American Public Education (APEI) 10-K 27 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Feb. 23, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Entity Registrant Name	AMERICAN PUBLIC EDUCATION INC
Entity Central Index Key	1,201,792
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		16,391,309
Trading Symbol	APEI
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 260.9

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents (Note 2)	$ 179,205	$ 146,351
Accounts receivable, net of allowance of $8,077 in 2016 and $6,276 in 2017.	7,136	6,949
Prepaid expenses	4,792	5,327
Total current assets	191,133	158,627
Property and equipment, net	92,374	97,687
Assets held for sale	0	2,100
Investments	12,481	14,611
Goodwill	33,899	33,899
Other assets, net	9,151	8,696
Total assets	339,038	315,620
Current liabilities:
Accounts payable	8,844	6,853
Accrued liabilities	13,423	14,124
Deferred revenue	19,374	20,639
Income tax payable	1,710	559
Total current liabilities	43,351	42,175
Deferred income taxes	6,281	8,775
Total liabilities	49,632	50,950
Commitments and contingencies (Notes 8 and 12)
Stockholders’ equity:
Preferred Stock, $.01 par value; authorized shares - 10,000; no shares issued or outstanding	0	0
Common Stock, $.01 par value; authorized shares - 100,000; 16,109 issued and outstanding in 2016; 16,268 issued and outstanding in 2017	163	161
Additional paid-in capital	180,674	177,061
Retained earnings	108,569	87,448
Total stockholders’ equity	289,406	264,670
Total liabilities and stockholders’ equity	$ 339,038	$ 315,620

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Accounts receivable, allowance	$ 6,276	$ 8,077
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, Authorized shares (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, Authorized shares (in shares)	100,000,000	100,000,000
Common stock, issued (in shares)	16,268,000	16,109,000
Common stock, outstanding (in shares)	16,268,000	16,109,000

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Revenue	$ 299,248,000	$ 313,139,000	$ 327,910,000
Costs and expenses:
Instructional costs and services	116,161,000	117,013,000	118,848,000
Selling and promotional	58,335,000	59,095,000	62,397,000
General and administrative	69,024,000	68,666,000	73,047,000
Loss on disposals of long-lived assets	2,093,000	5,970,000	817,000
Impairment of goodwill	0	4,735,000	0
Depreciation and amortization	18,776,000	19,384,000	20,520,000
Total costs and expenses	264,389,000	274,863,000	275,629,000
Income from operations before interest income and income taxes	34,859,000	38,276,000	52,281,000
Interest income, net	185,000	116,000	115,000
Income from operations before income taxes	35,044,000	38,392,000	52,396,000
Income tax expense	11,493,000	14,940,000	20,072,000
Equity investment income (loss)	(2,430,000)	703,000	90,000
Net income	$ 21,121,000	$ 24,155,000	$ 32,414,000
Net income per common share:
Basic (in dollars per share)	$ 1.30	$ 1.50	$ 1.94
Diluted (in dollars per share)	$ 1.29	$ 1.49	$ 1.93
Weighted average number of shares outstanding:
Basic (in shares)	16,236	16,068	16,676
Diluted (in shares)	16,380	16,214	16,798

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Repurchased Stock	Additional Paid-In Capital	Retained Earnings
Beginning balance (in shares) at Dec. 31, 2014		17,151,868	0
Beginning balance at Dec. 31, 2014	$ 234,218	$ 172	$ 0	$ 169,654	$ 64,392
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued for cash (in shares)		213,921
Stock issued for cash	55	$ 1		54
Stock issued for director compensation (in shares)		2,248
Stock issued for director compensation	66			66
Repurchased shares of common and restricted stock from stockholders (in shares)		(56,272)	(1,322,846)
Repurchased shares of common and restricted stock from stockholders	(35,310)		$ (33,526)	(1,784)
Stock-based compensation	$ 6,229			6,229
Repurchased and retired shares of common stock (in shares)	1,322,846	1,322,952	1,322,846
Repurchased and retired shares of common stock		$ (13)	$ 33,526		(33,513)
Excess tax benefit (expense) from stock based compensation	$ (519)			(519)
Net income	32,414				32,414
Ending balance at Dec. 31, 2015	237,153	$ 160	$ 0	173,700	63,293
Ending balance (in shares) at Dec. 31, 2015		15,988,813	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued for cash (in shares)		167,270
Stock issued for cash	119	$ 1		118
Stock issued for director compensation (in shares)		2,322
Stock issued for director compensation	47			47
Repurchased shares of common and restricted stock from stockholders (in shares)		(49,512)
Repurchased shares of common and restricted stock from stockholders	(848)			(848)
Stock-based compensation	$ 5,164			5,164
Repurchased and retired shares of common stock (in shares)	0
Excess tax benefit (expense) from stock based compensation	$ (1,120)			(1,120)
Net income	24,155				24,155
Ending balance at Dec. 31, 2016	264,670	$ 161	$ 0	177,061	87,448
Ending balance (in shares) at Dec. 31, 2016		16,108,893	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued for cash (in shares)		223,800
Stock issued for cash	98	$ 2		96
Stock issued for director compensation (in shares)		3,186
Stock issued for director compensation	72			72
Repurchased shares of common and restricted stock from stockholders (in shares)		(68,065)
Repurchased shares of common and restricted stock from stockholders	(1,587)			(1,587)
Stock-based compensation	$ 5,032			5,032
Repurchased and retired shares of common stock (in shares)	0
Net income	$ 21,121				21,121
Ending balance at Dec. 31, 2017	$ 289,406	$ 163	$ 0	$ 180,674	$ 108,569
Ending balance (in shares) at Dec. 31, 2017		16,267,814	0

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating activities
Net income	$ 21,121,000	$ 24,155,000	$ 32,414,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	18,776,000	19,384,000	20,520,000
Stock-based compensation	6,246,000	5,211,000	5,912,000
Equity investment loss/(income)	2,430,000	(703,000)	(90,000)
Deferred income taxes	(2,494,000)	(455,000)	(160,000)
Loss on disposal of long-lived assets	2,093,000	5,970,000	817,000
Impairment of goodwill	0	4,735,000	0
Other	353,000	329,000	(133,000)
Changes in operating assets and liabilities:
Accounts receivable, net of allowance for bad debt	(187,000)	968,000	(1,787,000)
Prepaid expenses and other assets	(82,000)	997,000	64,000
Income tax receivable	0	0	2,029,000
Accounts payable	1,991,000	589,000	(4,765,000)
Accrued liabilities	(2,195,000)	(424,000)	56,000
Income tax payable	1,151,000	(123,000)	682,000
Deferred revenue and student deposits	(1,265,000)	(4,619,000)	1,453,000
Net cash provided by operating activities	47,938,000	56,014,000	57,012,000
Investing activities
Capital expenditures	(10,855,000)	(13,826,000)	(26,002,000)
Capitalized program development costs and other assets	(3,933,000)	(2,573,000)	(1,265,000)
Proceeds from the sale of real property	1,493,000	844,000	0
Equity investments	(300,000)	(950,000)	(3,871,000)
Dividend received from equity investment	0	2,957,000	0
Net cash used in investing activities	(13,595,000)	(13,548,000)	(31,138,000)
Financing activities
Cash paid for repurchase of common/restricted stock	(1,587,000)	(847,000)	(35,310,000)
Cash received from issuance of common stock	98,000	118,000	55,000
Excess tax expense from stock-based compensation	0	(1,120,000)	(519,000)
Net cash used in financing activities	(1,489,000)	(1,849,000)	(35,774,000)
Net increase (decrease) in cash and cash equivalents	32,854,000	40,617,000	(9,900,000)
Cash and cash equivalents at beginning of period	146,351,000	105,734,000	115,634,000
Cash and cash equivalents at end of period	179,205,000	146,351,000	105,734,000
Supplemental disclosures of cash flow information
Income taxes paid	$ 12,836,000	$ 16,637,000	$ 18,037,000

