rights
Dividends payable per share					$0.59
Series C | Second Condition
Conversion Rights
Minimum percentage of preferred stock holders with voting rights who are required to send a written request or vote in favor of redemption				60.00%
Series D
Issuances of redeemable convertible preferred stock
Purchase Price per Share (in dollars per share)										$7.81	$7.81
Number of Shares				0	3,979,730					639,828	3,339,902
Conversion Price per Share (in dollars per share)										$7.81	$7.81
Summary of activity for the Preferred Stock issued and outstanding
Balance at the beginning of the period			31,048,000	31,048,000	26,035,000					31,048,000
Issuance of redeemable convertible preferred stock net of issuance costs					4,994,000	26,021,000
Accretion of issuance costs on redeemable convertible preferred stock				5,000	19,000	14,000
Conversion of preferred stock into common stock				-31,053,000
Balance at the end of the period					31,048,000	26,035,000
Redemption Rights
Redeemable convertible preferred stock, shares authorized				0	4,069,352
Redeemable convertible preferred stock, shares issued				0	3,979,730					639,828	3,339,902
Redeemable convertible preferred stock, shares outstanding				0	3,979,730
Redemption value					$31,100,000
Conversion Rights
Dividends payable per share					$0.63
Series D | Second Condition
Conversion Rights
Minimum percentage of preferred stock holders with voting rights who are required to send a written request or vote in favor of redemption				60.00%

Common_Stock_and_Preferred_Sto2

Common Stock and Preferred Stock Reserved for Future Issuance (Details)	Dec. 31, 2014	Apr. 02, 2014	Dec. 31, 2013
Common Stock and Preferred Stock Reserved for Future Issuance
Authorized shares of capital stock	205,000,000
Authorized shares of common stock	200,000,000	200,000,000	60,000,000
Authorized shares of preferred stock	5,000,000	5,000,000	0
Shares of common stock reserved for future issuance
Outstanding stock options	5,850,211
Possible future issuance under equity incentive plans	959,830
Outstanding restricted stock units	992,665
Total common shares reserved for future issuance	7,802,706

Warrants_Details

Warrants (Details) (USD $)	0 Months Ended			12 Months Ended
In Thousands, except Share data, unless otherwise specified	22-May-14	22-May-14	Apr. 02, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 30, 2012
Warrants
Amount of warrants liability reclassified to additional paid in capital on conversion of warrants to purchase Series D redeemable convertible preferred stock			$821
Reductions of interest expense					33	22
Interest expense on fair value adjustment of the warrants				695
Shares of common stock to be purchased upon receipt of notice of exercise from holder of warrants	83,818	83,818
Number of trading days considered in volume weighted average price of common stock		10 days
Issuance of shares of common stock upon receipt of notice of exercise from holder of warrants	32,709
Warrant issued to purchase Series D redeemable convertible preferred stock expiring in 2022
Warrants
Number of shares of preferred stock that may be purchased by warrant							12,797
Exercise price of warrant (in dollars per share)							$7.81
Fair value of warrant					19		74
Warrant issued to purchase Series D redeemable convertible preferred stock expiring in 2023
Warrants
Number of shares of preferred stock that may be purchased by warrant					71,021
Exercise price of warrant (in dollars per share)					$7.81
Fair value of warrant					$107

StockBased_Compensation_Detail

Stock-Based Compensation (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 01, 2015	Jan. 30, 2014
	item
Stock-Based Compensation
Number of share-based employee compensation plans	2
Stock-based compensation expense included in the unaudited condensed consolidated statements of operations
Common stock reserved for issuance	7,802,706
Stock-based compensation expense	$7,527	$2,426	$1,395
Servicing and support
Stock-based compensation expense included in the unaudited condensed consolidated statements of operations
Stock-based compensation expense	1,468	364	180
Technology and content development
Stock-based compensation expense included in the unaudited condensed consolidated statements of operations
Stock-based compensation expense	794	159	43
Program marketing and sales
Stock-based compensation expense included in the unaudited condensed consolidated statements of operations
Stock-based compensation expense	676	178	162
General and administrative
Stock-based compensation expense included in the unaudited condensed consolidated statements of operations
Stock-based compensation expense	$4,589	$1,725	$1,010
Restricted Stock Units
Stock-based compensation expense included in the unaudited condensed consolidated statements of operations
Restricted stock units outstanding	992,665
2014 Equity Incentive Plan
Stock-based compensation expense included in the unaudited condensed consolidated statements of operations
Shares authorized under the plan	2,800,000
Number of shares that may be added to the 2014 Plan	5,943,348
Period of annual automatic increase in the number of shares authorized	10 years
Percentage applied on total number of shares of common stock outstanding on previous calendar year for automatic inclusion in the plan	5.00%
Common stock reserved for issuance	959,830
Option to purchase common stock, outstanding	1,197,741
Weighted average exercise price	$11.28
2014 Equity Incentive Plan | Maximum
Stock-based compensation expense included in the unaudited condensed consolidated statements of operations
Number of options or stock awards available for grant under the Plan	5,943,348
2014 Equity Incentive Plan | Restricted Stock Units
Stock-based compensation expense included in the unaudited condensed consolidated statements of operations
Restricted stock units outstanding	992,665
2014 Equity Incentive Plan | Subsequent event
Stock-based compensation expense included in the unaudited condensed consolidated statements of operations
Common stock reserved for issuance				2,036,503
2008 Equity Incentive Plan
Stock-based compensation expense included in the unaudited condensed consolidated statements of operations
Number of options or stock awards available for grant under the Plan					0
Option to purchase common stock, outstanding	4,652,470
Weighted average exercise price	$3.87