Nature of Business

Nature of Business	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business	Nature of Business American Public Education, Inc., or APEI, which together with its subsidiaries is referred to as the “Company,” is a provider of online and campus-based postsecondary education to approximately 85,500 students through two subsidiary institutions: • American Public University System, Inc., or APUS, provides online postsecondary education directed primarily at the needs of the military, military-affiliated and public safety communities through American Military University, or AMU, and American Public University, or APU. APUS is regionally accredited by the Higher Learning Commission. • National Education Seminars, Inc., which is referred to herein as Hondros College of Nursing, or HCN, provides nursing education to students at five campuses in Ohio as well as online to serve the needs of the nursing and healthcare communities. HCN is nationally accredited by the Accrediting Council of Independent Colleges and Schools, or ACICS, and the online Registered Nurse to Bachelor of Science in Nursing program, or RN-to-BSN Program, is accredited by the Commission on Collegiate Nursing Education. In June 2016, HCN was notified that its Diploma in Practical Nursing and Associate Degree in Nursing programs, or the PN and ADN Programs, were granted pre-accreditation candidacy status by the National League for Nursing Commission for Nursing Education Accreditation. The Company’s institutions are licensed or otherwise authorized, or are in the process of obtaining such licenses or authorizations, to offer postsecondary education programs by state authorities to the extent the institutions believe such licenses or authorizations are required, and are certified by the United States Department of Education, or ED, to participate in student financial aid programs authorized under Title IV of the Higher Education Act of 1965, as amended, or Title IV programs. The Company’s operations are organized into two reportable segments: • American Public Education Segment, or APEI Segment. This segment reflects the operational activities at APUS, other corporate activities, and minority investments. • Hondros College of Nursing Segment, or HCN Segment. This segment reflects the operational activities of HCN.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies A summary of the Company’s significant accounting policies follows: Basis of presentation and accounting. The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United Sates, or GAAP. Certain prior year amounts have been reclassified for comparative purposes to conform with the 2017 presentation. Principles of consolidation. The accompanying consolidated financial statements include accounts of APEI and its wholly owned subsidiaries. All material intercompany transactions and balances have been eliminated in consolidation. Use of estimates. In preparing financial statements in conformity with GAAP, the Company is required to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses during the reporting period. The Company evaluates these estimates and judgments on an ongoing basis and bases its estimates on experience, current and expected future conditions and various other assumptions that the Company believes are reasonable under the circumstances. Actual results could differ from those estimates. Cash and cash equivalents. The Company considers all short-term highly liquid investments with maturities of three months or less when purchased to be cash equivalents. Cash and cash equivalents consist of demand deposits with financial institutions, money market funds invested in securities backed by the U.S. government and U.S. Treasury bills. Cash and cash equivalents are Level 1 assets in the fair value reporting hierarchy. Restricted cash. Cash and cash equivalents includes funds held for students for unbilled educational services that were received from Title IV programs. As a trustee of these Title IV program funds, the Company is required to maintain and restrict these funds pursuant to the terms of the program participation agreement with the U.S. Department of Education. Restricted cash on the Company’s Consolidated Balance Sheets as of December 31, 2016 and 2017 was $1.6 million and $2.3 million , respectively. Changes in restricted cash that represent funds held for students as described above are included in cash flows from operating activities on the Consolidated Statements of Cash Flows because these restricted funds are a core activity of operations. Accounts receivable. Course tuition is recorded as accounts receivable and deferred revenue at the time students begin a course or term. Students may remit tuition payments at any time or they may elect various other payment options with payment terms extending beyond the start of the course or term. These other payment options include payments by sponsors, financial aid, alternative loans, or tuition assistance programs that remit payments directly to the subsidiary. When a student remits payment after a course or term has begun, accounts receivable is reduced. If payment is made prior to the start of a course or term, the payment is recorded as a student deposit, and the student is provided access to the online classroom when courses start, in the case of APUS, or allowed to start the term, in the case of HCN. If a payment option is confirmed, the student is allowed to start the course or term. Generally, if no receipt is confirmed or payment option secured, the student will be dropped from the online course or not allowed to start the term. Therefore, billed amounts represent charges that have been prepared and sent to students or the applicable third-party payor according to the terms agreed upon in advance. DoD tuition assistance programs are billed by branch of service on a course-by-course basis when a student starts a course, whereas Title IV programs are billed based on the courses included in a student’s term. Billed accounts receivable are considered past due if the invoice has been outstanding for more than 30 days. The allowance for doubtful accounts is based on management’s evaluation of the status of existing accounts receivable. Among other factors, management considers the age of the receivable, the anticipated source of payment and the historical allowance considerations. Consideration is also given to any specific known risk areas among the existing accounts receivable balances. Recoveries of receivables previously written off are recorded when received. The Company does not charge interest on past due accounts receivable. Property and equipment. All property and equipment is carried at cost less accumulated depreciation and amortization, except the acquired assets of HCN, which were recorded at fair value at the acquisition date. Depreciation and amortization are calculated on a straight-line basis over the estimated useful lives of the assets. For tax purposes, different methods are used. Maintenance and repairs are expensed as incurred, while other costs are capitalized if they extend the useful life of the asset. The Company’s Partnership At a Distance TM system, or PAD, is a customized student information and services system used by APUS to manage admissions, online orientation, course registrations, tuition payments, grade reporting, progress toward degrees, and various other functions. Costs associated with this system have been capitalized in accordance with Financial Accounting Standards Board Accounting Standards Codification, Subtopic 350-40, (or FASB ASC 350-40) Accounting for the Costs of Computer Software Developed or Obtained for Internal Use , and classified as property and equipment. These costs are amortized over the estimated useful life of five years. The Company also capitalizes certain costs for academic program development. These costs are transferred to property and equipment upon completion of each program and amortized over an estimated life not to exceed three years. Investments. The Company accounts for its investments in less than majority owned companies in accordance with FASB ASC 323, Investments - Equity Method and Joint Ventures . The Company applies the equity method to investments when it has the ability to exercise significant influence, but does not control the operating and financial policies of the company. This is generally represented by equity ownership of at least 20 percent but not more than 50 percent. Investments accounted for under the equity method are initially recorded at cost and subsequently adjusted by the Company’s share of equity in income or losses after the date of acquisition. The pro-rata share of the operating results of the investee is reported in the Consolidated Statements of Income as “Equity investment income / (loss).” The Company applies the cost method to investments when it does not have the ability to exercise significant influence over the operating and financial policies of the investment. Under the cost method, the investment is initially recorded at cost. Income is recognized when dividends are received from the investment. The Company periodically evaluates both the equity and cost method investments for indicators of other-than-temporary impairments. Factors the Company considers when evaluating for other-than-temporary impairments include the duration and severity of the impairment, the reasons for the decline in value, and the potential recovery period. For an investee with impairment indicators, the Company measures fair value on the basis of discounted cash flows or other appropriate valuation methods. If it is probable that the Company will not recover the carrying amount of the investment, the impairment is considered other-than-temporary and recorded in equity earnings, and the equity investment balance is reduced to its fair value accordingly. Management must exercise significant judgment in evaluating the potential impairment of its equity investments. The Company’s investments are presented on a one-line basis as “Investments” in the accompanying Consolidated Balance Sheets. Additional information regarding the Company’s investments is located in “Note 6. Investments” below, in these Consolidated Financial Statements. Goodwill and indefinite-lived intangible assets. Goodwill represents the excess of the purchase price of an acquired business over the amount assigned to the assets acquired and liabilities assumed. Goodwill is not amortized. In accordance with ASC 350, Intangibles Goodwill and Other, the Company annually assesses goodwill for impairment on or around the October 31 st , or more frequently if events and circumstances indicate that goodwill might be impaired. In connection with the Company’s November 1, 2013 acquisition of HCN, the Company recorded $38.6 million of goodwill, representing the excess of the purchase price over the amount assigned to the new assets acquired and the fair value assigned to identified intangible assets. The Company also recorded $3.7 million of indefinite-lived tangible assets as part of the HCN acquisition. In August 2016, the Company completed an interim assessment of goodwill and determined that the fair value was less than the carrying value. As a result, the Company recorded a pretax, non-cash impairment charge of $4.7 million . In conjunction with the Company’s annual assessment performed in October 2017, the Company adopted ASU 2017-04, Intangibles - Goodwill and Other: Simplifying the Test for Goodwill Impairment . The annual assessment was performed by an independent valuation firm and concluded that the fair value exceeded the carrying value; consequently, there was no impairment. Determining the fair value of HCN is judgmental in nature and requires the use of significant estimates and assumptions from management, including revenue growth rates, operating margins, and future economic and market conditions, among others. Additionally, the valuation firm’s analysis includes significant assumptions about discount rates and valuation multiples. Given the current competitive and regulatory environment, and the uncertainties regarding the related impact on HCN’s business, there can be no assurance that the estimates and assumptions made for purposes of the Company’s goodwill impairment testing will prove to be accurate predictions of the future. If the Company’s assumptions are not realized, the Company may record additional goodwill impairment charges in future periods. It is not possible at this time to determine if any such future impairment charge would result or, if it does, whether such charge would be material. Indefinite-lived intangible assets are tested at least annually for impairment by comparing the fair value of the asset to the carrying value. APEI utilizes the services of a third-party valuation firm to estimate fair value. In completing their analysis, the valuation firm uses a discounted cash flow analysis as well as other valuation methods. The discounted cash flow analysis includes significant estimates and assumptions from management, including revenue growth rates, operating margins and future economic and market conditions, among others. Additionally, the valuation firm’s analysis includes significant assumptions with respect to discount rates and assumed royalty rates. If the fair value is less than the carrying value, the asset is reduced to fair value. The 2017 annual testing concluded that the indefinite-lived assets were not impaired. For additional details regarding goodwill and indefinite-lived intangible assets refer to “Note 7. Goodwill and Intangible Assets” below in these Consolidated Financial Statements. Valuation of long-lived assets. The Company accounts for the valuation of long-lived assets under ASC 360, Accounting for the Impairment or Disposal of Long-Lived Assets. ASC 360 requires that long-lived assets and certain identifiable intangible assets be reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of the long-lived asset is measured by a comparison of the carrying amount of the asset to future undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the estimated fair value of the assets. Assets to be disposed of are reported at the lower of the carrying amount or fair value, less costs to sell. Revenue recognition. The Company records all tuition as deferred revenue when a student begins an online course, in the case of APUS, or starts a term, in the case of HCN. At the beginning of each course or term, revenue is recognized on a pro rata basis over the period of the course or term, which is, for APUS, either an eight - or sixteen -week period and, for HCN, a quarterly term. This results in deferred revenue on the Company’s Consolidated Balance Sheets that includes future revenue that has not yet been earned for courses and terms that are in progress. The revenue recognition policies of each of the Company’s reportable segments are discussed below. American Public University System. APUS’s tuition revenue varies from period to period based on the number of net course registrations and the volume of undergraduate versus graduate registrations. Students may remit tuition payments through the online registration process at any time or they may elect various payment options, including payments by sponsors, alternative loans, financial aid, or the DoD tuition assistance program which remits payments directly to APUS. If one of the various other payment options are confirmed as secured, the student is allowed to start the course. These other payment options can delay the receipt of payment up until the course starts or longer, resulting in the recording of an account receivable at the beginning of each session. Tuition revenue for sessions in progress that have not been earned by APUS is presented as deferred revenue in the accompanying Consolidated Balance Sheets. APUS refunds 100% of tuition for courses that are dropped before the conclusion of the first seven days of a course. The Company does not recognize revenue for dropped courses. After a course begins, APUS uses the following refund policy: 8-Week Course- Tuition Refund Schedule Withdrawal Date Tuition Refund Percentage Before or During Week 1 100% During Week 2 75% During Weeks 3 and 4 50% During Weeks 5 through 8 No Refund 16-Week Course- Tuition Refund Schedule Withdrawal Date Tuition Refund Percentage Before or During Week 1 100% During Week 2 100% During Weeks 3 and 4 75% During Weeks 5 through 8 50% During Weeks 9 through 16 No Refund Students affiliated with certain organizations may have an alternate refund policy. APUS recognizes revenue on a pro rata basis over the period of its courses as APUS completes the tasks entitling it to the benefits represented by such revenue. If a student withdraws during the academic term, APUS calculates the portion of tuition that is non-refundable based on the tuition refund policy and recognizes it as revenue in the period the withdrawal occurs. For those students who have an outstanding receivable balance at the date of withdrawal, APUS assesses collectability and recognizes as revenue those amounts where collectability is reasonably assured based on APUS’s history with similar student accounts. Other revenue includes charges for a technology fee per course. APUS provides a grant to cover the technology fee for students using DoD tuition assistance programs. Prior to April 2015, APUS provided a grant to cover the technology fee for students using education benefit programs administered by the U.S. Department of Veterans Affairs, or VA. After April 1, 2015, the technology fee grant was no longer applied to students using VA education benefits. APUS charged a transfer credit evaluation fee and eliminated the fee in March 2016. The transfer credit evaluation fee was for securing official transcripts on behalf of the student and evaluating the transcripts for transfer credit. Students also are charged graduation, late registration, transcript request and comprehensive examination fees, when applicable. In accordance with ASC 605-50, Accounting by a Customer (Including a Reseller) for Certain Consideration Received from a Vendor , other fees also include book purchase commissions APUS receives for graduate student book purchases and ancillary supply purchases students make directly from APUS’s preferred book vendor. Hondros College of Nursing. HCN’s tuition revenue varies from period to period based on the number of students enrolled and the programs they are enrolled in. Students may remit tuition payments at any time, or they may elect various payment options that can delay receipt of payment up until the term starts or longer. These other payment options include payments by sponsors, financial aid, alternative loans, or payment plan options. If one of the various other payment options are confirmed as secured, the student is allowed to start the term. Generally, all financial aid is awarded prior to the start of the term and requests for authorization of disbursement begin in the first week of the term. Tuition revenue for the term in progress that has not yet been earned by HCN is presented as deferred revenue in the accompanying Consolidated Balance Sheets. HCN’s refund policy complies with the rules of the Ohio State Board of Career Colleges and Schools and is applicable to each term. For a course with an on-campus or other in-person component, the date of withdrawal is determined by a student’s last attended day of clinical offering, laboratory session, or lecture. For an online course, the date of withdrawal is determined by a student’s last submitted assignment in the course. HCN uses the following refund policy: Withdrawal Date Tuition Refund Percentage Before first full calendar week of the quarter 100% During first full calendar week of the quarter 75% During second full calendar week of the quarter 50% During third full calendar week of the quarter 25% During fourth full week of the quarter No Refund Students affiliated with certain organizations may have an alternate refund policy. HCN recognizes revenue on a pro rata basis over the academic term. If a student withdrawals during the term, HCN calculates the portion of tuition that is non-refundable based on the tuition refund policy and recognizes it as revenue in the period the withdrawal occurs. Other revenue includes application fees as well as fees for testing, books and supplies, lab, technology and graduation. Deferred revenue. Deferred revenue at December 31, 2016 and 2017 was $20,639,000 and $19,374,000 , respectively. Deferred revenue includes revenue that has been received from students for courses that are still in process and from student deposits. Student deposits represent cash received from students prior to the commencement of a course and are refundable to the student in the event the student withdrawals before the start of the course. Deferred revenue included $9,158,000 and $9,129,000 of student deposits at December 31, 2016 and 2017 , respectively. The Company provides scholarships to certain students to assist them financially and promote their registration. Scholarship assistance of $7,583,000 , $ 18,021,000 and $17,851,000 was provided for the years ended December 31, 2015 , 2016 and 2017 , respectively, and is included as a reduction to revenue in the accompanying Consolidated Statements of Income. Advertising costs. Advertising costs are expensed as incurred during the year pursuant to ASC 720-35. Advertising expenses for the years ended December 31, 2015 , 2016 and 2017 were $42,226,000 , $39,450,000 and $39,829,000 , respectively, and are included in selling and promotional costs in the accompanying Consolidated Statements of Income. Income taxes. Deferred taxes are determined using the liability method, whereby deferred tax assets are recognized for deductible temporary differences and deferred tax liabilities are recognized for taxable temporary differences. Temporary differences are the differences between the reported amounts of assets and liabilities and their tax basis. As these differences reverse, they will enter into the determination of future taxable income. Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more likely than not that some portion or all of the deferred tax assets will not be realized. Deferred tax assets and liabilities are adjusted for the effects of changes in tax laws and rates on the date of enactment of such changes. As a result of the Tax Cuts and Jobs Act of 2017 signed on December 22, 2017, the Company revalued its net deferred tax liability and recorded a $3.7 million reduction in income tax expense for the year ended December 31, 2017. There were no material uncertain tax positions as of December 31, 2015 , 2016 or 2017 . Interest and penalties associated with uncertain income tax positions would be classified as income tax expense. The Company has not recorded any material interest or penalties during any of the years presented. Stock-based compensation. The Company accounts for stock-based compensation in accordance with ASC 718, Stock Compensation , which requires companies to expense share-based compensation based on fair value, and adopted ASU 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting in January 2017. Stock-based payments may include: incentive stock options or non-qualified stock options, stock appreciation rights, restricted stock, restricted stock units, dividend equivalent rights, performance shares, performance units, cash-based awards, other stock-based awards, including unrestricted shares, or any combination of the foregoing. At the present time, the Company utilizes restricted stock grants and has not issued any stock options since 2011. Stock-based compensation expense related to restricted stock grants is recognized over the vesting period using the straight-line method for the Company’s employees and the graded-vesting method for members of the Board of Directors, and is measured using the Company’s stock price on the date of the grant. The fair value of each option award is estimated at the date of grant using a Black-Scholes option-pricing model that uses certain assumptions, which have been noted in “Note 11. Stockholders’ Equity” below, in these Consolidated Financial Statements. The Company makes assumptions with respect to expected stock price volatility based on the average historical volatility of the stock prices of peers with similar attributes. In addition, the Company determines the risk free interest rate by selecting the U.S. Treasury five-year constant maturity, quoted on an investment basis in effect at the time of grant for that business day. The Company estimates forfeitures of stock-based awards at the time of grant and revise such estimates in subsequent periods if actual forfeitures differ from the original estimates. Estimates of fair value are subjective and are not intended to predict actual future events, and subsequent events are not indicative of the reasonableness of the original estimates of fair value made under FASB ASC Topic 718. Income per common share. Basic net income per common share is based on the weighted average number of shares of common stock outstanding during the period. Diluted net income per common share increases the shares used in the per share calculation by the dilutive effects of options, warrants, and restricted stock. Fair value of financial instruments. Cash equivalents are measured and recorded at fair value. The Company also measures certain financial assets at fair value for disclosure purposes, as well as on a nonrecurring basis when they are deemed to be other-than-temporary impairments. The carrying amounts of cash, accounts receivable, accounts payable and accrued liabilities approximate fair value because of the short maturity of these instruments. Fair value represents the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that is determined based on assumptions that market participants would use in pricing an asset. Assets recorded at fair value are measured and classified in accordance with a three-tier fair value hierarchy based on the observability of the inputs available in the market used to measure fair value: Level 1 - inputs to the valuation techniques that are quoted prices in active markets for identical assets or liabilities; Level 2 - inputs to the valuation techniques that are other than quoted prices but are observable for the assets or liabilities, either directly or indirectly; or Level 3 - inputs to the valuation techniques that are unobservable for the assets or liabilities. The fair value hierarchy requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The Company’s cash and cash equivalents, accounts receivable, accounts payable are all short-term in nature. As such, their carrying amounts approximate fair value and fall within Level 1 of the fair value hierarchy. Concentration of credit risk. The Company maintains its cash and cash equivalents in bank deposit accounts with various financial institutions. Cash and cash equivalent balances may exceed the FDIC insurance limit. The Company has historically not experienced any losses in such accounts. Recent Accounting Pronouncements. The Company considers the applicability and impact of all Accounting Standards Updates, or ASUs. ASUs issued but not listed below were assessed and determined to be either not applicable or expected to have minimal impact on our consolidated financial position and/or results of operations. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) . The standard is a comprehensive model to use in accounting for revenue arising from contracts with customers and supersedes the revenue recognition requirements in FASB Accounting Standards Codification, or ASC, 605, Revenue Recognition , as well as other various sections of the ASC. The core principle of ASU 2014-09 is to recognize revenue when promised goods or services are transferred to customers in an amount that reflects the consideration to which an entity expects to be entitled for those goods or services. The authoritative guidance provides a five-step analysis of transactions to determine when and how revenue is recognized. More judgment and estimates may be required within the revenue recognition process than are required under existing GAAP, including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocation the transaction price to each separate performance obligation, among other factors. The standard also includes a cohesive set of disclosure requirements including comprehensive information about the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. ASU 2014-09 was initially intended to be effective for fiscal years, and the interim periods within these fiscal years, beginning on or after December 15, 2016. In August, 2015, the FASB issued ASU 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date . This update defers for one year the effective date of ASU 2014-09. The deferral will result in this standard being effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016 including interim reporting periods within those reporting periods. Entities must use either a full retrospective approach for all periods presented in the period of adoption or a modified retrospective approach. The FASB has issued three ASUs in addition to ASU 2015-14 that amend certain aspects of ASU 2014-09: • ASU No. 2016-08, Principal versus Agent Considerations (Reporting Revenue Gross Versus Net) , issued in March 2016, clarifies certain aspects of the principal versus agent guidance; • ASU No. 2016-10, Identifying Performance Obligations and Licensing , issued in April 2016, clarifies guidance related to identifying performance obligations and licensing implementation; and • ASU No. 2016-12, Revenue from Contracts with Customers - Narrow Scope Improvements and Practical Expedients , issued in May 2016, provides amendments and practical expedients in the areas of assessing collectability, presentation of sales taxes received from customers, noncash consideration, contract modification and clarification of using the full retrospective approach to adopt ASU 2014-09. The Company has evaluated the impact the new revenue recognition standard will have on its Consolidated Financial Statements by analyzing each revenue stream, including the recommended five-step evaluation process, comparing historical accounting policies and practices to the new standard, reviewing the design and implementation of related internal controls over financial reporting, and by carrying out a management-approved implementation plan. The Company adopted the new revenue guidance effective January 1, 2018 using the modified retrospective approach. The Company has reached conclusions on all key accounting assessments related to the new standard, and anticipates the impact of this standard will not be material to its consolidated financial statements. The evaluation of each revenue stream resulted in the following conclusions: • Tuition revenue will continue to be recognized ratably over the period of instruction as the performance obligation is satisfied. • APUS’s graduation fee revenue, included in the Company’s other revenue, is currently recognized at the time the application for graduation is submitted by the student and payment is made. Under the new standard, revenue will be recognized when the performance obligation is satisfied. For the year ended December 31, 2017, APUS recognized approximately $1.1 million in graduation fee revenue, which includes approximately $0.4 million in graduation fee revenue where the performance obligation is not satisfied as of December 31, 2017. The performance obligation is expected to be satisfied by June 30, 2018. As a result, the statement of retained earnings at January 1, 2018 will be adjusted by $0.4 million to reflect the change in the new accounting guidance. This revenue will be recognized once the performance obligation is satisfied. • Revenue from all other fees remains substantially unchanged. In November 2015, the FASB issued ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes . The standard requires that deferred tax assets and deferred tax liabilities be classified as non-current on the balance sheet rather than being separated into current and non-current. This standard was effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. The guidance permitted either retrospective or prospective application. The Company adopted this ASU effective January 1, 2017 and it was applied retrospectively. As a result, the $5.1 million current deferred tax asset as of December 31, 2016 was reclassified against the $13.9 million non-current deferred tax liability on the Company’s Consolidated Balance Sheets in these Consolidated Financial Statements. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities . The standard addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. These changes will require an entity to measure, at fair value, investments in equity securities and other ownership interests in an entity and to recognize the changes in fair value within net income. ASU 2016-01 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017, and early adoption is not permitted. The Company adopted this standard effective January 1, 2018 and does not expect the adoption of this ASU to have a material impact on its Consolidated Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842)

Acquisition Accounting

Acquisition Accounting	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Acquisition Accounting	Acquisition Accounting On November 1, 2013 , the Company acquired all of the outstanding common stock of HCN, for an initial adjusted aggregate purchase price of approximately $46.3 million . The HCN acquisition was accounted for under FASB ASC Topic 805, Business Combinations, which requires the acquisition method to be used for all business combinations. Under FASB ASC Topic 805, the assets and liabilities of an acquired company are reported at business fair value along with the fair value of unrecorded intangible assets at the date of acquisition. Goodwill represents the excess of the purchase price of an acquired business over the amount assigned to the assets acquired and liabilities assumed and the fair value assigned to identifiable intangible assets. The initial purchase price allocation resulted in $38.1 million of goodwill, which is deductible for tax purposes. Intangible assets are amortized over their estimated useful lives unless they are deemed to have an indefinite life. Identified intangible assets with an indefinite life are trade name, accreditation, licensing and Title IV, and affiliate agreements as they benefit the Company indefinitely. Because HCN is wholly owned by the Company as a result of the acquisition, management has determined that push-down accounting is appropriate. As part of the transaction, the Company and the selling stockholders of HCN agreed to an election under Section 338(h)(10) of the Internal Revenue Code of 1986, as amended, as it relates to the acquisition of HCN by the Company. A Section 338(h)(10) election is an election made jointly by buyer(s) and seller(s) to treat a stock acquisition as an asset acquisition for U.S. federal income tax purposes. The acquisition resulted in a preliminary estimate of fair value of its liability to the selling stockholders related to the Section 338(h)(10) election in the amount of $150,000 , which was included in the initial goodwill allocation. Prior to December 31, 2014, the Company revised its estimate of the fair value of its liability to HCN’s selling stockholders related to the Section 338(h)(10) election to approximately $636,000 . As a result, the total adjusted aggregate purchase price and the amount of goodwill were revised to $46.8 million and $38.6 million , respectively. The fair value of identified intangible assets acquired was determined using one of the following three valuation methodologies: • Cost approach; • Income approach; or • Market approach. (In thousands) Fair value consideration transferred: Cash $ 46,128 Fair Value of IRC 338(h)(10) election 636 Total fair value consideration transferred $ 46,764 Recognized amounts of identifiable tangible assets acquired and liabilities assumed: Assets acquired $ 4,834 Liabilities assumed 4,786 Assets acquired in excess of liabilities assumed $ 48 Useful Life Recognized identified intangible assets: Student contracts and relationships 6 years $ 3,870 Trade name Indefinite 1,998 Curricula 3 years 405 Accreditation, licensing and Title IV Indefinite 1,686 Affiliate agreements Indefinite 37 Non-compete agreements 5 years 86 Total recognized identified intangible assets $ 8,082 Goodwill $ 38,634

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment Property and equipment at December 31, 2016 and 2017 consisted of the following: Useful 2016 2017 (in thousands) Land — $ 9,244 $ 9,244 Building and building improvements 27.5 - 39 years 54,691 54,408 Leasehold improvements up to 15 years 1,208 1,437 Office equipment 5 years 2,219 2,248 Computer equipment 3 years 22,492 22,736 Furniture and fixtures 7 years 8,036 8,022 Other capital assets 5 years 128 128 Software development 5 years 79,452 84,178 Program development 3 years 6,966 9,150 184,436 191,551 Accumulated depreciation and amortization 86,749 99,177 $ 97,687 $ 92,374 Assets held for sale of $2.1 million at December 31, 2016 are excluded from the $97.7 million in property and equipment in the above table. For additional information see “Note 5. Assets Held for Sale” below, in these Consolidated Financial Statements. For the year ended December 31, 2016 , the Company disposed of long-lived assets resulting in a loss of $6.0 million , primarily consisting of a loss that resulted from the abandoned development of a new student course registration system in the APEI Segment. It was no longer probable that development would be completed and the software placed in service due to programming difficulties that could not be resolved in a timely basis and without additional cost. The original carrying value of the software and incurred cost was $4.0 million . For the year ended December 31, 2017, the Company disposed of long-lived assets resulting in a loss of $2.1 million , primarily consisting of assets no longer in use. The losses on long-lived assets are included as loss on disposals of long-lived assets in these Consolidated Financial Statements. During the years ended December 31, 2015 , 2016 and 2017 , the Company recorded depreciation expense of $19,626,000 , $18,674,000 and $18,178,000 , respectively. In addition, the Company recorded amortization expense related to other assets of $894,000 , $710,000 , and $598,000 during the years ended December 31, 2015 , 2016 and 2017 , respectively.

Assets Held For Sale

Assets Held For Sale	12 Months Ended
	Dec. 31, 2017
Discontinued Operations and Disposal Groups [Abstract]
Assets Held For Sale	Assets Held For Sale Assets held for sale at December 31, 2016 represented excess real property located in Charles Town, West Virginia for the Company’s APEI Segment, which was no longer in use due to the relocation of employees to a new facility. Long-lived assets are classified as held for sale when the assets are expected to be sold within the next 12 months and meet the other relevant held for sale criteria. As such, the property was recorded at the lower of the carrying value or fair value, less cost to sell, until such time as the asset was sold. The fair value of the asset of $2.1 million , as determined by an independent appraisal, was less than the carrying value, and therefore the Company recognized a loss of $0.5 million for the year ended December 31, 2016. During the year ended December 31, 2017, the APEI segment sold the asset held for sale with a fair value of $2.1 million for a net sales price of $1.5 million . During the year ended December 31, 2017, the Company recognized a loss of $0.6 million when the asset was sold, which is included in loss on disposals of long-lived assets in these Consolidated Financial Statements. In addition, for the year ended December 31, 2016, the Company’s APEI segment sold certain excess real property located in Charles Town, West Virginia, with a carrying value of $1.1 million for a net sales price of $0.8 million . This property was no longer in use due to the relocation of employees to another facility. In connection with this sale, the Company recorded a loss on sale of $0.3 million in the year ended December 31, 2016. In connection with the items noted above, the Company’s APEI segment had a loss on the assets held for sale of $0.8 million and $0.6 million during the years ended December 31, 2016 and 2017, respectively included in loss on disposals of long-lived assets in these Consolidated Financial Statements.