StockBased_Compensation_Detail1

Stock-Based Compensation (Details 2) (USD $)	0 Months Ended							12 Months Ended
	Oct. 01, 2014	Aug. 05, 2014	Jul. 01, 2014	Apr. 11, 2014	Mar. 27, 2014	Mar. 06, 2014	Jan. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Additional disclosures
Compensation cost related to the nonvested awards not yet recognized								$9,600,000
Weighted average period for recognition of compensation cost								2 years 3 months 18 days
Summary of restricted stock unit activity
Total unrecognized compensation cost related to unvested RSUs								7,500,000
Unrecognized compensation cost period expected to be realized								3 years
Stock options
Stock-Based Compensation
Vesting period								4 years
Expiration period								10 years
Fair value assumptions and methodology
Dividend yield (as a percent)								0.00%	0.00%	0.00%
Weighted average grant date fair value (in dollars per share)	$15.16	$13.64	$16.08	$12.94	$13	$11	$11	$5.71	$4.58	$1.91
Number of Options
Outstanding balance at the beginning of the period (in shares)								5,883,885
Granted (in shares)	4,140	10,000	20,779	44,334	66,427	1,128,430	45,000	1,319,110
Exercised (in shares)								-940,642
Forfeited (in shares)								-191,513
Expired (in shares)								-220,629
Outstanding balance at the end of the period (in shares)								5,850,211	5,883,885
Exercisable at the end of the period (in shares)								3,198,869
Vested and expected to vest at the end of the period (in shares)								5,649,272
Weighted Average Exercise Price per Share
Outstanding balance at the beginning of the period (in dollars per share)								$3.53
Granted (in dollars per share)	$15.16	$13.64	$16.08	$12.94	$13	$11	$9.50	$11.23
Exercised (in dollars per share)								$2.43
Forfeited (in dollars per share)								$8.08
Expired (in dollars per share)								$0.96
Outstanding balance at the end of the period (in dollars per share)								$5.39	$3.53
Exercisable at the end of the period (in dollars per share)								$3.07
Vested and expected to vest at the end of the period (in dollars per share)								$5.27
Weighted Average Remaining Contractual Term
Outstanding balance at the beginning of the period								7 years 3 months 29 days	7 years 5 months 12 days
Granted								8 years 7 months 24 days
Exercised								5 years 3 months 18 days
Outstanding balance at the end of the period								7 years 3 months 29 days	7 years 5 months 12 days
Exercisable at the end of the period								6 years 3 months 22 days
Vested and expected to vest at the end of the period								7 years 3 months 11 days
Aggregate Intrinsic Value
Outstanding balance at the end of the period								83,487,000	36,884,000
Exercisable at the end of the period								53,069,000
Vested and expected to vest at the end of the period								81,287,000
Additional disclosures
Aggregate intrinsic value of employee options exercised								$16,200,000	$1,800,000	$1,600,000
Summary of shares of common stock granted during the period
Number of Shares Underlying Options Granted	4,140	10,000	20,779	44,334	66,427	1,128,430	45,000	1,319,110
Exercise Price per Share	$15.16	$13.64	$16.08	$12.94	$13	$11	$9.50	$11.23
Estimated Grant Date Fair Value per Share	$15.16	$13.64	$16.08	$12.94	$13	$11	$11	$5.71	$4.58	$1.91
Stock options | Minimum
Fair value assumptions and methodology
Risk-free interest rate (as a percent)								1.70%	0.90%	0.80%
Expected Term in (Years)								5 years 1 month 10 days	5 years 6 months 15 days	5 years 7 months 24 days
Expected Volatility (as a percent)								50.00%	55.00%	57.00%
Stock options | Maximum
Fair value assumptions and methodology
Risk-free interest rate (as a percent)								2.10%	2.00%	1.10%
Expected Term in (Years)								6 years 3 months	6 years 3 months 22 days	6 years 1 month 24 days
Expected Volatility (as a percent)								55.00%	58.00%	61.00%
Restricted Stock Units
Stock-Based Compensation
Vesting period								4 years
Summary of restricted stock unit activity
Granted (in shares)								1,089,286
Forfeited (in shares)								-96,621
Outstanding balance at the end of the period (in shares)								992,665
Weighted-Average Grant-Date Fair value
Granted (in dollars per share)								$11.41
Forfeited (in dollars per share)								$11.60
Outstanding at the end of the period (in dollars per share)								$11.39