Investments

Investments	12 Months Ended
	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Investments	Investments The Company accounts for its investments in less than majority owned companies in accordance with FASB ASC 323, Investments - Equity Method and Joint Ventures . The Company applies the equity method to investments when it has the ability to exercise significant influence, but does not control the operating and financial policies of the company. This is generally represented by equity ownership of at least 20% but not more than 50%. Investments accounted for under the equity method are initially recorded at cost and subsequently adjusted by the Company’s share of equity in income or losses after the date of acquisition. The pro-rata share of the operating results of the investee is reported in the Consolidated Statements of Income as “Equity investment income / (loss).” The Company applies the cost method to investments when it does not have the ability to exercise significant influence over the operating and financial policies of the investment. Under the cost method, the investment is initially recorded at cost. Income is recognized when dividends are received from the investment. The Company periodically evaluates both the equity and cost method investments for indicators of other-than-temporary impairments. Factors the Company considers when evaluating for other-than-temporary impairments include the duration and severity of the impairment, the reasons for the decline in value, and the potential recovery period. For an investee with impairment indicators, the Company measures fair value on the basis of discounted cash flows or other appropriate valuation methods. If it is probable that the Company will not recover the carrying amount of the investment, the impairment is considered other-than-temporary and recorded in equity earnings, and the equity investment balance is reduced to its fair value accordingly. Management must exercise significant judgment in evaluating the potential impairment of its equity investments. On September 30, 2012, the Company made a $6.8 million investment in preferred stock of NWHW Holdings, Inc., or NWHW Holdings, a holding company that operates an information technology training company, New Horizons Worldwide, Inc., or New Horizons, representing approximately 20% of the fully diluted equity of NWHW Holdings. During the year ended December 31, 2016, the Company received a dividend of $3.0 million from NWHW Holdings. In connection with the investment, the Company is entitled to certain rights, including the right to representation on the Board of Directors of NWHW Holdings. The Company accounts for its investment in New Horizons under the equity method of accounting. Therefore, the Company recorded the investment at cost and recognizes its share of earnings or losses in the investee in the periods for which they are reported with a corresponding adjustment in the carrying amount of the investment. On February 20, 2013, the Company made a $4.0 million investment in preferred stock of Fidelis Education, Inc., or Fidelis Education, representing approximately 22% of its fully diluted equity. On February 1, 2016 the Company made an additional $950,000 investment in preferred stock increasing its investment in Fidelis Education to approximately 23% of its fully diluted equity. Fidelis Education offers a learning relationship management platform that has the goal of improving education advising and career mentoring services offered to students as they pursue college degrees. In connection with the investment, the Company is entitled to certain rights, including the right to representation on the Board of Directors of Fidelis Education. The Company accounts for its investment in Fidelis Education under the equity method of accounting. Therefore, the Company recorded the investment at cost and recognizes its share of earnings or losses in the investee in the periods for which they are reported with a corresponding adjustment in the carrying amount of the investment. During the fourth quarter of 2017, the Company determined that the fair value of its investment in Fidelis Education was less than its carrying value and that the impairment was other-than-temporary. As a result, a $2.2 million non-cash impairment charge was recorded for the year ended December 31, 2017. This impairment charge is included in equity investment income (loss) in the Consolidated Statements of Income. On April 2, 2014, the Company made a $1.5 million investment in preferred stock of Second Avenue Software, Inc., or Second Avenue Software, representing approximately 26% of its fully diluted equity. Second Avenue Software is a game-based education software company that develops software on a proprietary and “work-for-hire” basis. In connection with the investment, the Company is entitled to certain rights, including the right to representation on the Board of Directors of Second Avenue Software. The Company accounts for its investment in Second Avenue Software under the equity method of accounting. Therefore, the Company recorded the investment at cost and recognizes its share of earnings or losses in the investee in the periods for which they are reported with a corresponding adjustment in the carrying amount of the investment. During the fourth quarter of 2017, the Company determined that the fair value of its investment in Second Avenue Software was less than its carrying value and that the impairment was other-than-temporary. As a result, the Company recorded a $0.2 million non-cash impairment charge was recorded for the year ended December 31, 2017 . This impairment charge is included in equity investment income (loss) in the Consolidated Statements of Income. On December 21, 2015, the Company made a $3.5 million investment in preferred stock of RallyPoint, an online social network for members of the military, representing approximately 14% of its fully diluted equity. The Company accounts for its investment in RallyPoint using the cost method of accounting. On October 24, 2017, the Company made an additional $0.3 million investment in preferred stock of Rally Point. Subsequent to the additional investment, the Company’s fully diluted ownership was unchanged and the Company continues to be entitled to two board seats. The Company evaluated its cost method investments for impairment as of December 31, 2017 and determined that a certain investment had an other-than-temporary impairment and as a result recorded a $0.3 million non-cash impairment charge. This impairment charge is included in equity investment income (loss) in the Consolidated Statements of Income. No other cost method investments were impaired as of December 31, 2017 . The aggregate carrying amount of the Company’s cost method investments presented on its Consolidated Balance Sheet was $3.8 million as of December 31, 2016 and December 31, 2017 . Impairment of cost method investments is evaluated annually, unless indicators of impairment exist, because it is not practicable to estimate the fair value of such investments during interim periods. The Company’s investments are presented on a one-line basis as “Investments” in the accompanying Consolidated Balance Sheets.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets In connection with its November 1, 2013 acquisition of HCN, the Company applied ASC 805, Business Combinations, using the acquisition method of accounting. The Company recorded $ 38.6 million of goodwill, representing the excess of the purchase price over the amount assigned to the net assets acquired and the fair value assigned to identified intangible assets, and recorded $8.1 million of identified intangible assets. In accordance with ASC 350, Intangibles-Goodwill and Other , the Company assesses goodwill for impairment on or around each anniversary date of the acquisition, and more frequently if events and circumstances indicate that goodwill might be impaired. Goodwill impairment testing consists of an optional qualitative assessment as well as a quantitative test. The quantitative test compares the fair value of the reporting unit to its carrying value. If the carrying value of the reporting unit is greater than zero and its fair value is greater than its carrying amount, there is no impairment. If the carrying value is greater than the fair value, the difference between the two values is recorded as an impairment. In addition to goodwill, HCN recorded $8.1 million of identifiable intangible assets at the acquisition date. HCN recorded identified intangible assets with an indefinite useful life in the aggregate amount of $3.7 million , which includes trade names, accreditation, licensing and Title IV, and affiliate agreements. HCN recorded $4.4 million of identified intangible assets with a definite useful life. At the acquisition date, the useful life assigned to each type of intangible asset with a definite useful life was as follows: Useful Life Student contracts and relationships 6 years Curricula 3 years Non-compete agreements 5 years The future amortization of intangible assets is as follows (in thousands): 2018 $ 563 2019 322 2020 and beyond — Total $ 885 In August 2016, the Company completed a qualitative assessment to determine if an interim goodwill impairment test was necessary. Due to relevant circumstances that included: (1) HCN’s under performance against internal targets; (2) the challenging higher education competitive and regulatory environment, particularly for proprietary institutions; (3) overall financial performance; and (4) the uncertain status of ACICS, the Company concluded it was more likely than not the fair value of HCN was less than its carrying amount; therefore, the Company proceeded with step one of the goodwill impairment test as of August 31, 2016. Step one of the goodwill impairment test identified that HCN’s fair value was less than the carrying value. Accordingly, step two testing was completed in order to determine the amount of the impairment. In step two, the fair value of all assets and liabilities was estimated for the purpose of deriving an estimate of the implied fair value of goodwill. The implied fair value of goodwill was then compared to the recorded goodwill to determine the amount of impairment. Step two testing indicated that the fair value of goodwill was $33.9 million or $4.7 million less than its carrying value. There was no impairment of the intangible assets. As a result, the Company recorded a pretax, non-cash charge of $4.7 million to reduce the carrying value of its goodwill. The Company utilized an independent valuation firm to determine the fair value of HCN. The independent valuation firm weighted the results of four different valuation methods: (1) discounted cash flow; (2) guideline company method; (3) guideline transaction method - comparable transactions; and (4) guideline transaction method - private equity transactions. Under the income approach, fair value was determined based on estimated discounted future cash flows of HCN. The cash flows were discounted by an estimated risk weighted-average cost of capital, which was intended to reflect the overall level of inherent risk of HCN. Under the market approach, pricing terms from other transactions in the higher education market were used to determine the value of HCN. Values derived under the four valuation methods were then weighted to estimate HCN’s enterprise value. The goodwill impairment charge recorded in the quarter ended September 30, 2016 eliminated the difference between the fair value of goodwill and the book value of goodwill. As such, future changes, including minor changes, in revenue, operating income, valuation multiples, discount rates and other inputs to the valuation process may result in future impairment charges and those charges may be material. As of October 31, 2016 and October 31, 2017, the Company completed its annual assessment of goodwill and concluded that HCN’s fair value was more than the carrying value; consequently, there was no impairment. The method and estimates used in the subsequent tests were consistent with those used in the August 31, 2016 impairment testing. Changes in the carrying amount of goodwill by reportable segment during fiscal year ending December 31, 2016 and December 31, 2017 are as follows (in thousands): APEI Segment HCN Segment Total Goodwill Goodwill as of December 31, 2015 $ — $ 38,634 $ 38,634 Impairment — (4,735 ) (4,735 ) Goodwill as of December 31, 2016 $ — $ 33,899 $ 33,899 Impairment — — — Goodwill as of December 31, 2017 $ — $ 33,899 $ 33,899 The following table presents the components of the net carrying amount of goodwill by reportable segment as of December 31, 2016 (in thousands): APEI Segment HCN Segment Total Goodwill Carrying amount of Goodwill as of December 31, 2016 $ — $ 38,634 $ 38,634 Accumulated impairment — (4,735 ) (4,735 ) Carrying amount of Goodwill as of December 31, 2016 $ — $ 33,899 $ 33,899 The following table presents the components of the net carrying amount of goodwill by reportable segment as of December 31, 2017 (in thousands): APEI Segment HCN Segment Total Goodwill Gross carrying amount of Goodwill as of December 31, 2017 $ — $ 33,899 $ 33,899 Accumulated impairment — — — Net Carrying amount of Goodwill as of December 31, 2017 $ — $ 33,899 $ 33,899 Other intangible assets, included in Other Assets on the Consolidated Balance Sheets in these Consolidated Financial Statements, consist of the following as of December 31, 2016 (in thousands): 2016 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Finite-lived intangible assets Curricula $ 405 $ 405 $ — Non-compete agreements 86 54 32 Student contracts and relationships 3,870 2,419 1,451 Total finite-lived intangible assets 4,361 2,878 1,483 Indefinite-lived intangible assets Trade name 1,998 — 1,998 Accreditation, licensing and Title IV 1,686 — 1,686 Affiliation agreements 37 — 37 Total indefinite-lived intangible assets 3,721 — 3,721 Total intangible assets $ 8,082 $ 2,878 $ 5,204 Other intangible assets consist of the following as of December 31, 2017 (in thousands): 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Finite-lived intangible assets Curricula $ 405 $ 405 $ — Non-compete agreements 86 72 14 Student contracts and relationships 3,870 2,999 871 Total finite-lived intangible assets 4,361 3,476 885 Indefinite-lived intangible assets Trade name 1,998 — 1,998 Accreditation, licensing and Title IV 1,686 — 1,686 Affiliation agreements 37 — 37 Total indefinite-lived intangible assets 3,721 — 3,721 Total intangible assets $ 8,082 $ 3,476 $ 4,606 Identified intangible assets are amortized in a manner that reflects the estimated economic benefit of the intangible assets. Curricula and Non-compete agreements are amortized on a straight-line basis. Student contracts and relationships are amortized using an accelerated method. Determining the fair value of HCN requires judgment and the use of significant estimates and assumptions, including revenue growth rates, EBITDA margins, discount rates and future market conditions, among others. Given the current competitive and regulatory environment, and the uncertainties regarding the related impact on HCN’s business, there can be no assurance that the estimates and assumptions made for purposes of the Company’s interim and annual goodwill impairment tests will prove to be accurate predictions of the future. If the Company’s assumptions are not realized, the Company may record additional goodwill impairment charges in future periods. It is not possible at this time to determine if any such future impairment charge would result or whether such charge would be material.

Operating Leases

Operating Leases	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Operating Leases	Operating Leases The APEI Segment leases office space in Maryland and Virginia under operating leases that expire through June 2023 . HCN operates five campuses in Ohio, located in the suburban areas of Cincinnati, Cleveland, Columbus, Dayton and Toledo under operating leases that expire through June 2029 . Rent expense related to the APEI Segment’s operating leases was $1,094,000 , $584,000 and $677,000 for the years ended December 31, 2015 , 2016 and 2017 , respectively. Rent expense related to the HCN Segment’s operating leases was $2,347,000 , $2,528,000 , and $2,729,000 for the years ended December 31, 2015 , 2016 and 2017 , respectively. A majority of the leases provide for the payment of taxes, maintenance, insurance and certain other expenses applicable to the leased premises. The minimum rental commitments due under the operating leases are as follows (in thousands): Years Ending December 31, Combined 2018 $ 2,380 2019 2,350 2020 2,406 2021 2,424 2022 2,366 2023 and beyond 4,236 Total minimum rental commitment $ 16,162

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The components of income tax expense for the years ended December 31, 2015 , 2016 and 2017 were as follows (in thousands): 2015 2016 2017 Current income tax expense: Federal $ 17,910 $ 13,518 $ 11,989 State 2,322 1,877 1,998 20,232 15,395 13,987 Deferred tax expense: Federal (241 ) (424 ) (2,810 ) State 81 (31 ) 316 (160 ) (455 ) (2,494 ) Income Tax Expense $ 20,072 $ 14,940 $ 11,493 The tax effects of principal temporary differences are as follows (in thousands): 2016 2017 Deferred tax assets Stock option compensation expense $ 1,057 $ 415 Allowance for doubtful accounts 3,079 1,569 Accrued vacation and severance 798 679 Deferred rent — 67 Restricted stock 1,874 922 Investment 168 — Total deferred tax assets 6,976 3,652 Deferred tax liabilities Income tax deductible capitalized software development costs (10,886 ) (6,066 ) Goodwill (941 ) (1,284 ) Property and equipment (2,208 ) (1,489 ) Prepaid expenses (1,716 ) (1,017 ) Investment — (77 ) Total deferred tax liabilities (15,751 ) (9,933 ) Deferred tax liabilities, net $ (8,775 ) $ (6,281 ) Income tax expense differs from the amount of tax determined by applying the United States Federal income tax rates to pretax income and loss due to the application of state apportionment laws, permanent tax differences, and the impact of the change in the federal statutory rate as follows (in thousands): 2015 2016 2017 Amount % Amount % Amount % Tax expense at statutory rate $ 18,370 35.00 % $ 13,683 35.00 % $ 11,415 35.00 % State taxes, net 1,590 3.03 % 1,278 3.27 % 1,626 4.98 % Permanent differences 278 0.53 % 221 0.56 % 2,060 6.31 % Change in statutory rate — — % — — % (3,741 ) (11.47 )% Other (166 ) (0.32 )% (242 ) (0.62 )% 133 0.42 % $ 20,072 38.24 % $ 14,940 38.21 % $ 11,493 35.24 % On December 22, 2017 the U.S. Tax Cuts and Jobs Act, or Tax Act, was enacted by the U.S. government. Among other provisions, the Tax Act reduced the federal corporate tax rate to 21% from the existing maximum rate of 35%, effective January 1, 2018. The Company recorded a tax benefit of $3.7 million related to the revaluation of the its net deferred tax liabilities for the year ended December 31, 2017. The Company anticipates that its effective tax rate, prior to discrete tax benefits, may range from approximately 27% to 29% . While the Company is able to make reasonable estimates of the impact of the reduction in its effective tax rate, the final impact of the Tax Act may differ from these estimates. Permanent differences in the table above are mainly attributable to minority investment earnings and/or losses including other-than-temporary impairment charges, stock compensation, nondeductible meals and entertainment expenses, and non-deductible employer contributions to the American Public Education, Inc. Employee Stock Purchase Plan, or ESPP. The Company is subject to U.S. federal income taxes as well as income tax of multiple state jurisdictions. For U.S. federal and state tax purposes, tax years 2014 - 2016 remain open to examination.

Other Employee Benefits

Other Employee Benefits	12 Months Ended
	Dec. 31, 2017
Postemployment Benefits [Abstract]
Other Employee Benefits	Other Employee Benefits The Company has established a tax deferred 401(k) retirement plan that provides retirement benefits to all of its eligible employees. Participants may elect to contribute up to 60% of their gross annual earnings not to exceed ERISA and IRS limits. The plan provides for Company discretionary profit sharing contributions at matching percentages. Employees immediately vest 100% in all salary reduction contributions and employer contributions. In June 2015, the Company’s 401(k) retirement plan was amended so that effective August 31, 2015, the Company’s 401(k) retirement plan no longer allows participants to invest future contributions in the Company’s common stock. The Company’s 401(k) retirement plan completely removed the Company’s common stock as an investment election on June 30, 2016. Any of the Company's common stock held by 401(k) retirement plan participants as of June 30, 2016 was sold and automatically re-allocated to an age-appropriate mutual fund. The Company made discretionary contributions to the plan of $3,309,000 , $3,284,000 and $3,824,000 for the years ended December 31, 2015 , 2016 and 2017 , respectively. In November 2007, the Company adopted the American Public Education, Inc. Employee Stock Purchase Plan, or the ESPP, which was implemented effective July 1, 2008 with quarterly enrollment periods. Eligible participants may only enter the plan and establish their withholdings at the start of an enrollment period. Participating employees may withdraw from the plan and end payroll deductions any time up to five days before the share purchase date and funds will be returned to them. Under the ESPP, participating employees may purchase shares of the Company’s common stock, subject to certain limitations, at 85% of its fair market value on the last day of the quarterly period. The total value of contributions per participant may not exceed $21,000 annually or the value of the common stock purchased per participant cannot exceed $25,000 . There were initially 100,000 shares of common stock available for purchase by participating employees under the ESPP. On June 13, 2014, the Company’s stockholders approved an amendment to the ESPP to increase the number of shares of the Company’s common stock available for issuance under the plan by 100,000 shares, extend the term of the ESPP to March 7, 2024, and make other administrative changes. Shares purchased in the open market for issuance to employees pursuant to the plan for the years ended December 31, 2015 , 2016 and 2017 were as follows: Purchase Date Shares Common Stock Fair Value Purchase Price Compensation Expense March 31, 2015 4,322 $ 29.98 $ 25.49 $ 19,406 June 30, 2015 5,443 $ 25.72 $ 21.86 $ 21,010 September 30, 2015 4,939 $ 23.45 $ 19.93 $ 17,385 December 31, 2015 6,822 $ 18.61 $ 15.82 $ 19,033 Total/Weighted Average 21,526 $ 23.80 $ 20.02 $ 76,834 March 31, 2016 4,617 $ 20.63 $ 17.54 $ 14,287 June 30, 2016 3,617 $ 28.10 $ 23.89 $ 15,228 September 30, 2016 4,991 $ 19.81 $ 16.84 $ 14,823 December 31, 2016 3,717 $ 24.80 $ 21.08 $ 13,827 Total/Weighted Average 16,942 $ 22.90 $ 19.46 $ 58,165 March 31, 2017 4,161 $ 22.90 $ 19.47 $ 14,293 June 30, 2017 3,535 $ 23.65 $ 20.10 $ 12,540 September 30, 2017 4,613 $ 21.15 $ 17.98 $ 14,623 December 31, 2017 3,065 $ 25.80 $ 21.93 $ 11,862 Total/Weighted Average 15,374 $ 23.13 $ 19.66 $ 53,318

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Stock Incentive Plans On March 31, 2017 the Company’s Board of Directors adopted the American Public Education, Inc. 2017 Omnibus Incentive Plan, or 2017 Incentive Plan, and on May 12, 2017, or the Effective Date, the Company’s stockholders approved the 2017 Incentive Plan, at which time the 2017 Incentive Plan became effective. Upon effectiveness of the 2017 Incentive Plan, the Company ceased making awards under the American Public Education, Inc. 2011 Omnibus Incentive Plan, or the 2011 Incentive Plan. The 2017 Incentive Plan allows the Company to grant up to 1,675,000 shares, as well as shares of the Company’s common stock that were available for issuance under the 2011 Incentive Plan as of the Effective Date. In addition, the number of shares of common stock available under the 2017 Incentive Plan will be increased from time to time by the number of shares subject to outstanding awards granted under the 2011 Incentive Plan, the American Public Education, Inc. 2007 Omnibus Incentive Plan and the American Public Education, Inc. 2002 Stock Incentive Plan that terminate by expiration, forfeiture, cancellation or otherwise without issuance of such shares following the Effective Date. Prior to 2012, the Company issued a mix of stock options and restricted stock, but since 2011 the Company has no t issued any stock options. The 2017 Plan includes a provision that allows individuals who have reached certain service and retirement eligibility criteria on the date of grant an accelerated service period of one year. The Company recognizes compensation expense for these individuals over the accelerated period. Restricted Stock and Restricted Stock Unit Awards Stock-based compensation expense related to restricted stock and restricted stock unit grants is expensed over the vesting period using the straight-line method for Company employees and the graded-vesting method for members of the Board of Directors, and is measured using APEI’s stock price on the date of grant. The Company also estimates forfeitures of share-based awards at the time of grant and revises such estimates in subsequent periods if actual forfeitures differ from original estimates. The table below sets forth the restricted stock and restricted stock unit activity for the year ended December 31, 2015 : Number of Shares Weighted Average Grant Price and Fair Value Non vested, December 31, 2014 360,769 $ 37.03 Shares granted 127,469 35.15 Vested shares (164,144 ) 37.85 Shares forfeited (30,675 ) 36.76 Non vested, December 31, 2015 293,419 $ 35.86 The table below sets forth the restricted stock and restricted stock unit activity for the year ended December 31, 2016 : Number of Shares Weighted Average Grant Price and Fair Value Non vested, December 31, 2015 293,419 $ 35.86 Shares granted 336,434 16.34 Vested shares (152,714 ) 35.83 Shares forfeited (39,168 ) 25.46 Non vested, December 31, 2016 437,971 $ 21.54 The table below sets forth the restricted stock and restricted stock unit activity for the year ended December 31, 2017 : Number of Shares Weighted Average Grant Price and Fair Value Non vested, December 31, 2016 437,971 $ 21.54 Shares granted 279,729 23.35 Vested shares (212,984 ) 25.98 Shares forfeited (43,454 ) 21.04 Non vested, December 31, 2017 461,262 $ 20.91 There were no shares of restricted stock or restricted stock units excluded in the computation of diluted net income per common share for the year ended December 31, 2017 . At December 31, 2017 , total unrecognized compensation expense in the amount of $4.5 million relates to non-vested restricted stock and restricted stock units which will be recognized over a weighted average period of 1.7 years. As a result of termination of employment, the Company accepted the following common shares for forfeiture: 22,066 shares for $815,886 in 2015 , 31,370 shares for $611,335 in 2016 , and 43,454 shares for $914,272 in 2017 . Option Awards The fair value of each option award is estimated at the date of grant using a Black-Scholes option-pricing model. Prior to 2012, the Company calculated the expected term of stock option awards using the “simplified method” in accordance with Securities and Exchange Commission Staff Accounting Bulletins No. 107 and 110 because the Company lacked historical data and was unable to make reasonable assumptions regarding the future. The Company makes assumptions with respect to expected stock price volatility based on the average historical volatility of peers with similar attributes. In addition, the Company determines the risk free interest rate by selecting the U.S. Treasury five-year constant maturity, quoted on an investment basis in effect at the time of grant for that business day. Estimates of fair value are subjective and are not intended to predict actual future events, and subsequent events are not necessarily indicative of the reasonableness of the original estimates of fair value made under FASB ASC Topic 718. Options previously granted vest ratably over periods of three to five years and expire in seven to ten years from the date of grant. A summary of the status of the Company’s Stock Incentive Plans as of December 31, 2015 and the changes during the periods then ended is as follows: Number of Options Weighted Average Exercise Price Weighted Average Contractual Life (years) Aggregate Intrinsic Value (in thousands) Outstanding, December 31, 2014 434,401 $ 30.04 Options granted — — Awards exercised (55,382 ) 3.29 Options forfeited (49,147 ) 35.97 Outstanding, December 31, 2015 329,872 $ 33.65 1.30 $ 359 Exercisable, December 31, 2015 329,872 $ 33.65 1.30 $ 359 A summary of the status of the Company’s Stock Incentive Plans as of December 31, 2016 and the changes during the periods then ended is as follows: Number of Options Weighted Average Exercise Price Weighted Average Contractual Life (years) Aggregate Intrinsic Value (in thousands) Outstanding, December 31, 2015 329,872 $ 33.65 Options granted — — Awards exercised (16,878 ) 7.00 Options forfeited (53,024 ) 37.09 Outstanding, December 31, 2016 259,969 $ 34.68 0.53 $ 246 Exercisable, December 31, 2016 259,969 $ 34.68 0.53 $ 246 A summary of the status of the Company’s Stock Incentive Plans as of December 31, 2017 and the changes during the periods then ended is as follows: Number of Options Weighted Average Exercise Price Weighted Average Contractual Life (years) Aggregate Intrinsic Value (in thousands) Outstanding, December 31, 2016 259,969 $ 34.68 Options granted — — Awards exercised (14,002 ) 6.99 Options forfeited (136,351 ) 35.24 Outstanding, December 31, 2017 109,616 $ 37.52 0.01 $ — Exercisable, December 31, 2017 109,616 $ 37.52 0.01 $ — The following table summarizes information regarding stock option exercises: Year Ended December 31, 2015 2016 2017 (In thousands) Proceeds from stock options exercised $ 182 $ 118 $ 98 Intrinsic value of stock options exercised $ 1,057 $ 290 $ 194 Tax benefit from exercises $ 54 $ 94 $ 60 There were 317,961 , 247,993 and 123,267 anti-dilutive stock options excluded from the calculation of diluted net income per common share for the years ended December 31, 2015 , 2016 and 2017 , respectively. Stock-Based Compensation Expense As of December 31, 2017, there were 30,246 shares subject to outstanding awards under the 2017 Incentive Plan, 431,016 shares subject to outstanding awards under the 2011 Incentive Plan, and 109,616 shares subject to outstanding awards under the 2007 Incentive Plan and the 2002 Stock Plan. For the years ended December 31, 2015 , 2016 and 2017 , the Company recognized stock-based compensation expense as follows: Year Ended December 31, 2015 2016 2017 (In thousands) Instructional costs and services $ 1,598 $ 1,497 $ 1,310 Selling and promotional 684 672 789 General and administrative 3,630 3,042 4,147 Total stock-based compensation expense $ 5,912 $ 5,211 $ 6,246 The Company recognized income tax benefits of $2,467,000 , $2,064,000 , and $2,473,000 from vested restricted stock and restricted stock units for the years ended December 31, 2015 , 2016 and 2017 , respectively. Repurchase During the year ended December 31, 2015 , the Company repurchased 1,322,846 shares of the Company’s common stock, par value $0.01 per share. The chart and footnotes below provide detail as to the Company’s repurchases during the period. Total Number of Shares Purchased Average Price Paid per Share Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs Maximum Number of Shares that May Yet Be Purchased Under the Plans or Programs (1) Maximum Number (or Approximate Dollar Value) of Shares that May Yet Be Purchased Under the Plans or Programs (2) (3) January 1, 2015 — $ — — 155,695 $ 15,027,043 January 1, 2015 - January 31, 2015 — $ — — 263,523 15,027,043 February 1, 2015 - February 28, 2015 — $ — — 263,523 15,027,043 March 1, 2015 - March 31, 2015 100,000 $ 31.69 100,000 213,523 13,442,543 April 1, 2015 - April 30, 2015 203,820 $ 30.84 203,820 147,289 9,220,841 May 1, 2015 - May 31, 2015 200,000 $ 25.59 200,000 147,289 4,102,131 June 1, 2015 - June 30, 2015 160,000 $ 24.93 160,000 164,093 15,114,029 July 1, 2015 - July 31, 2015 — $ — — 164,093 15,114,029 August 1, 2015 - August 31, 2015 — $ — — 164,093 15,114,029 September 1, 2015 - September 30, 2015 129,849 $ 23.15 129,849 164,093 12,107,835 October 1, 2015 - October 31, 2015 211,040 $ 23.19 211,040 164,562 7,214,395 November 1, 2015 - November 30, 2015 199,391 $ 22.11 199,391 164,562 2,806,575 December 1, 2015 - December 31, 2015 118,746 $ 22.39 118,746 164,562 148,008 Total 1,322,846 $ 25.34 1,322,846 164,562 $ 148,008 During the year ended December 31, 2016 , the Company did not repurchase shares of the Company’s common stock, par value $0.01 per share, other than shares deemed to have been repurchased to satisfy employee minimum tax withholding requirements in connection with the vesting of restricted stock grants. The chart and footnotes below provide detail as to the Company’s repurchases during the period. Total Number of Shares Purchased Average Price Paid per Share Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs Maximum Number of Shares that May Yet Be Purchased Under the Plans or Programs (2) Maximum Number (or Approximate Dollar Value) of Shares that May Yet Be Purchased Under the Plans or Programs (2) (3) January 1, 2016 — $ — — 164,562 $ 148,008 January 1, 2016 – January 31, 2016 — — — 480,645 148,008 February 1, 2016 – February 29, 2016 — — — 480,645 148,008 March 1, 2016 – March 31, 2016 — — — 480,645 148,008 April 1, 2016 – April 30, 2016 — — — 481,497 148,008 May 1, 2016 – May 31, 2016 — — — 481,497 148,008 June 1, 2016 – June 30, 2016 — — — 495,378 148,008 July 1, 2016 – July 31, 2016 — — — 500,687 148,008 August 1, 2016 – August 31, 2016 — — — 500,687 148,008 September 1, 2016 – September 30, 2016 — — — 500,687 148,008 October 1, 2016 – October 31, 2016 — — — 500,996 148,008 November 1, 2016 – November 30, 2016 — — — 500,996 148,008 December 1, 2016 – December 31, 2016 — — — 500,996 148,008 Total — — — 500,996 $ 148,008 During the year ended December 31, 2017 , the Company did not repurchase shares of the Company’ s common stock, par value $0.01 per share, other than shares deemed to have been repurchased to satisfy employee minimum tax withholding requirements in connection with the vesting of restricted stock grants. The chart and footnotes below provide detail as to the Company’s repurchases during the period. Total Number of Shares Purchased Average Price Paid per Share Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs Maximum Number of Shares that May Yet Be Purchased Under the Plans or Programs (2) Maximum Number (or Approximate Dollar Value) of Shares that May Yet Be Purchased Under the Plans or Programs (2) (3) January 1, 2017 — $ — — 500,996 $ 148,008 January 1, 2017 – January 31, 2017 — — — 744,718 148,008 February 1, 2017 – February 28, 2017 — — — 744,718 148,008 March 1, 2017 – March 31, 2017 — — — 744,718 148,008 April 1, 2017 – April 30, 2017 — — — 745,782 148,008 May 1, 2017 – May 31, 2017 — — — 757,398 148,008 June 1, 2017 – June 30, 2017 — — — 779,133 148,008 July 1, 2017 – July 31, 2017 — — — 779,930 148,008 August 1, 2017 – August 31, 2017 — — — 779,930 148,008 September 1, 2017 – September 30, 2017 — — — 779,930 148,008 October 1, 2017 – October 31, 2017 — — — 780,725 148,008 November 1, 2017 – November 30, 2017 — — — 780,725 148,008 December 1, 2017 – December 31, 2017 — — — 780,725 148,008 Total — — — 780,725 $ 148,008 (1) On December 9, 2011, the Company’s Board of Directors approved a stock repurchase program for its common stock, under which the Company may annually purchase up to the cumulative number of shares issued or deemed issued in that year under the Company’s equity incentive and stock purchase plans. Repurchases may be made from time to time in the open market at prevailing market prices or in privately negotiated transactions based on business and market conditions. The stock repurchase program does not obligate us to repurchase any shares, may be suspended or discontinued at any time, and is funded using the Company’s available cash. (2) On May 14, 2012, the Company’s Board of Directors authorized a program to repurchase up to $20 million of shares of the Company’s common stock. On each of March 14, 2013, June 13, 2014, and June 12, 2015 the Company’s Board of Directors increased the authorization by an additional $15 million of shares, for a cumulative increase of $45 million of shares and a total authorization of $65 million of shares. Subject to market conditions, applicable legal requirements and other factors, the repurchases may be made from time to time in the open market or privately negotiated transactions. The authorization does not obligate the Company to acquire any shares, and purchases may be commenced or suspended at any time based on market conditions and other factors as the Company deems appropriate. (3) The Company was deemed to have repurchased 49,512 and 68,065 shares of common stock forfeited by employees to satisfy minimum tax-withholding requirements in connection with the vesting of restricted stock grants during the years ended December 31, 2016 and 2017 , respectively. During the year ended December 31, 2015, the Company was deemed to have repurchased 56,272 shares of common stock forfeited by employees to satisfy minimum tax withholding requirements in connect with the vesting of restricted stock grants and to cover the exercise and minimum tax-withholding requirements of expiring stock options. These repurchases were not part of the stock repurchase program authorized by the Company’s Board of Directors. During the year ended December 31, 2015 , the Company repurchased and retired 1,322,846 , shares of common stock. No shares of common stock were repurchased and retired in 2016 and 2017.

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies The Company accrues for costs associated with contingencies including, but not limited to, regulatory compliance and legal matters when such costs are probable and can be reasonably estimated. Liabilities established to provide for contingencies are adjusted as further information develops, circumstances change, or contingencies are resolved. The Company bases these accruals on management’s estimate of such costs, which may vary from the ultimate costs and expenses, associated with any such contingency. From time to time the Company may be involved in legal matters in the normal course of its business. On August 3, 2017, the Company received from the Attorney General of the Commonwealth of Massachusetts a Civil Investigative Demand, or CID, dated July 31, 2017, relating to an investigation of alleged unfair or deceptive acts or practices by AMU in connection with the recruitment and retention of students and the financing of education. The CID requires the production of documents and information relating to recruitment, enrollment, job placement and other matters. The Company continues to cooperate with the Attorney General’s office and cannot predict the eventual scope, duration or outcome of the investigation at this time, including whether any potential loss, or range of potential losses, is probable or reasonably estimable.

Concentration

Concentration	12 Months Ended
	Dec. 31, 2017
Risks and Uncertainties [Abstract]
Concentration	Concentration APUS students utilize various payment sources and programs to finance their education expenses, including funds from: Department of Defense, or DoD, tuition assistance programs; federal student aid from Title IV programs; and education benefit programs administered by the U.S. Department of Veteran’s Affairs, or VA, education benefit programs; as well as cash and other sources. Reductions in or changes to DoD tuition assistance, VA education benefits, Title IV programs and other payments sources could have a significant impact on the Company’s operations. As of December 31, 2017 approximately 54% of APUS students self-reported that they served in the military on active duty at the time of initial enrollment. Active duty military students generally take fewer courses per year on average than non-military students. A summary of APEI Segment revenue derived from students by primary funding source for the years ended December 31, 2015 , 2016 and 2017 is as follows: Year Ended December 31, 2015 2016 2017 DoD tuition assistance programs 35% 36% 37% Title IV programs 32% 29% 27% VA education benefits 21% 22% 23% Cash and other sources 12% 13% 13% A summary of HCN Segment revenue derived from students by primary funding source for the years ended December 31, 2015 , 2016 and 2017 is as follows: Year Ended December 31, 2015 2016 2017 Title IV programs 86% 84% 83% Cash and other sources 11% 13% 14% VA education benefits 2% 3% 2% A reduction in, or change to, any of these programs could have a significant impact on the Company’s operations and financial condition.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment Information	Segment Information The Company has two operating segments that are managed in the following reportable segments: • American Public Education Segment, or APEI Segment, and • Hondros College of Nursing Segment, or HCN Segment. In accordance with FASB ASC Topic 280, Segment Reporting , the chief operating decision-maker has been identified as the Chief Executive Officer. The Chief Executive Officer reviews operating results to make decisions about allocating resources and assessing performance for APEI and HCN. A summary of financial information by reportable segment is as follows (in thousands): Year Ended December 31, 2015 2016 2017 Revenue American Public Education Segment $ 297,439 $ 283,941 $ 265,246 Hondros College of Nursing Segment 30,471 29,198 34,002 Total Revenue $ 327,910 $ 313,139 $ 299,248 Depreciation and Amortization American Public Education Segment $ 19,337 $ 18,029 $ 17,376 Hondros College of Nursing Segment 1,183 1,355 1,400 Total Depreciation and Amortization $ 20,520 $ 19,384 $ 18,776 Income from operations before interest income and income taxes American Public Education Segment $ 48,967 $ 41,916 $ 30,873 Hondros College of Nursing Segment 3,314 (3,640 ) 3,986 Total income from operations before interest income and income taxes $ 52,281 $ 38,276 $ 34,859 Interest Income, Net American Public Education Segment $ 115 $ 116 $ 185 Hondros College of Nursing Segment — — — Total Interest Income, Net $ 115 $ 116 $ 185 Income Tax Expense American Public Education Segment $ 18,788 $ 16,322 $ 10,289 Hondros College of Nursing Segment 1,284 (1,382 ) 1,204 Total Income Tax Expense $ 20,072 $ 14,940 $ 11,493 Capital Expenditures American Public Education Segment $ 24,541 $ 12,912 $ 10,414 Hondros College of Nursing Segment 1,461 914 441 Total Capital Expenditures $ 26,002 $ 13,826 $ 10,855 A summary of the Company’s consolidated assets by reportable segment is as follows (in thousands): As of December 31, 2016 2017 Assets American Public Education Segment $ 267,260 $ 287,656 Hondros College of Nursing Segment 48,360 51,382 Total Assets $ 315,620 $ 339,038

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events APUS’s Title IV compliance audit for the year ended December 31, 2016 identified a finding related to return of Title IV funds calculations that were not properly computed. In the 2016 Title IV compliance audit Final Audit Determination letter dated January 29, 2018, ED conveyed its finding that funds had not been returned timely. Under ED regulations, if the institution’s annual Title IV compliance audit for either of its two most recently completed fiscal years finds that Title IV funds were not returned timely for 5% or more of students sampled in the audit, the institution generally must submit an irrevocable letter of credit. ED also noted that a similar finding had been made in an open program review with respect to which APUS has not yet received a program review report. In connection with the finding, ED indicated that APUS must post an irrevocable letter of credit equal to 25% of the total amount of Title IV program funds that should have been returned during calendar year 2016, which results in a requirement for a letter of credit of approximately $700,000 . On February 15, 2018, APUS requested that ED reconsider its finding that APUS had made untimely returns. HCN has an in-process application for accreditation by ABHES, an accrediting agency that is recognized by ED. On February 6, 2018, ABHES notified HCN that at its January 2018 meeting, ABHES acted to defer action on HCN’s application for initial accreditation until ABHES’s May 2018 meeting. If HCN does not obtain accreditation from ABHES, or if ACICS does not receive new initial recognition from ED, by June 12, 2018, HCN will lose its ability to participate in the Title IV programs. The ineligibility of HCN to participate in Title IV programs would have a material adverse effect on HCN’s enrollments and on our revenue, results of operations, and financial condition.