Net_Loss_per_Share_Details

Net Loss per Share (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restricted Stock Units
Potential dilutive securities that would have been anti-dilutive
Potential dilutive securities that would have been anti-dilutive due to net loss (in shares)	992,665
Series A
Potential dilutive securities that would have been anti-dilutive
Potential dilutive securities that would have been anti-dilutive due to net loss (in shares)		10,033,976	10,033,976
Series B
Potential dilutive securities that would have been anti-dilutive
Potential dilutive securities that would have been anti-dilutive due to net loss (in shares)		5,057,901	5,057,901
Series C
Potential dilutive securities that would have been anti-dilutive
Potential dilutive securities that would have been anti-dilutive due to net loss (in shares)		4,429,601	4,429,601
Series D
Potential dilutive securities that would have been anti-dilutive
Potential dilutive securities that would have been anti-dilutive due to net loss (in shares)		3,979,730	3,339,902
Warrants to purchase Series D redeemable convertible preferred stock
Potential dilutive securities that would have been anti-dilutive
Potential dilutive securities that would have been anti-dilutive due to net loss (in shares)		83,818	12,797
Stock options
Potential dilutive securities that would have been anti-dilutive
Potential dilutive securities that would have been anti-dilutive due to net loss (in shares)	5,850,211	5,883,885	4,766,827

Net_Loss_per_Share_Details_2

Net Loss per Share (Details 2) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Numerator
Net loss attributable to common stockholders									($29,088)	($28,300)	($23,452)
Denominator:
Weighted-average common shares outstanding, basic and diluted (in shares)	40,577,087	40,269,937	39,304,884	7,698,709	7,528,940	7,415,777	7,398,059	7,386,133	32,075,107	7,432,055	7,037,090
Basic and diluted (in dollars per share)	($0.10)	($0.18)	($0.27)	($0.92)	($0.69)	($1.37)	($1.20)	($0.51)	($0.91)	($3.81)	($3.33)

Segment_and_Geographic_Informa1

Segment and Geographic Information (Details)	12 Months Ended
	Dec. 31, 2014
	segment
Segment and Geographic Information
Number of reportable segments	1

Retirement_Plan_Details

Retirement Plan (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Retirement Plan
Eligible Employees to contribute	100.00%
Employee contribution	33.00%
Maximum matching contributions as a percentage of eligible compensation	6.00%
Contributions made by Company	$0.60	$0.40	$0.30

Related_Party_Transactions_Det

Related Party Transactions (Details) (USD $)	12 Months Ended
In Millions, except Share data in Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Related Party Transactions
Rental income from related entity	$0.30	$0.20	$0.20
Executive Officer
Related Party Transactions
Expenses incurred related to the services received from related party	1.6	0.8	0.4
Notes receivable			$0.30
Interest rate (as percent)			2.18%
Notes secured through stock options held by related party			869

Quarterly_Financial_Informatio2

Quarterly Financial Information ( Unaudited ) (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue
Revenue	$30,756	$28,407	$24,744	$26,332	$24,803	$20,499	$18,691	$19,134	$110,239	$83,127	$55,879
Costs and expenses:
Servicing and support	7,012	6,598	7,000	6,248	6,202	5,842	5,656	5,018	26,858	22,718	14,926
Technology and content development	5,403	5,726	5,818	5,674	6,528	5,113	4,596	3,235	22,621	19,472	8,299
Program marketing and sales	16,296	16,971	16,710	15,241	13,226	15,412	13,695	11,770	65,218	54,103	45,390
General and administrative	5,973	6,303	5,708	5,436	4,046	4,269	3,654	2,871	23,420	14,840	10,342
Total costs and expenses	34,684	35,598	35,236	32,599	30,002	30,636	27,601	22,894	138,117	111,133	78,957
Loss from operations	-3,928	-7,191	-10,492	-6,267	-5,199	-10,137	-8,910	-3,760	-27,878	-28,006	-23,078
Other income (expense):
Interest expense	-119	-176	-134	-784	15	-1	5	8	-1,213	27	-73
Interest income	30	30	31	1	5	5	10	6	92	26	38
Total other income (expense)	-89	-146	-103	-783	20	4	15	14	-1,121	53	-35
Net loss	($4,017)	($7,337)	($10,595)	($7,050)	($5,179)	($10,133)	($8,895)	($3,746)	($28,999)	($27,953)	($23,113)
Net Loss per Share
Basic and diluted (in dollars per share)	($0.10)	($0.18)	($0.27)	($0.92)	($0.69)	($1.37)	($1.20)	($0.51)	($0.91)	($3.81)	($3.33)
Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract]
Basic and diluted (in shares)	40,577,087	40,269,937	39,304,884	7,698,709	7,528,940	7,415,777	7,398,059	7,386,133	32,075,107	7,432,055	7,037,090

SCHEDULE_IIVALUATION_AND_QUALI1

SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for Doubtful Accounts
Changes in valuation and qualifying accounts
Balance at Beginning of Period	$12
Additions Charged to Expense/Against Revenue		12
Deductions	-12
Balance at End of Period		12
Income tax valuation allowance
Changes in valuation and qualifying accounts
Balance at Beginning of Period	34,921	23,864	15,072
Additions Charged to Expense/Against Revenue	9,388	11,057	8,792
Balance at End of Period	$44,309	$34,921	$23,864