Quarterly Financial Summary (un

Quarterly Financial Summary (unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Summary (unaudited)	Quarterly Financial Summary (unaudited) The following unaudited consolidated interim financial information presented should be read in conjunction with other information included in the Company’s consolidated financial statements. In the opinion of management, the following unaudited consolidated financial information reflects all adjustments necessary for the fair presentation of the results of interim periods. Historical results are not necessarily indicative of the results of operations to be expected for future periods. The following tables set forth selected unaudited quarterly financial information for each of the Company’s last eight quarters: 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter (in thousands, except per share data) 2017 Revenue $ 75,688 $ 72,196 $ 73,279 $ 78,085 Income from operations before income taxes 8,318 6,333 7,616 12,777 Net income 4,509 3,829 4,366 8,417 Net income per common share: Basic $ 0.28 $ 0.24 $ 0.27 $ 0.52 Diluted $ 0.28 $ 0.23 $ 0.27 $ 0.51 2016 Revenue $ 83,966 $ 76,745 $ 73,803 $ 78,625 Income from operations before income taxes 16,007 10,697 429 11,259 Net income 10,340 6,596 326 6,893 Net income per common share: Basic $ 0.64 $ 0.41 $ 0.02 $ 0.43 Diluted $ 0.64 $ 0.41 $ 0.02 $ 0.42

Schedule II Valuation and Quali

Schedule II Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2017
Valuation and Qualifying Accounts [Abstract]
Schedule II Valuation and Qualifying Accounts	Schedule II Valuation and Qualifying Accounts Balance at Additions/ (Reductions) Write-Offs Balance at (in thousands) Year ended December 31, 2017: American Public Education Segment $ 4,712 $ 2,631 $ (4,090 ) $ 3,253 Hondros College of Nursing Segment 3,365 2,040 (2,382 ) 3,023 Allowance for receivables $ 8,077 $ 4,671 $ (6,472 ) $ 6,276 Year ended December 31, 2016: American Public Education Segment $ 10,286 $ 4,861 $ (10,435 ) $ 4,712 Hondros College of Nursing Segment 2,726 1,898 (1,259 ) 3,365 Allowance for receivables $ 13,012 $ 6,759 $ (11,694 ) $ 8,077 Year ended December 31, 2015: American Public Education Segment $ 8,461 $ 11,203 $ (9,378 ) $ 10,286 Hondros College of Nursing Segment 2,238 1,511 (1,023 ) 2,726 Allowance for receivables $ 10,699 $ 12,714 $ (10,401 ) $ 13,012

Significant Accounting Polici24

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of accounting	Basis of presentation and accounting. The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United Sates, or GAAP. Certain prior year amounts have been reclassified for comparative purposes to conform with the 2017 presentation.
Principles of consolidation	Principles of consolidation. The accompanying consolidated financial statements include accounts of APEI and its wholly owned subsidiaries. All material intercompany transactions and balances have been eliminated in consolidation.
Use of estimates	Use of estimates. In preparing financial statements in conformity with GAAP, the Company is required to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses during the reporting period. The Company evaluates these estimates and judgments on an ongoing basis and bases its estimates on experience, current and expected future conditions and various other assumptions that the Company believes are reasonable under the circumstances. Actual results could differ from those estimates.
Cash and cash equivalents	Cash and cash equivalents. The Company considers all short-term highly liquid investments with maturities of three months or less when purchased to be cash equivalents. Cash and cash equivalents consist of demand deposits with financial institutions, money market funds invested in securities backed by the U.S. government and U.S. Treasury bills. Cash and cash equivalents are Level 1 assets in the fair value reporting hierarchy.
Restricted cash	Restricted cash. Cash and cash equivalents includes funds held for students for unbilled educational services that were received from Title IV programs. As a trustee of these Title IV program funds, the Company is required to maintain and restrict these funds pursuant to the terms of the program participation agreement with the U.S. Department of Education. Restricted cash on the Company’s Consolidated Balance Sheets as of December 31, 2016 and 2017 was $1.6 million and $2.3 million , respectively. Changes in restricted cash that represent funds held for students as described above are included in cash flows from operating activities on the Consolidated Statements of Cash Flows because these restricted funds are a core activity of operations.
Accounts receivable	Accounts receivable. Course tuition is recorded as accounts receivable and deferred revenue at the time students begin a course or term. Students may remit tuition payments at any time or they may elect various other payment options with payment terms extending beyond the start of the course or term. These other payment options include payments by sponsors, financial aid, alternative loans, or tuition assistance programs that remit payments directly to the subsidiary. When a student remits payment after a course or term has begun, accounts receivable is reduced. If payment is made prior to the start of a course or term, the payment is recorded as a student deposit, and the student is provided access to the online classroom when courses start, in the case of APUS, or allowed to start the term, in the case of HCN. If a payment option is confirmed, the student is allowed to start the course or term. Generally, if no receipt is confirmed or payment option secured, the student will be dropped from the online course or not allowed to start the term. Therefore, billed amounts represent charges that have been prepared and sent to students or the applicable third-party payor according to the terms agreed upon in advance. DoD tuition assistance programs are billed by branch of service on a course-by-course basis when a student starts a course, whereas Title IV programs are billed based on the courses included in a student’s term. Billed accounts receivable are considered past due if the invoice has been outstanding for more than 30 days. The allowance for doubtful accounts is based on management’s evaluation of the status of existing accounts receivable. Among other factors, management considers the age of the receivable, the anticipated source of payment and the historical allowance considerations. Consideration is also given to any specific known risk areas among the existing accounts receivable balances. Recoveries of receivables previously written off are recorded when received. The Company does not charge interest on past due accounts receivable.
Property and equipment	Property and equipment. All property and equipment is carried at cost less accumulated depreciation and amortization, except the acquired assets of HCN, which were recorded at fair value at the acquisition date. Depreciation and amortization are calculated on a straight-line basis over the estimated useful lives of the assets. For tax purposes, different methods are used. Maintenance and repairs are expensed as incurred, while other costs are capitalized if they extend the useful life of the asset. The Company’s Partnership At a Distance TM system, or PAD, is a customized student information and services system used by APUS to manage admissions, online orientation, course registrations, tuition payments, grade reporting, progress toward degrees, and various other functions. Costs associated with this system have been capitalized in accordance with Financial Accounting Standards Board Accounting Standards Codification, Subtopic 350-40, (or FASB ASC 350-40) Accounting for the Costs of Computer Software Developed or Obtained for Internal Use , and classified as property and equipment. These costs are amortized over the estimated useful life of five years. The Company also capitalizes certain costs for academic program development. These costs are transferred to property and equipment upon completion of each program and amortized over an estimated life not to exceed three years.
Investments	Investments. The Company accounts for its investments in less than majority owned companies in accordance with FASB ASC 323, Investments - Equity Method and Joint Ventures . The Company applies the equity method to investments when it has the ability to exercise significant influence, but does not control the operating and financial policies of the company. This is generally represented by equity ownership of at least 20 percent but not more than 50 percent. Investments accounted for under the equity method are initially recorded at cost and subsequently adjusted by the Company’s share of equity in income or losses after the date of acquisition. The pro-rata share of the operating results of the investee is reported in the Consolidated Statements of Income as “Equity investment income / (loss).” The Company applies the cost method to investments when it does not have the ability to exercise significant influence over the operating and financial policies of the investment. Under the cost method, the investment is initially recorded at cost. Income is recognized when dividends are received from the investment. The Company periodically evaluates both the equity and cost method investments for indicators of other-than-temporary impairments. Factors the Company considers when evaluating for other-than-temporary impairments include the duration and severity of the impairment, the reasons for the decline in value, and the potential recovery period. For an investee with impairment indicators, the Company measures fair value on the basis of discounted cash flows or other appropriate valuation methods. If it is probable that the Company will not recover the carrying amount of the investment, the impairment is considered other-than-temporary and recorded in equity earnings, and the equity investment balance is reduced to its fair value accordingly. Management must exercise significant judgment in evaluating the potential impairment of its equity investments. The Company’s investments are presented on a one-line basis as “Investments” in the accompanying Consolidated Balance Sheets. Additional information regarding the Company’s investments is located in “Note 6. Investments” below, in these Consolidated Financial Statements.
Goodwill and indefinite-lived intangible assets	Goodwill and indefinite-lived intangible assets. Goodwill represents the excess of the purchase price of an acquired business over the amount assigned to the assets acquired and liabilities assumed. Goodwill is not amortized. In accordance with ASC 350, Intangibles Goodwill and Other, the Company annually assesses goodwill for impairment on or around the October 31 st , or more frequently if events and circumstances indicate that goodwill might be impaired. In connection with the Company’s November 1, 2013 acquisition of HCN, the Company recorded $38.6 million of goodwill, representing the excess of the purchase price over the amount assigned to the new assets acquired and the fair value assigned to identified intangible assets. The Company also recorded $3.7 million of indefinite-lived tangible assets as part of the HCN acquisition. In August 2016, the Company completed an interim assessment of goodwill and determined that the fair value was less than the carrying value. As a result, the Company recorded a pretax, non-cash impairment charge of $4.7 million . In conjunction with the Company’s annual assessment performed in October 2017, the Company adopted ASU 2017-04, Intangibles - Goodwill and Other: Simplifying the Test for Goodwill Impairment . The annual assessment was performed by an independent valuation firm and concluded that the fair value exceeded the carrying value; consequently, there was no impairment. Determining the fair value of HCN is judgmental in nature and requires the use of significant estimates and assumptions from management, including revenue growth rates, operating margins, and future economic and market conditions, among others. Additionally, the valuation firm’s analysis includes significant assumptions about discount rates and valuation multiples. Given the current competitive and regulatory environment, and the uncertainties regarding the related impact on HCN’s business, there can be no assurance that the estimates and assumptions made for purposes of the Company’s goodwill impairment testing will prove to be accurate predictions of the future. If the Company’s assumptions are not realized, the Company may record additional goodwill impairment charges in future periods. It is not possible at this time to determine if any such future impairment charge would result or, if it does, whether such charge would be material. Indefinite-lived intangible assets are tested at least annually for impairment by comparing the fair value of the asset to the carrying value. APEI utilizes the services of a third-party valuation firm to estimate fair value. In completing their analysis, the valuation firm uses a discounted cash flow analysis as well as other valuation methods. The discounted cash flow analysis includes significant estimates and assumptions from management, including revenue growth rates, operating margins and future economic and market conditions, among others. Additionally, the valuation firm’s analysis includes significant assumptions with respect to discount rates and assumed royalty rates. If the fair value is less than the carrying value, the asset is reduced to fair value. The 2017 annual testing concluded that the indefinite-lived assets were not impaired.
Valuation of long-lived assets	Valuation of long-lived assets. The Company accounts for the valuation of long-lived assets under ASC 360, Accounting for the Impairment or Disposal of Long-Lived Assets. ASC 360 requires that long-lived assets and certain identifiable intangible assets be reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of the long-lived asset is measured by a comparison of the carrying amount of the asset to future undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the estimated fair value of the assets. Assets to be disposed of are reported at the lower of the carrying amount or fair value, less costs to sell.
Revenue recognition	Revenue recognition. The Company records all tuition as deferred revenue when a student begins an online course, in the case of APUS, or starts a term, in the case of HCN. At the beginning of each course or term, revenue is recognized on a pro rata basis over the period of the course or term, which is, for APUS, either an eight - or sixteen -week period and, for HCN, a quarterly term. This results in deferred revenue on the Company’s Consolidated Balance Sheets that includes future revenue that has not yet been earned for courses and terms that are in progress. The revenue recognition policies of each of the Company’s reportable segments are discussed below. American Public University System. APUS’s tuition revenue varies from period to period based on the number of net course registrations and the volume of undergraduate versus graduate registrations. Students may remit tuition payments through the online registration process at any time or they may elect various payment options, including payments by sponsors, alternative loans, financial aid, or the DoD tuition assistance program which remits payments directly to APUS. If one of the various other payment options are confirmed as secured, the student is allowed to start the course. These other payment options can delay the receipt of payment up until the course starts or longer, resulting in the recording of an account receivable at the beginning of each session. Tuition revenue for sessions in progress that have not been earned by APUS is presented as deferred revenue in the accompanying Consolidated Balance Sheets. APUS refunds 100% of tuition for courses that are dropped before the conclusion of the first seven days of a course. The Company does not recognize revenue for dropped courses. After a course begins, APUS uses the following refund policy: 8-Week Course- Tuition Refund Schedule Withdrawal Date Tuition Refund Percentage Before or During Week 1 100% During Week 2 75% During Weeks 3 and 4 50% During Weeks 5 through 8 No Refund 16-Week Course- Tuition Refund Schedule Withdrawal Date Tuition Refund Percentage Before or During Week 1 100% During Week 2 100% During Weeks 3 and 4 75% During Weeks 5 through 8 50% During Weeks 9 through 16 No Refund Students affiliated with certain organizations may have an alternate refund policy. APUS recognizes revenue on a pro rata basis over the period of its courses as APUS completes the tasks entitling it to the benefits represented by such revenue. If a student withdraws during the academic term, APUS calculates the portion of tuition that is non-refundable based on the tuition refund policy and recognizes it as revenue in the period the withdrawal occurs. For those students who have an outstanding receivable balance at the date of withdrawal, APUS assesses collectability and recognizes as revenue those amounts where collectability is reasonably assured based on APUS’s history with similar student accounts. Other revenue includes charges for a technology fee per course. APUS provides a grant to cover the technology fee for students using DoD tuition assistance programs. Prior to April 2015, APUS provided a grant to cover the technology fee for students using education benefit programs administered by the U.S. Department of Veterans Affairs, or VA. After April 1, 2015, the technology fee grant was no longer applied to students using VA education benefits. APUS charged a transfer credit evaluation fee and eliminated the fee in March 2016. The transfer credit evaluation fee was for securing official transcripts on behalf of the student and evaluating the transcripts for transfer credit. Students also are charged graduation, late registration, transcript request and comprehensive examination fees, when applicable. In accordance with ASC 605-50, Accounting by a Customer (Including a Reseller) for Certain Consideration Received from a Vendor , other fees also include book purchase commissions APUS receives for graduate student book purchases and ancillary supply purchases students make directly from APUS’s preferred book vendor. Hondros College of Nursing. HCN’s tuition revenue varies from period to period based on the number of students enrolled and the programs they are enrolled in. Students may remit tuition payments at any time, or they may elect various payment options that can delay receipt of payment up until the term starts or longer. These other payment options include payments by sponsors, financial aid, alternative loans, or payment plan options. If one of the various other payment options are confirmed as secured, the student is allowed to start the term. Generally, all financial aid is awarded prior to the start of the term and requests for authorization of disbursement begin in the first week of the term. Tuition revenue for the term in progress that has not yet been earned by HCN is presented as deferred revenue in the accompanying Consolidated Balance Sheets. HCN’s refund policy complies with the rules of the Ohio State Board of Career Colleges and Schools and is applicable to each term. For a course with an on-campus or other in-person component, the date of withdrawal is determined by a student’s last attended day of clinical offering, laboratory session, or lecture. For an online course, the date of withdrawal is determined by a student’s last submitted assignment in the course. HCN uses the following refund policy: Withdrawal Date Tuition Refund Percentage Before first full calendar week of the quarter 100% During first full calendar week of the quarter 75% During second full calendar week of the quarter 50% During third full calendar week of the quarter 25% During fourth full week of the quarter No Refund Students affiliated with certain organizations may have an alternate refund policy. HCN recognizes revenue on a pro rata basis over the academic term. If a student withdrawals during the term, HCN calculates the portion of tuition that is non-refundable based on the tuition refund policy and recognizes it as revenue in the period the withdrawal occurs. Other revenue includes application fees as well as fees for testing, books and supplies, lab, technology and graduation. Deferred revenue. Deferred revenue at December 31, 2016 and 2017 was $20,639,000 and $19,374,000 , respectively. Deferred revenue includes revenue that has been received from students for courses that are still in process and from student deposits. Student deposits represent cash received from students prior to the commencement of a course and are refundable to the student in the event the student withdrawals before the start of the course. Deferred revenue included $9,158,000 and $9,129,000 of student deposits at December 31, 2016 and 2017 , respectively. The Company provides scholarships to certain students to assist them financially and promote their registration. Scholarship assistance of $7,583,000 , $ 18,021,000 and $17,851,000 was provided for the years ended December 31, 2015 , 2016 and 2017 , respectively, and is included as a reduction to revenue in the accompanying Consolidated Statements of Income.
Advertising costs	Advertising costs. Advertising costs are expensed as incurred during the year pursuant to ASC 720-35. Advertising expenses for the years ended December 31, 2015 , 2016 and 2017 were $42,226,000 , $39,450,000 and $39,829,000 , respectively, and are included in selling and promotional costs in the accompanying Consolidated Statements of Income.
Income taxes	Income taxes. Deferred taxes are determined using the liability method, whereby deferred tax assets are recognized for deductible temporary differences and deferred tax liabilities are recognized for taxable temporary differences. Temporary differences are the differences between the reported amounts of assets and liabilities and their tax basis. As these differences reverse, they will enter into the determination of future taxable income. Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more likely than not that some portion or all of the deferred tax assets will not be realized. Deferred tax assets and liabilities are adjusted for the effects of changes in tax laws and rates on the date of enactment of such changes. As a result of the Tax Cuts and Jobs Act of 2017 signed on December 22, 2017, the Company revalued its net deferred tax liability and recorded a $3.7 million reduction in income tax expense for the year ended December 31, 2017. There were no material uncertain tax positions as of December 31, 2015 , 2016 or 2017 . Interest and penalties associated with uncertain income tax positions would be classified as income tax expense. The Company has not recorded any material interest or penalties during any of the years presented.
Stock-based compensation	Stock-based compensation. The Company accounts for stock-based compensation in accordance with ASC 718, Stock Compensation , which requires companies to expense share-based compensation based on fair value, and adopted ASU 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting in January 2017. Stock-based payments may include: incentive stock options or non-qualified stock options, stock appreciation rights, restricted stock, restricted stock units, dividend equivalent rights, performance shares, performance units, cash-based awards, other stock-based awards, including unrestricted shares, or any combination of the foregoing. At the present time, the Company utilizes restricted stock grants and has not issued any stock options since 2011. Stock-based compensation expense related to restricted stock grants is recognized over the vesting period using the straight-line method for the Company’s employees and the graded-vesting method for members of the Board of Directors, and is measured using the Company’s stock price on the date of the grant. The fair value of each option award is estimated at the date of grant using a Black-Scholes option-pricing model that uses certain assumptions, which have been noted in “Note 11. Stockholders’ Equity” below, in these Consolidated Financial Statements. The Company makes assumptions with respect to expected stock price volatility based on the average historical volatility of the stock prices of peers with similar attributes. In addition, the Company determines the risk free interest rate by selecting the U.S. Treasury five-year constant maturity, quoted on an investment basis in effect at the time of grant for that business day. The Company estimates forfeitures of stock-based awards at the time of grant and revise such estimates in subsequent periods if actual forfeitures differ from the original estimates. Estimates of fair value are subjective and are not intended to predict actual future events, and subsequent events are not indicative of the reasonableness of the original estimates of fair value made under FASB ASC Topic 718.
Income per common share	Income per common share. Basic net income per common share is based on the weighted average number of shares of common stock outstanding during the period. Diluted net income per common share increases the shares used in the per share calculation by the dilutive effects of options, warrants, and restricted stock.
Fair value of financial instruments	Fair value of financial instruments. Cash equivalents are measured and recorded at fair value. The Company also measures certain financial assets at fair value for disclosure purposes, as well as on a nonrecurring basis when they are deemed to be other-than-temporary impairments. The carrying amounts of cash, accounts receivable, accounts payable and accrued liabilities approximate fair value because of the short maturity of these instruments. Fair value represents the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that is determined based on assumptions that market participants would use in pricing an asset. Assets recorded at fair value are measured and classified in accordance with a three-tier fair value hierarchy based on the observability of the inputs available in the market used to measure fair value: Level 1 - inputs to the valuation techniques that are quoted prices in active markets for identical assets or liabilities; Level 2 - inputs to the valuation techniques that are other than quoted prices but are observable for the assets or liabilities, either directly or indirectly; or Level 3 - inputs to the valuation techniques that are unobservable for the assets or liabilities. The fair value hierarchy requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The Company’s cash and cash equivalents, accounts receivable, accounts payable are all short-term in nature. As such, their carrying amounts approximate fair value and fall within Level 1 of the fair value hierarchy.
Concentration of credit risk	Concentration of credit risk. The Company maintains its cash and cash equivalents in bank deposit accounts with various financial institutions. Cash and cash equivalent balances may exceed the FDIC insurance limit. The Company has historically not experienced any losses in such accounts.
Recent Accounting pronouncements	Recent Accounting Pronouncements. The Company considers the applicability and impact of all Accounting Standards Updates, or ASUs. ASUs issued but not listed below were assessed and determined to be either not applicable or expected to have minimal impact on our consolidated financial position and/or results of operations. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) . The standard is a comprehensive model to use in accounting for revenue arising from contracts with customers and supersedes the revenue recognition requirements in FASB Accounting Standards Codification, or ASC, 605, Revenue Recognition , as well as other various sections of the ASC. The core principle of ASU 2014-09 is to recognize revenue when promised goods or services are transferred to customers in an amount that reflects the consideration to which an entity expects to be entitled for those goods or services. The authoritative guidance provides a five-step analysis of transactions to determine when and how revenue is recognized. More judgment and estimates may be required within the revenue recognition process than are required under existing GAAP, including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocation the transaction price to each separate performance obligation, among other factors. The standard also includes a cohesive set of disclosure requirements including comprehensive information about the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. ASU 2014-09 was initially intended to be effective for fiscal years, and the interim periods within these fiscal years, beginning on or after December 15, 2016. In August, 2015, the FASB issued ASU 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date . This update defers for one year the effective date of ASU 2014-09. The deferral will result in this standard being effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016 including interim reporting periods within those reporting periods. Entities must use either a full retrospective approach for all periods presented in the period of adoption or a modified retrospective approach. The FASB has issued three ASUs in addition to ASU 2015-14 that amend certain aspects of ASU 2014-09: • ASU No. 2016-08, Principal versus Agent Considerations (Reporting Revenue Gross Versus Net) , issued in March 2016, clarifies certain aspects of the principal versus agent guidance; • ASU No. 2016-10, Identifying Performance Obligations and Licensing , issued in April 2016, clarifies guidance related to identifying performance obligations and licensing implementation; and • ASU No. 2016-12, Revenue from Contracts with Customers - Narrow Scope Improvements and Practical Expedients , issued in May 2016, provides amendments and practical expedients in the areas of assessing collectability, presentation of sales taxes received from customers, noncash consideration, contract modification and clarification of using the full retrospective approach to adopt ASU 2014-09. The Company has evaluated the impact the new revenue recognition standard will have on its Consolidated Financial Statements by analyzing each revenue stream, including the recommended five-step evaluation process, comparing historical accounting policies and practices to the new standard, reviewing the design and implementation of related internal controls over financial reporting, and by carrying out a management-approved implementation plan. The Company adopted the new revenue guidance effective January 1, 2018 using the modified retrospective approach. The Company has reached conclusions on all key accounting assessments related to the new standard, and anticipates the impact of this standard will not be material to its consolidated financial statements. The evaluation of each revenue stream resulted in the following conclusions: • Tuition revenue will continue to be recognized ratably over the period of instruction as the performance obligation is satisfied. • APUS’s graduation fee revenue, included in the Company’s other revenue, is currently recognized at the time the application for graduation is submitted by the student and payment is made. Under the new standard, revenue will be recognized when the performance obligation is satisfied. For the year ended December 31, 2017, APUS recognized approximately $1.1 million in graduation fee revenue, which includes approximately $0.4 million in graduation fee revenue where the performance obligation is not satisfied as of December 31, 2017. The performance obligation is expected to be satisfied by June 30, 2018. As a result, the statement of retained earnings at January 1, 2018 will be adjusted by $0.4 million to reflect the change in the new accounting guidance. This revenue will be recognized once the performance obligation is satisfied. • Revenue from all other fees remains substantially unchanged. In November 2015, the FASB issued ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes . The standard requires that deferred tax assets and deferred tax liabilities be classified as non-current on the balance sheet rather than being separated into current and non-current. This standard was effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. The guidance permitted either retrospective or prospective application. The Company adopted this ASU effective January 1, 2017 and it was applied retrospectively. As a result, the $5.1 million current deferred tax asset as of December 31, 2016 was reclassified against the $13.9 million non-current deferred tax liability on the Company’s Consolidated Balance Sheets in these Consolidated Financial Statements. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities . The standard addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. These changes will require an entity to measure, at fair value, investments in equity securities and other ownership interests in an entity and to recognize the changes in fair value within net income. ASU 2016-01 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017, and early adoption is not permitted. The Company adopted this standard effective January 1, 2018 and does not expect the adoption of this ASU to have a material impact on its Consolidated Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). This standard requires entities that lease assets to recognize on the balance sheet the assets and liabilities for the rights and obligations created by those leases in addition to disclosing certain key information about leasing arrangements. Entities may elect not to recognize lease assets and liabilities for most leases with terms of 12 months or less. Expenses related to finance leases will be the sum of interest on the lease obligation and amortization of the right-of use asset and expenses related to operating leases will generally be recognized on a straight-line basis. In transition, lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. This standard is effective for fiscal years, and the interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted. The Company does not plan to early adopt and is currently evaluating the impact this standard will have on its Consolidated Financial Statements. In March 2016, the FASB issued ASU No. 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting , changing how entities account for certain aspects of share-based payments to employees. The new guidance requires excess tax benefits and tax deficiencies to be recognized as income tax expense or benefit in the income statement, and could introduce volatility to the Company’s provision for income taxes. Excess tax benefits must be presented as an operating activity on the statement of cash flows rather than a financing activity. ASU 2016-09 requires companies to make an accounting policy election at the time of adoption to either estimate the number of awards that are expected to vest (consistent with existing U.S. GAAP) or account for forfeitures when they occur. The forfeiture election provision must be applied using a retrospective transition approach, with a cumulative-effect adjustment recorded to retained earnings as of the beginning of the period of adoption. The new guidance is effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. The Company has elected the forfeiture option to continue to estimate the number of awards that are expected to vest. The adoption of ASU 2016-09 increased the Company’s income tax expense by approximately $0.5 million for the year ended December 31, 2017. The Company anticipates an increase in its reported income tax expense between $0.2 million and $0.4 million in the first quarter of 2018 due to expiring stock options with an option price greater than the current stock price. Other increases in income tax expense may occur throughout the year for the vesting of restricted stock, determined by the stock price at the end of each reporting period. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses, which is included in ASC Topic 326, Measurement of Credit Losses on Financial Instruments . The new guidance revises the accounting requirements related to the measurement of credit losses and will require entities to measure all expected credit losses for financial assets based on historical experience, current conditions and reasonable and supportable forecasts about collectability. Assets must be presented in the financial statements at the net amount expected to be collected. The guidance will be effective for the fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted with fiscal years beginning after December 15, 2018. The Company does not plan to early adopt and does not expect the adoption of this ASU to have a material impact on its Consolidated Financial Statements. In August 2016, the FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments , which is included in FASB ASC Topic 230, Statement of Cash Flows . The new guidance clarifies how companies present and classify certain cash receipts and cash payments in the statement of cash flows, including contingent consideration payments made after a business combination and distributions received from equity method investees. The guidance is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years, with early adoption permitted. The Company adopted this standard effective January 1, 2018 and does not expect the adoption of this ASU to have a material impact on its Consolidated Financial Statements. In October 2016, the FASB issued ASU No. 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory , requiring entities to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The new guidance is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted if in the first interim period an entity issues interim financial statements. ASU 2016-16 must be applied on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. The Company adopted this standard effective January 1, 2018 and does not expect the adoption of this ASU to have a material impact on its Consolidated Financial Statements. In November 2016, the FASB issued ASU No. 2016-18, Restricted Cash , which is included in FASB Accounting standards Codification (ASC) Topic 230, Statement of Cash Flows . The new guidance requires that amounts generally described as restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The guidance is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years, with early adoption permitted. The Company adopted this standard effective January 1, 2018 and does not expect the adoption of this ASU to have a material impact on its Consolidated Financial Statements. In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business , which provides a framework for entities to use when determining whether a set of assets and activities constitutes a business. The guidance is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years, and should be applied prospectively. Early adoption is permitted. The Company prospectively adopted this standard effective January 1, 2018, and does not expect the adoption of this ASU to have a material impact on its Consolidated Financial Statements. In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment , which eliminates step two from the goodwill impairment test. Instead, if the carrying amount of a reporting unit exceeds its fair value, an impairment loss should be recognized in an amount equal to the excess, but limited to the total amount of goodwill allocated to the reporting unit. The guidance must be applied on a prospective basis and disclosure of the nature of and reason for the change in accounting principle is required upon transition. ASU 2017-04 is effective for fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company adopted ASU 2017-04 in conjunction with its 2017 annual impairment test of HCN’s goodwill and adoption of ASU 2017-04 did not have a material impact on its Consolidated Financial Statements. In May 2017, the FASB issued ASU No. 2017-09, Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting , which provides guidance about which changes to the terms and conditions of share-based payment awards require an entity to apply modification accounting. ASU 2017-09 is effective for all entities for annual periods, and interim periods within those annual periods, beginning after December 15, 2017. Early adoption is permitted. The guidance should be applied prospectively to an award modified on or after the adoption date. The Company prospectively adopted this standard effective January 1, 2018 and does not expect the adoption of this ASU to have a material impact on its Consolidated Financial Statements.

Significant Accounting Polici25

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
APUS
Segment Reporting Information [Line Items]
Schedule of refund policy	After a course begins, APUS uses the following refund policy: 8-Week Course- Tuition Refund Schedule Withdrawal Date Tuition Refund Percentage Before or During Week 1 100% During Week 2 75% During Weeks 3 and 4 50% During Weeks 5 through 8 No Refund 16-Week Course- Tuition Refund Schedule Withdrawal Date Tuition Refund Percentage Before or During Week 1 100% During Week 2 100% During Weeks 3 and 4 75% During Weeks 5 through 8 50% During Weeks 9 through 16 No Refund
HCN
Segment Reporting Information [Line Items]
Schedule of refund policy	HCN uses the following refund policy: Withdrawal Date Tuition Refund Percentage Before first full calendar week of the quarter 100% During first full calendar week of the quarter 75% During second full calendar week of the quarter 50% During third full calendar week of the quarter 25% During fourth full week of the quarter No Refund

Acquisition Accounting (Tables)

Acquisition Accounting (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Schedule of fair value of identified intangible assets acquired	(In thousands) Fair value consideration transferred: Cash $ 46,128 Fair Value of IRC 338(h)(10) election 636 Total fair value consideration transferred $ 46,764 Recognized amounts of identifiable tangible assets acquired and liabilities assumed: Assets acquired $ 4,834 Liabilities assumed 4,786 Assets acquired in excess of liabilities assumed $ 48 Useful Life Recognized identified intangible assets: Student contracts and relationships 6 years $ 3,870 Trade name Indefinite 1,998 Curricula 3 years 405 Accreditation, licensing and Title IV Indefinite 1,686 Affiliate agreements Indefinite 37 Non-compete agreements 5 years 86 Total recognized identified intangible assets $ 8,082 Goodwill $ 38,634

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Schedule of property and equipment	Property and equipment at December 31, 2016 and 2017 consisted of the following: Useful 2016 2017 (in thousands) Land — $ 9,244 $ 9,244 Building and building improvements 27.5 - 39 years 54,691 54,408 Leasehold improvements up to 15 years 1,208 1,437 Office equipment 5 years 2,219 2,248 Computer equipment 3 years 22,492 22,736 Furniture and fixtures 7 years 8,036 8,022 Other capital assets 5 years 128 128 Software development 5 years 79,452 84,178 Program development 3 years 6,966 9,150 184,436 191,551 Accumulated depreciation and amortization 86,749 99,177 $ 97,687 $ 92,374

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of identified intangible assets with definite life	At the acquisition date, the useful life assigned to each type of intangible asset with a definite useful life was as follows: Useful Life Student contracts and relationships 6 years Curricula 3 years Non-compete agreements 5 years
Schedule of future amortization of intangible assets	The future amortization of intangible assets is as follows (in thousands): 2018 $ 563 2019 322 2020 and beyond — Total $ 885
Schedule of changes in carrying amount of goodwill by reportable segments	Changes in the carrying amount of goodwill by reportable segment during fiscal year ending December 31, 2016 and December 31, 2017 are as follows (in thousands): APEI Segment HCN Segment Total Goodwill Goodwill as of December 31, 2015 $ — $ 38,634 $ 38,634 Impairment — (4,735 ) (4,735 ) Goodwill as of December 31, 2016 $ — $ 33,899 $ 33,899 Impairment — — — Goodwill as of December 31, 2017 $ — $ 33,899 $ 33,899 The following table presents the components of the net carrying amount of goodwill by reportable segment as of December 31, 2016 (in thousands): APEI Segment HCN Segment Total Goodwill Carrying amount of Goodwill as of December 31, 2016 $ — $ 38,634 $ 38,634 Accumulated impairment — (4,735 ) (4,735 ) Carrying amount of Goodwill as of December 31, 2016 $ — $ 33,899 $ 33,899 The following table presents the components of the net carrying amount of goodwill by reportable segment as of December 31, 2017 (in thousands): APEI Segment HCN Segment Total Goodwill Gross carrying amount of Goodwill as of December 31, 2017 $ — $ 33,899 $ 33,899 Accumulated impairment — — — Net Carrying amount of Goodwill as of December 31, 2017 $ — $ 33,899 $ 33,899
Schedule of other intangible assets	Other intangible assets, included in Other Assets on the Consolidated Balance Sheets in these Consolidated Financial Statements, consist of the following as of December 31, 2016 (in thousands): 2016 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Finite-lived intangible assets Curricula $ 405 $ 405 $ — Non-compete agreements 86 54 32 Student contracts and relationships 3,870 2,419 1,451 Total finite-lived intangible assets 4,361 2,878 1,483 Indefinite-lived intangible assets Trade name 1,998 — 1,998 Accreditation, licensing and Title IV 1,686 — 1,686 Affiliation agreements 37 — 37 Total indefinite-lived intangible assets 3,721 — 3,721 Total intangible assets $ 8,082 $ 2,878 $ 5,204 Other intangible assets consist of the following as of December 31, 2017 (in thousands): 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Finite-lived intangible assets Curricula $ 405 $ 405 $ — Non-compete agreements 86 72 14 Student contracts and relationships 3,870 2,999 871 Total finite-lived intangible assets 4,361 3,476 885 Indefinite-lived intangible assets Trade name 1,998 — 1,998 Accreditation, licensing and Title IV 1,686 — 1,686 Affiliation agreements 37 — 37 Total indefinite-lived intangible assets 3,721 — 3,721 Total intangible assets $ 8,082 $ 3,476 $ 4,606

Operating Leases (Tables)

Operating Leases (Tables)	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Schedule of minimum rental commitment due under the operating leases	The minimum rental commitments due under the operating leases are as follows (in thousands): Years Ending December 31, Combined 2018 $ 2,380 2019 2,350 2020 2,406 2021 2,424 2022 2,366 2023 and beyond 4,236 Total minimum rental commitment $ 16,162

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of components of income tax expense	The components of income tax expense for the years ended December 31, 2015 , 2016 and 2017 were as follows (in thousands): 2015 2016 2017 Current income tax expense: Federal $ 17,910 $ 13,518 $ 11,989 State 2,322 1,877 1,998 20,232 15,395 13,987 Deferred tax expense: Federal (241 ) (424 ) (2,810 ) State 81 (31 ) 316 (160 ) (455 ) (2,494 ) Income Tax Expense $ 20,072 $ 14,940 $ 11,493
Schedule of tax effects of principal temporary differences	The tax effects of principal temporary differences are as follows (in thousands): 2016 2017 Deferred tax assets Stock option compensation expense $ 1,057 $ 415 Allowance for doubtful accounts 3,079 1,569 Accrued vacation and severance 798 679 Deferred rent — 67 Restricted stock 1,874 922 Investment 168 — Total deferred tax assets 6,976 3,652 Deferred tax liabilities Income tax deductible capitalized software development costs (10,886 ) (6,066 ) Goodwill (941 ) (1,284 ) Property and equipment (2,208 ) (1,489 ) Prepaid expenses (1,716 ) (1,017 ) Investment — (77 ) Total deferred tax liabilities (15,751 ) (9,933 ) Deferred tax liabilities, net $ (8,775 ) $ (6,281 )
Schedule of difference of income tax expense from the United States Federal income tax rates	Income tax expense differs from the amount of tax determined by applying the United States Federal income tax rates to pretax income and loss due to the application of state apportionment laws, permanent tax differences, and the impact of the change in the federal statutory rate as follows (in thousands): 2015 2016 2017 Amount % Amount % Amount % Tax expense at statutory rate $ 18,370 35.00 % $ 13,683 35.00 % $ 11,415 35.00 % State taxes, net 1,590 3.03 % 1,278 3.27 % 1,626 4.98 % Permanent differences 278 0.53 % 221 0.56 % 2,060 6.31 % Change in statutory rate — — % — — % (3,741 ) (11.47 )% Other (166 ) (0.32 )% (242 ) (0.62 )% 133 0.42 % $ 20,072 38.24 % $ 14,940 38.21 % $ 11,493 35.24 %

Other Employee Benefits (Tables

Other Employee Benefits (Tables)	12 Months Ended
	Dec. 31, 2017
Postemployment Benefits [Abstract]
Schedule of shares purchased in open market for employees	Shares purchased in the open market for issuance to employees pursuant to the plan for the years ended December 31, 2015 , 2016 and 2017 were as follows: Purchase Date Shares Common Stock Fair Value Purchase Price Compensation Expense March 31, 2015 4,322 $ 29.98 $ 25.49 $ 19,406 June 30, 2015 5,443 $ 25.72 $ 21.86 $ 21,010 September 30, 2015 4,939 $ 23.45 $ 19.93 $ 17,385 December 31, 2015 6,822 $ 18.61 $ 15.82 $ 19,033 Total/Weighted Average 21,526 $ 23.80 $ 20.02 $ 76,834 March 31, 2016 4,617 $ 20.63 $ 17.54 $ 14,287 June 30, 2016 3,617 $ 28.10 $ 23.89 $ 15,228 September 30, 2016 4,991 $ 19.81 $ 16.84 $ 14,823 December 31, 2016 3,717 $ 24.80 $ 21.08 $ 13,827 Total/Weighted Average 16,942 $ 22.90 $ 19.46 $ 58,165 March 31, 2017 4,161 $ 22.90 $ 19.47 $ 14,293 June 30, 2017 3,535 $ 23.65 $ 20.10 $ 12,540 September 30, 2017 4,613 $ 21.15 $ 17.98 $ 14,623 December 31, 2017 3,065 $ 25.80 $ 21.93 $ 11,862 Total/Weighted Average 15,374 $ 23.13 $ 19.66 $ 53,318

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Summary of restricted stock and restricted stock units activity	The table below sets forth the restricted stock and restricted stock unit activity for the year ended December 31, 2015 : Number of Shares Weighted Average Grant Price and Fair Value Non vested, December 31, 2014 360,769 $ 37.03 Shares granted 127,469 35.15 Vested shares (164,144 ) 37.85 Shares forfeited (30,675 ) 36.76 Non vested, December 31, 2015 293,419 $ 35.86 The table below sets forth the restricted stock and restricted stock unit activity for the year ended December 31, 2016 : Number of Shares Weighted Average Grant Price and Fair Value Non vested, December 31, 2015 293,419 $ 35.86 Shares granted 336,434 16.34 Vested shares (152,714 ) 35.83 Shares forfeited (39,168 ) 25.46 Non vested, December 31, 2016 437,971 $ 21.54 The table below sets forth the restricted stock and restricted stock unit activity for the year ended December 31, 2017 : Number of Shares Weighted Average Grant Price and Fair Value Non vested, December 31, 2016 437,971 $ 21.54 Shares granted 279,729 23.35 Vested shares (212,984 ) 25.98 Shares forfeited (43,454 ) 21.04 Non vested, December 31, 2017 461,262 $ 20.91
Summary of status of stock incentive plans and changes during periods	A summary of the status of the Company’s Stock Incentive Plans as of December 31, 2015 and the changes during the periods then ended is as follows: Number of Options Weighted Average Exercise Price Weighted Average Contractual Life (years) Aggregate Intrinsic Value (in thousands) Outstanding, December 31, 2014 434,401 $ 30.04 Options granted — — Awards exercised (55,382 ) 3.29 Options forfeited (49,147 ) 35.97 Outstanding, December 31, 2015 329,872 $ 33.65 1.30 $ 359 Exercisable, December 31, 2015 329,872 $ 33.65 1.30 $ 359 A summary of the status of the Company’s Stock Incentive Plans as of December 31, 2016 and the changes during the periods then ended is as follows: Number of Options Weighted Average Exercise Price Weighted Average Contractual Life (years) Aggregate Intrinsic Value (in thousands) Outstanding, December 31, 2015 329,872 $ 33.65 Options granted — — Awards exercised (16,878 ) 7.00 Options forfeited (53,024 ) 37.09 Outstanding, December 31, 2016 259,969 $ 34.68 0.53 $ 246 Exercisable, December 31, 2016 259,969 $ 34.68 0.53 $ 246 A summary of the status of the Company’s Stock Incentive Plans as of December 31, 2017 and the changes during the periods then ended is as follows: Number of Options Weighted Average Exercise Price Weighted Average Contractual Life (years) Aggregate Intrinsic Value (in thousands) Outstanding, December 31, 2016 259,969 $ 34.68 Options granted — — Awards exercised (14,002 ) 6.99 Options forfeited (136,351 ) 35.24 Outstanding, December 31, 2017 109,616 $ 37.52 0.01 $ — Exercisable, December 31, 2017 109,616 $ 37.52 0.01 $ —
Summary of information regarding stock option exercises	The following table summarizes information regarding stock option exercises: Year Ended December 31, 2015 2016 2017 (In thousands) Proceeds from stock options exercised $ 182 $ 118 $ 98 Intrinsic value of stock options exercised $ 1,057 $ 290 $ 194 Tax benefit from exercises $ 54 $ 94 $ 60
Summary of stock-based compensation	For the years ended December 31, 2015 , 2016 and 2017 , the Company recognized stock-based compensation expense as follows: Year Ended December 31, 2015 2016 2017 (In thousands) Instructional costs and services $ 1,598 $ 1,497 $ 1,310 Selling and promotional 684 672 789 General and administrative 3,630 3,042 4,147 Total stock-based compensation expense $ 5,912 $ 5,211 $ 6,246
Summary of repurchases during the period	During the year ended December 31, 2015 , the Company repurchased 1,322,846 shares of the Company’s common stock, par value $0.01 per share. The chart and footnotes below provide detail as to the Company’s repurchases during the period. Total Number of Shares Purchased Average Price Paid per Share Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs Maximum Number of Shares that May Yet Be Purchased Under the Plans or Programs (1) Maximum Number (or Approximate Dollar Value) of Shares that May Yet Be Purchased Under the Plans or Programs (2) (3) January 1, 2015 — $ — — 155,695 $ 15,027,043 January 1, 2015 - January 31, 2015 — $ — — 263,523 15,027,043 February 1, 2015 - February 28, 2015 — $ — — 263,523 15,027,043 March 1, 2015 - March 31, 2015 100,000 $ 31.69 100,000 213,523 13,442,543 April 1, 2015 - April 30, 2015 203,820 $ 30.84 203,820 147,289 9,220,841 May 1, 2015 - May 31, 2015 200,000 $ 25.59 200,000 147,289 4,102,131 June 1, 2015 - June 30, 2015 160,000 $ 24.93 160,000 164,093 15,114,029 July 1, 2015 - July 31, 2015 — $ — — 164,093 15,114,029 August 1, 2015 - August 31, 2015 — $ — — 164,093 15,114,029 September 1, 2015 - September 30, 2015 129,849 $ 23.15 129,849 164,093 12,107,835 October 1, 2015 - October 31, 2015 211,040 $ 23.19 211,040 164,562 7,214,395 November 1, 2015 - November 30, 2015 199,391 $ 22.11 199,391 164,562 2,806,575 December 1, 2015 - December 31, 2015 118,746 $ 22.39 118,746 164,562 148,008 Total 1,322,846 $ 25.34 1,322,846 164,562 $ 148,008 During the year ended December 31, 2016 , the Company did not repurchase shares of the Company’s common stock, par value $0.01 per share, other than shares deemed to have been repurchased to satisfy employee minimum tax withholding requirements in connection with the vesting of restricted stock grants. The chart and footnotes below provide detail as to the Company’s repurchases during the period. Total Number of Shares Purchased Average Price Paid per Share Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs Maximum Number of Shares that May Yet Be Purchased Under the Plans or Programs (2) Maximum Number (or Approximate Dollar Value) of Shares that May Yet Be Purchased Under the Plans or Programs (2) (3) January 1, 2016 — $ — — 164,562 $ 148,008 January 1, 2016 – January 31, 2016 — — — 480,645 148,008 February 1, 2016 – February 29, 2016 — — — 480,645 148,008 March 1, 2016 – March 31, 2016 — — — 480,645 148,008 April 1, 2016 – April 30, 2016 — — — 481,497 148,008 May 1, 2016 – May 31, 2016 — — — 481,497 148,008 June 1, 2016 – June 30, 2016 — — — 495,378 148,008 July 1, 2016 – July 31, 2016 — — — 500,687 148,008 August 1, 2016 – August 31, 2016 — — — 500,687 148,008 September 1, 2016 – September 30, 2016 — — — 500,687 148,008 October 1, 2016 – October 31, 2016 — — — 500,996 148,008 November 1, 2016 – November 30, 2016 — — — 500,996 148,008 December 1, 2016 – December 31, 2016 — — — 500,996 148,008 Total — — — 500,996 $ 148,008 During the year ended December 31, 2017 , the Company did not repurchase shares of the Company’ s common stock, par value $0.01 per share, other than shares deemed to have been repurchased to satisfy employee minimum tax withholding requirements in connection with the vesting of restricted stock grants. The chart and footnotes below provide detail as to the Company’s repurchases during the period. Total Number of Shares Purchased Average Price Paid per Share Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs Maximum Number of Shares that May Yet Be Purchased Under the Plans or Programs (2) Maximum Number (or Approximate Dollar Value) of Shares that May Yet Be Purchased Under the Plans or Programs (2) (3) January 1, 2017 — $ — — 500,996 $ 148,008 January 1, 2017 – January 31, 2017 — — — 744,718 148,008 February 1, 2017 – February 28, 2017 — — — 744,718 148,008 March 1, 2017 – March 31, 2017 — — — 744,718 148,008 April 1, 2017 – April 30, 2017 — — — 745,782 148,008 May 1, 2017 – May 31, 2017 — — — 757,398 148,008 June 1, 2017 – June 30, 2017 — — — 779,133 148,008 July 1, 2017 – July 31, 2017 — — — 779,930 148,008 August 1, 2017 – August 31, 2017 — — — 779,930 148,008 September 1, 2017 – September 30, 2017 — — — 779,930 148,008 October 1, 2017 – October 31, 2017 — — — 780,725 148,008 November 1, 2017 – November 30, 2017 — — — 780,725 148,008 December 1, 2017 – December 31, 2017 — — — 780,725 148,008 Total — — — 780,725 $ 148,008 (1) On December 9, 2011, the Company’s Board of Directors approved a stock repurchase program for its common stock, under which the Company may annually purchase up to the cumulative number of shares issued or deemed issued in that year under the Company’s equity incentive and stock purchase plans. Repurchases may be made from time to time in the open market at prevailing market prices or in privately negotiated transactions based on business and market conditions. The stock repurchase program does not obligate us to repurchase any shares, may be suspended or discontinued at any time, and is funded using the Company’s available cash. (2) On May 14, 2012, the Company’s Board of Directors authorized a program to repurchase up to $20 million of shares of the Company’s common stock. On each of March 14, 2013, June 13, 2014, and June 12, 2015 the Company’s Board of Directors increased the authorization by an additional $15 million of shares, for a cumulative increase of $45 million of shares and a total authorization of $65 million of shares. Subject to market conditions, applicable legal requirements and other factors, the repurchases may be made from time to time in the open market or privately negotiated transactions. The authorization does not obligate the Company to acquire any shares, and purchases may be commenced or suspended at any time based on market conditions and other factors as the Company deems appropriate. (3) The Company was deemed to have repurchased 49,512 and 68,065 shares of common stock forfeited by employees to satisfy minimum tax-withholding requirements in connection with the vesting of restricted stock grants during the years ended December 31, 2016 and 2017 , respectively. During the year ended December 31, 2015, the Company was deemed to have repurchased 56,272 shares of common stock forfeited by employees to satisfy minimum tax withholding requirements in connect with the vesting of restricted stock grants and to cover the exercise and minimum tax-withholding requirements of expiring stock options. These repurchases were not part of the stock repurchase program authorized by the Company’s Board of Directors.

Concentration (Tables)

Concentration (Tables)	12 Months Ended
	Dec. 31, 2017
Risks and Uncertainties [Abstract]
Summary of APEI segment revenues	A summary of APEI Segment revenue derived from students by primary funding source for the years ended December 31, 2015 , 2016 and 2017 is as follows: Year Ended December 31, 2015 2016 2017 DoD tuition assistance programs 35% 36% 37% Title IV programs 32% 29% 27% VA education benefits 21% 22% 23% Cash and other sources 12% 13% 13% A summary of HCN Segment revenue derived from students by primary funding source for the years ended December 31, 2015 , 2016 and 2017 is as follows: Year Ended December 31, 2015 2016 2017 Title IV programs 86% 84% 83% Cash and other sources 11% 13% 14% VA education benefits 2% 3% 2%

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Summary of financial information by reportable segment	A summary of financial information by reportable segment is as follows (in thousands): Year Ended December 31, 2015 2016 2017 Revenue American Public Education Segment $ 297,439 $ 283,941 $ 265,246 Hondros College of Nursing Segment 30,471 29,198 34,002 Total Revenue $ 327,910 $ 313,139 $ 299,248 Depreciation and Amortization American Public Education Segment $ 19,337 $ 18,029 $ 17,376 Hondros College of Nursing Segment 1,183 1,355 1,400 Total Depreciation and Amortization $ 20,520 $ 19,384 $ 18,776 Income from operations before interest income and income taxes American Public Education Segment $ 48,967 $ 41,916 $ 30,873 Hondros College of Nursing Segment 3,314 (3,640 ) 3,986 Total income from operations before interest income and income taxes $ 52,281 $ 38,276 $ 34,859 Interest Income, Net American Public Education Segment $ 115 $ 116 $ 185 Hondros College of Nursing Segment — — — Total Interest Income, Net $ 115 $ 116 $ 185 Income Tax Expense American Public Education Segment $ 18,788 $ 16,322 $ 10,289 Hondros College of Nursing Segment 1,284 (1,382 ) 1,204 Total Income Tax Expense $ 20,072 $ 14,940 $ 11,493 Capital Expenditures American Public Education Segment $ 24,541 $ 12,912 $ 10,414 Hondros College of Nursing Segment 1,461 914 441 Total Capital Expenditures $ 26,002 $ 13,826 $ 10,855
Summary of consolidated assets by reportable segment	A summary of the Company’s consolidated assets by reportable segment is as follows (in thousands): As of December 31, 2016 2017 Assets American Public Education Segment $ 267,260 $ 287,656 Hondros College of Nursing Segment 48,360 51,382 Total Assets $ 315,620 $ 339,038

Quarterly Financial Summary (35

Quarterly Financial Summary (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of unaudited quarterly financial information	The following tables set forth selected unaudited quarterly financial information for each of the Company’s last eight quarters: 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter (in thousands, except per share data) 2017 Revenue $ 75,688 $ 72,196 $ 73,279 $ 78,085 Income from operations before income taxes 8,318 6,333 7,616 12,777 Net income 4,509 3,829 4,366 8,417 Net income per common share: Basic $ 0.28 $ 0.24 $ 0.27 $ 0.52 Diluted $ 0.28 $ 0.23 $ 0.27 $ 0.51 2016 Revenue $ 83,966 $ 76,745 $ 73,803 $ 78,625 Income from operations before income taxes 16,007 10,697 429 11,259 Net income 10,340 6,596 326 6,893 Net income per common share: Basic $ 0.64 $ 0.41 $ 0.02 $ 0.43 Diluted $ 0.64 $ 0.41 $ 0.02 $ 0.42

Nature of Business (Details)

Nature of Business (Details) Person in Thousands	12 Months Ended
	Dec. 31, 2017subsidiaryCampusPersonsegment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of students | Person	86
Number of subsidiary institutions | subsidiary	2
Number of campuses | Campus	5
Number of reportable segments | segment	2

Significant Accounting Polici37

Significant Accounting Policies - Restricted Cash (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Restricted cash	$ 2.3	$ 1.6

Significant Accounting Polici38

Significant Accounting Policies - Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2017
Software development
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	5 years
Program development
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	3 years
Program development | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	3 years

Significant Accounting Polici39

Significant Accounting Policies - Goodwill and indefinite-lived intangible assets (Details) - USD ($)	1 Months Ended	12 Months Ended
	Aug. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Nov. 01, 2013
Business Acquisition [Line Items]
Goodwill acquired		$ 33,899,000	$ 33,899,000	$ 38,634,000
Impairment of goodwill	$ 4,700,000	0	$ 4,735,000	$ 0
HCN
Business Acquisition [Line Items]
Goodwill acquired					$ 38,600,000
Indefinite-lived intangible assets acquired					$ 3,700,000
Impairment of goodwill		$ 4,700,000

Significant Accounting Polici40

Significant Accounting Policies - Revenue Recognition (Details)	12 Months Ended
	Dec. 31, 2017
Deferred Revenue Arrangement [Line Items]
Percentage of refund of tuition before the conclusion of the first seven days of a course	100.00%
Minimum
Deferred Revenue Arrangement [Line Items]
Period of revenue recognition	56 days
Maximum
Deferred Revenue Arrangement [Line Items]
Period of revenue recognition	112 days

Significant Accounting Polici41

Significant Accounting Policies - American Public University System Tuition Refund Schedule (Details)	12 Months Ended
	Dec. 31, 2017
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Tuition refund percentage before or during week 1	100.00%
Eight Week Course
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Tuition refund percentage before or during week 1	100.00%
Tuition refund percentage during week 2	75.00%
Tuition refund percentage during weeks 3 and 4	50.00%
Tuition refund percentage during weeks 5 through 8	0.00%
Sixteen Week Course
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Tuition refund percentage before or during week 1	100.00%
Tuition refund percentage during week 2	100.00%
Tuition refund percentage during weeks 3 and 4	75.00%
Tuition refund percentage during weeks 5 through 8	50.00%
Tuition refund percentage during weeks 9 through 16	0.00%

Significant Accounting Polici42

Significant Accounting Policies - Hondros College of Nursing Refund Schedule (Details)	12 Months Ended
	Dec. 31, 2017
Full Calendar Week
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Tuition refund percentage before full calendar week	100.00%
During Full Calendar Week
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Tuition refund percentage	75.00%
During Second Calendar Week
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Tuition refund percentage	50.00%
During Third Full Calendar Week
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Tuition refund percentage	25.00%
During Fourth Full Calendar Week
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Tuition refund percentage	0.00%

Significant Accounting Polici43

Significant Accounting Policies - Deferred Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred Revenue Arrangement [Line Items]
Deferred revenue	$ 19,374	$ 20,639
Sales Revenue, Services, Net
Deferred Revenue Arrangement [Line Items]
Scholarship assistance	17,851	18,021	$ 7,583
Student deposits
Deferred Revenue Arrangement [Line Items]
Deferred revenue	$ 9,129	$ 9,158

Significant Accounting Polici44

Significant Accounting Policies - Advertising Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Selling and promotional
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Advertising expenses	$ 39,829	$ 39,450	$ 42,226

Significant Accounting Polici45

Significant Accounting Policies - Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Reduction in income tax expense related to Tax Cuts and Jobs Act of 2017	$ 3,741,000	$ 0	$ 0

Significant Accounting Polici46

Significant Accounting Policies - Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adjustment of retained earnings		$ (108,569)	$ (87,448)
Income tax expense		11,493	14,940	$ 20,072
Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Graduation fee revenue		1,100
Revenue, performance obligation not satisfied		400
Adjustment of retained earnings		400
Accounting Standards Update 2015-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred tax asset, current			5,100
Deferred tax liabilities, noncurrent			$ 13,900
Accounting Standards Update 2016-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax expense		$ 500
Accounting Standards Update 2016-09 | Minimum | Scenario, Forecast
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax expense	$ 200
Accounting Standards Update 2016-09 | Maximum | Scenario, Forecast
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax expense	$ 400

Acquisition Accounting - Narrat

Acquisition Accounting - Narrative (Details) - USD ($) $ in Thousands	Dec. 30, 2014	Nov. 01, 2013	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Aggregate purchase price			$ 46,764
Goodwill		$ 38,100
Fair value of IRC 338(h)(10) election			$ 636
HCN
Business Acquisition [Line Items]
Aggregate purchase price		46,300		$ 46,800
Goodwill				$ 38,600
Fair value of IRC 338(h)(10) election		$ 150
Revised estimate of fair value of liability	$ 636

Acquisition Accounting - Schedu

Acquisition Accounting - Schedule of Fair Value of Identified Intangible Assets Acquired (Details) - USD ($) $ in Thousands	Nov. 01, 2013	Dec. 31, 2017
Fair value consideration transferred:
Cash		$ 46,128
Fair Value of IRC 338(h)(10) election		636
Total fair value consideration transferred		46,764
Recognized amounts of identifiable tangible assets acquired and liabilities assumed:
Assets acquired		4,834
Liabilities assumed		4,786
Assets acquired in excess of liabilities assumed		48
Recognized identified intangible assets:
Total recognized identified intangible assets		8,082
Goodwill		38,634
Trade name
Recognized identified intangible assets:
Total recognized identified intangible assets		1,998
Accreditation, licensing and Title IV
Recognized identified intangible assets:
Total recognized identified intangible assets		1,686
Affiliate agreements
Recognized identified intangible assets:
Total recognized identified intangible assets		37
Student contracts and relationships
Recognized identified intangible assets:
Total recognized identified intangible assets		$ 3,870
Useful Life	6 years	6 years
Curricula
Recognized identified intangible assets:
Total recognized identified intangible assets		$ 405
Useful Life	3 years	3 years
Non-compete agreements
Recognized identified intangible assets:
Total recognized identified intangible assets		$ 86
Useful Life	5 years	5 years

Property and Equipment - Schedu

Property and Equipment - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 191,551	$ 184,436
Accumulated depreciation and amortization	99,177	86,749
Property and equipment, net	92,374	97,687
Land
Property, Plant and Equipment [Line Items]
Property and equipment, gross	9,244	9,244
Building and building improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 54,408	54,691
Building and building improvements | Minimum
Property, Plant and Equipment [Line Items]
Useful Life	27 years 6 months
Building and building improvements | Maximum
Property, Plant and Equipment [Line Items]
Useful Life	39 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,437	1,208
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Useful Life	15 years
Office equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 2,248	2,219
Useful Life	5 years
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 22,736	22,492
Useful Life	3 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 8,022	8,036
Useful Life	7 years
Other capital assets
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 128	128
Useful Life	5 years
Software development
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 84,178	79,452
Useful Life	5 years
Program development
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 9,150	$ 6,966
Useful Life	3 years
Program development | Maximum
Property, Plant and Equipment [Line Items]
Useful Life	3 years

Property and Equipment - Narrat

Property and Equipment - Narrative (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Assets held for sale	$ 0	$ 2,100
Property and equipment, net	92,374	97,687
Loss on disposals of long-lived assets	2,093	5,970	$ 817
Depreciation expense	18,178	18,674	19,626
Amortization expense related to other assets	$ 598	710	$ 894
Software development | APEI Segment
Property, Plant and Equipment [Line Items]
Property and equipment, net		4,000
Incurred cost of long-lived assets disposed		$ 4,000

Assets Held For Sale (Details)

Assets Held For Sale (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on disposals of long-lived assets	$ 2,093	$ 5,970	$ 817
APEI Segment | Disposal group, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on assets held for sale	600	800
Real property one | Charles Town, West Virginia | APEI Segment | Disposal group, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Fair value of assets held for sale	2,100	2,100
Loss on assets held for sale		500
Net sale price	1,500
Loss on disposals of long-lived assets	$ 600
Real property two | Charles Town, West Virginia | APEI Segment | Disposal group, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal group assets		1,100
Net sale price		800
Loss on disposals of long-lived assets		$ 300

Investments (Details)

Investments (Details) - USD ($) $ in Thousands	Feb. 01, 2016	Dec. 21, 2015	Apr. 02, 2014	Feb. 20, 2013	Sep. 30, 2012	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Payments to acquire equity method investments						$ 300	$ 950	$ 3,871
Cost method investments, non-cash impairment						300
Cost method investments						$ 3,800	3,800
NWHW holdings
Schedule of Equity Method Investments [Line Items]
Payments to acquire equity method investments					$ 6,800
Percentage of fully diluted equity					20.00%
Proceeds from equity method investment, dividends							$ 3,000
Fidelis Education
Schedule of Equity Method Investments [Line Items]
Payments to acquire equity method investments	$ 950			$ 4,000
Percentage of fully diluted equity				22.00%		23.00%
Equity method investment, non-cash impairment						$ 2,200
Second Avenue Software
Schedule of Equity Method Investments [Line Items]
Payments to acquire equity method investments			$ 1,500
Percentage of fully diluted equity			26.00%
Equity method investment, non-cash impairment						$ 200
RallyPoint
Schedule of Equity Method Investments [Line Items]
Payments to acquire equity method investments		$ 3,500
Percentage of fully diluted equity		14.00%

Goodwill and Intangible Asset53

Goodwill and Intangible Assets - Narrative (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Aug. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Nov. 01, 2013
Business Acquisition [Line Items]
Goodwill		$ 33,899,000	$ 33,899,000	$ 38,634,000
Other identifiable intangible assets		8,082,000
Identified intangible assets with indefinite useful life		3,721,000	3,721,000
Impairment of goodwill	$ 4,700,000	0	$ 4,735,000	$ 0
Impairment of intangible assets		0
HCN
Business Acquisition [Line Items]
Goodwill					$ 38,600,000
Other identifiable intangible assets					8,100,000
Identified intangible assets with indefinite useful life					3,700,000
Identified intangible assets with finite useful life					$ 4,400,000
Fair value of goodwill		33,900,000
Impairment of goodwill		$ 4,700,000

Goodwill and Intangible Asset54

Goodwill and Intangible Assets - Schedule of Identified Intangible Assets with Definite Life (Details)	Nov. 01, 2013	Dec. 31, 2017
Student contracts and relationships
Finite-Lived Intangible Assets [Line Items]
Useful Life	6 years	6 years
Curricula
Finite-Lived Intangible Assets [Line Items]
Useful Life	3 years	3 years
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Useful Life	5 years	5 years

Goodwill and Intangible Asset55

Goodwill and Intangible Assets - Schedule of Future Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
2,018	$ 563
2,019	322
2020 and beyond	0
Net Carrying Amount	$ 885	$ 1,483

Goodwill and Intangible Asset56

Goodwill and Intangible Assets - Schedule of Changes in Carrying Amount of Goodwill by Reportable Segment (Details) - USD ($)	1 Months Ended	12 Months Ended
	Aug. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Roll Forward]
Beginning balance		$ 33,899,000	$ 38,634,000
Impairment	$ (4,700,000)	0	(4,735,000)	$ 0
Ending balance		33,899,000	33,899,000	38,634,000
APEI Segment
Goodwill [Roll Forward]
Beginning balance		0	0
Impairment		0	0
Ending balance		0	0	0
HCN Segment
Goodwill [Roll Forward]
Beginning balance		33,899,000	38,634,000
Impairment		0	(4,735,000)
Ending balance		$ 33,899,000	$ 33,899,000	$ 38,634,000

Goodwill and Intangible Asset57

Goodwill and Intangible Assets - Schedule of Components of Net Carrying Amount of Goodwill by Reportable Segment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount of goodwill, ending balance	$ 33,899	$ 38,634
Accumulated impairment	0	(4,735)
Net Carrying amount of goodwill, ending balance	33,899	33,899	$ 38,634
APEI Segment
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount of goodwill, ending balance	0	0
Accumulated impairment	0	0
Net Carrying amount of goodwill, ending balance	0	0	0
HCN Segment
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount of goodwill, ending balance	33,899	38,634
Accumulated impairment	0	(4,735)
Net Carrying amount of goodwill, ending balance	$ 33,899	$ 33,899	$ 38,634

Goodwill and Intangible Asset58

Goodwill and Intangible Assets - Schedule of Other Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Finite-lived intangible assets
Gross Carrying Amount	$ 4,361	$ 4,361
Accumulated Amortization	3,476	2,878
Net Carrying Amount	885	1,483
Indefinite-lived intangible assets
Gross Carrying Amount	3,721	3,721
Net Carrying Amount	3,721	3,721
Total intangible assets gross carrying amount	8,082	8,082
Total intangible assets net carrying amount	4,606	5,204
Trade name
Indefinite-lived intangible assets
Gross Carrying Amount	1,998	1,998
Net Carrying Amount	1,998	1,998
Accreditation, licensing and Title IV
Indefinite-lived intangible assets
Gross Carrying Amount	1,686	1,686
Net Carrying Amount	1,686	1,686
Affiliation agreements
Indefinite-lived intangible assets
Gross Carrying Amount	37	37
Net Carrying Amount	37	37
Curricula
Finite-lived intangible assets
Gross Carrying Amount	405	405
Accumulated Amortization	405	405
Net Carrying Amount	0	0
Non-compete agreements
Finite-lived intangible assets
Gross Carrying Amount	86	86
Accumulated Amortization	72	54
Net Carrying Amount	14	32
Student contracts and relationships
Finite-lived intangible assets
Gross Carrying Amount	3,870	3,870
Accumulated Amortization	2,999	2,419
Net Carrying Amount	$ 871	$ 1,451

Operating Leases - Narrative (D

Operating Leases - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Campus	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Property, Plant and Equipment [Line Items]
Number of campuses | Campus	5
APEI Segment
Property, Plant and Equipment [Line Items]
Rent expense | $	$ 677	$ 584	$ 1,094
HCN Segment
Property, Plant and Equipment [Line Items]
Number of campuses | Campus	5
Rent expense | $	$ 2,729	$ 2,528	$ 2,347

Operating Leases - Schedule of

Operating Leases - Schedule of Minimum Rental Commitment Due Under Operating Lease (Details) $ in Thousands	Dec. 31, 2017USD ($)
Leases [Abstract]
2,018	$ 2,380
2,019	2,350
2,020	2,406
2,021	2,424
2,022	2,366
2023 and beyond	4,236
Total minimum rental commitment	$ 16,162

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current income tax expense:
Federal	$ 11,989	$ 13,518	$ 17,910
State	1,998	1,877	2,322
Current income tax expense	13,987	15,395	20,232
Deferred tax expense:
Federal	(2,810)	(424)	(241)
State	316	(31)	81
Deferred tax expense	(2,494)	(455)	(160)
Income Tax Expense	$ 11,493	$ 14,940	$ 20,072

Income Taxes - Schedule of Tax

Income Taxes - Schedule of Tax Effects of Principal Temporary Differences (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets
Stock option compensation expense	$ 415	$ 1,057
Allowance for doubtful accounts	1,569	3,079
Accrued vacation and severance	679	798
Deferred rent	67	0
Restricted stock	922	1,874
Investment	0	168
Total deferred tax assets	3,652	6,976
Deferred tax liabilities
Income tax deductible capitalized software development costs	(6,066)	(10,886)
Goodwill	(1,284)	(941)
Property and equipment	(1,489)	(2,208)
Prepaid expenses	(1,017)	(1,716)
Investment	(77)	0
Total deferred tax liabilities	(9,933)	(15,751)
Deferred tax liabilities, net	$ (6,281)	$ (8,775)

Income Taxes - Schedule of Diff

Income Taxes - Schedule of Difference of Income Tax Expense from the United States Federal Income Tax Rates (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Amount
Tax expense at statutory rate	$ 11,415,000	$ 13,683,000	$ 18,370,000
State taxes, net	1,626,000	1,278,000	1,590,000
Permanent differences	2,060,000	221,000	278,000
Change in statutory rate	(3,741,000)	0	0
Other	133,000	(242,000)	(166,000)
Income Tax Expense	$ 11,493,000	$ 14,940,000	$ 20,072,000
Percentage
Tax expense at statutory rate (as a percent)	35.00%	35.00%	35.00%
State taxes, net (as a percent)	4.98%	3.27%	3.03%
Permanent differences (as a percent)	6.31%	0.56%	0.53%
Change in statutory rate (as a percent)	(11.47%)	0.00%	0.00%
Other (as a percent)	0.42%	(0.62%)	(0.32%)
Total percentage	35.24%	38.21%	38.24%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
Tax benefit related to revaluation of its net deferred tax liabilities, Tax Cuts and Jobs Act of 2017		$ 3.7
Effective income tax rate		35.00%	35.00%	35.00%
Minimum | Scenario, Forecast
Income Tax Contingency [Line Items]
Effective income tax rate	27.00%
Maximum | Scenario, Forecast
Income Tax Contingency [Line Items]
Effective income tax rate	29.00%

Other Employee Benefits - Narra

Other Employee Benefits - Narrative (Details) - USD ($)	Jun. 13, 2014	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of gross annual earnings (up to)		60.00%
Percentage vested in salary reduction contributions		100.00%
Discretionary contributions		$ 3,824,000	$ 3,284,000	$ 3,309,000
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Payroll deduction period (up to)		5 days
Percentage of fair market value		85.00%
Threshold amount of total amount of contributions		$ 21,000
Threshold amount of common stock		$ 25,000
Shares of common stock available		100,000
Common stock available for issuance (in shares)	100,000

Other Employee Benefits - Sched

Other Employee Benefits - Schedule of Shares Purchased in Open Market for Employees (Details) - USD ($)	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense													$ 6,246,000	$ 5,211,000	$ 5,912,000
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares	3,065	4,613	3,535	4,161	3,717	4,991	3,617	4,617	6,822	4,939	5,443	4,322	15,374	16,942	21,526
Common Stock Fair Value (usd per share)	$ 25.80	$ 21.15	$ 23.65	$ 22.90	$ 24.80	$ 19.81	$ 28.10	$ 20.63	$ 18.61	$ 23.45	$ 25.72	$ 29.98	$ 23.13	$ 22.90	$ 23.80
Purchase Price (usd per share)	$ 21.93	$ 17.98	$ 20.10	$ 19.47	$ 21.08	$ 16.84	$ 23.89	$ 17.54	$ 15.82	$ 19.93	$ 21.86	$ 25.49	$ 19.66	$ 19.46	$ 20.02
Compensation Expense	$ 11,862	$ 14,623	$ 12,540	$ 14,293	$ 13,827	$ 14,823	$ 15,228	$ 14,287	$ 19,033	$ 17,385	$ 21,010	$ 19,406	$ 53,318	$ 58,165	$ 76,834

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details) - USD ($)	Jan. 01, 2017	Jan. 01, 2016	Jan. 01, 2015	Dec. 31, 2017	Nov. 30, 2017	Oct. 31, 2017	Sep. 30, 2017	Aug. 31, 2017	Jul. 31, 2017	Jun. 30, 2017	May 31, 2017	Apr. 30, 2017	Mar. 31, 2017	Feb. 28, 2017	Jan. 31, 2017	Dec. 31, 2016	Nov. 30, 2016	Oct. 31, 2016	Sep. 30, 2016	Aug. 31, 2016	Jul. 31, 2016	Jun. 30, 2016	May 31, 2016	Apr. 30, 2016	Mar. 31, 2016	Feb. 29, 2016	Jan. 31, 2016	Dec. 31, 2015	Nov. 30, 2015	Oct. 31, 2015	Sep. 30, 2015	Aug. 31, 2015	Jul. 31, 2015	Jun. 30, 2015	May 31, 2015	Apr. 30, 2015	Mar. 31, 2015	Feb. 28, 2015	Jan. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Jun. 12, 2015	Dec. 31, 2014	Jun. 13, 2014	Mar. 14, 2013	May 14, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)																																								0	0	0	0
Total income tax benefit																																								$ 2,473,000	$ 2,064,000	$ 2,467,000
Shares subject to outstanding awards				109,616												259,969												329,872												109,616	259,969	329,872	109,616		434,401
Par value (in dollars per share)				$ 0.01												$ 0.01												$ 0.01												$ 0.01	$ 0.01	$ 0.01	$ 0.01
Repurchase amount (up to)																																												$ 65,000,000				$ 20,000,000
Increase in authorization amount																																												15,000,000		$ 15,000,000	$ 15,000,000
Cumulative increase																																												$ 45,000,000
Shares of common stock repurchased	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	118,746	199,391	211,040	129,849	0	0	160,000	200,000	203,820	100,000	0	0	0	0	1,322,846
Shares of common stock repurchased and retired	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	118,746	199,391	211,040	129,849	0	0	160,000	200,000	203,820	100,000	0	0	0	0	1,322,846
Common Stock Forfeited for Tax Withholding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock repurchased																																								68,065	49,512	56,272
Restricted Stock and Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation expense				$ 4,500,000																																				$ 4,500,000			$ 4,500,000
Weighted average period																																								1 year 8 months
Shares forfeited																																								43,454	31,370	22,066
Dollar amount for shares forfeited																																								$ 914,272	$ 611,335	$ 815,886
Restricted Stock and Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Anti-dilutive securities (in shares)																																								0
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Anti-dilutive securities (in shares)																																								123,267	247,993	317,961
2017 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized to grant (up to)													1,675,000
Shares subject to outstanding awards				30,246																																				30,246			30,246
2011 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares subject to outstanding awards				431,016																																				431,016			431,016
2002 Stock Plan and 2007 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares subject to outstanding awards				109,616																																				109,616			109,616
Minimum | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period																																								3 years
Award expiration period																																								7 years
Maximum | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period																																								5 years
Award expiration period																																								10 years

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Restricted Stock and Restricted Stock Units Activity (Details) - Restricted Stock and Restricted Stock Units - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Number of Shares
Beginning balance (in shares)	437,971	293,419	360,769
Shares granted	279,729	336,434	127,469
Vested shares	(212,984)	(152,714)	(164,144)
Shares forfeited	(43,454)	(39,168)	(30,675)
Ending balance (in shares)	461,262	437,971	293,419
Weighted Average Grant Price and Fair Value
Beginning balance (in dollars per share)	$ 21.54	$ 35.86	$ 37.03
Shares granted (in dollars per share)	23.35	16.34	35.15
Vested shares (in dollars per share)	25.98	35.83	37.85
Shares forfeited (in dollars per share)	21.04	25.46	36.76
Ending balance (in dollars per share)	$ 20.91	$ 21.54	$ 35.86

Stockholders' Equity - Summar69

Stockholders' Equity - Summary of Status of Stock Incentive Plans and Changes During Periods (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended			84 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017
Number of Options
Beginning balance (in shares)	259,969	329,872	434,401
Options granted (in shares)	0	0	0	0
Awards exercised (in shares)	(14,002)	(16,878)	(55,382)
Options forfeited (in shares)	(136,351)	(53,024)	(49,147)
Ending balance (in shares)	109,616	259,969	329,872	109,616
Number of options exercisable (in shares)	109,616	259,969	329,872	109,616
Weighted Average Exercise Price
Beginning balance (in dollars per share)	$ 34.68	$ 33.65	$ 30.04
Options granted (in dollars per share)	0	0	0
Awards exercised (in dollars per share)	6.99	7	3.29
Options forfeited (in dollars per share)	35.24	37.09	35.97
Ending balance (in dollars per share)	37.52	34.68	33.65	$ 37.52
Weighted average exercise price exercisable (in dollars per share)	$ 37.52	$ 34.68	$ 33.65	$ 37.52
Weighted Average Contractual Life and Aggregate Intrinsic Value
Weighted average contractual life outstanding	5 days	6 months 10 days	1 year 3 months 20 days
Weighted average contractual life exercisable	5 days	6 months 10 days	1 year 3 months 20 days
Aggregate intrinsic value outstanding	$ 0	$ 246	$ 359	$ 0
Aggregate intrinsic value exercisable	$ 0	$ 246	$ 359	$ 0

Stockholders' Equity - Summar70

Stockholders' Equity - Summary of Information Regarding Stock Option Exercises (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Equity [Abstract]
Cash received from issuance of common stock	$ 98	$ 118	$ 182
Intrinsic value of stock options exercised	194	290	1,057
Tax benefit from exercises	$ 60	$ 94	$ 54

Stockholders' Equity - Summar71

Stockholders' Equity - Summary of Stock-based Compensation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total stock-based compensation expense	$ 6,246	$ 5,211	$ 5,912
Instructional costs and services
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total stock-based compensation expense	1,310	1,497	1,598
Selling and promotional
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total stock-based compensation expense	789	672	684
General and administrative
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total stock-based compensation expense	$ 4,147	$ 3,042	$ 3,630

Stockholders' Equity - Summar72

Stockholders' Equity - Summary of Repurchases During the Period (Details) - USD ($)	Jan. 01, 2017	Jan. 01, 2016	Jan. 01, 2015	Dec. 31, 2017	Nov. 30, 2017	Oct. 31, 2017	Sep. 30, 2017	Aug. 31, 2017	Jul. 31, 2017	Jun. 30, 2017	May 31, 2017	Apr. 30, 2017	Mar. 31, 2017	Feb. 28, 2017	Jan. 31, 2017	Dec. 31, 2016	Nov. 30, 2016	Oct. 31, 2016	Sep. 30, 2016	Aug. 31, 2016	Jul. 31, 2016	Jun. 30, 2016	May 31, 2016	Apr. 30, 2016	Mar. 31, 2016	Feb. 29, 2016	Jan. 31, 2016	Dec. 31, 2015	Nov. 30, 2015	Oct. 31, 2015	Sep. 30, 2015	Aug. 31, 2015	Jul. 31, 2015	Jun. 30, 2015	May 31, 2015	Apr. 30, 2015	Mar. 31, 2015	Feb. 28, 2015	Jan. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Equity [Abstract]
Total Number of Shares Purchased	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	118,746	199,391	211,040	129,849	0	0	160,000	200,000	203,820	100,000	0	0	0	0	1,322,846
Average Price Paid per Share (in dollars per share)	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 22.39	$ 22.11	$ 23.19	$ 23.15	$ 0	$ 0	$ 24.93	$ 25.59	$ 30.84	$ 31.69	$ 0	$ 0	$ 0	$ 0	$ 25.34
Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	118,746	199,391	211,040	129,849	0	0	160,000	200,000	203,820	100,000	0	0	0	0	1,322,846
Maximum Number of Shares that May Yet Be Purchased Under the Plans or Programs	500,996,000	164,562,000	155,695	780,725,000	780,725,000	780,725,000	779,930,000	779,930,000	779,930,000	779,133,000	757,398,000	745,782,000	744,718,000	744,718,000	744,718,000	500,996,000	500,996,000	500,996,000	500,687,000	500,687,000	500,687,000	495,378,000	481,497,000	481,497,000	480,645,000	480,645,000	480,645,000	164,562	164,562	164,562	164,093	164,093	164,093	164,093	147,289	147,289	213,523	263,523	263,523	780,725,000	500,996,000	164,562
Maximum Number (or Approximate Dollar Value) of Shares that May Yet Be Purchased Under the Plans or Programs	$ 148,008	$ 148,008	$ 15,027,043	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 148,008	$ 2,806,575	$ 7,214,395	$ 12,107,835	$ 15,114,029	$ 15,114,029	$ 15,114,029	$ 4,102,131	$ 9,220,841	$ 13,442,543	$ 15,027,043	$ 15,027,043	$ 148,008	$ 148,008	$ 148,008

Concentration - Narrative (Deta

Concentration - Narrative (Details) - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
APEI Segment | Number of Students | Military On Active Duty
Concentration Risk [Line Items]
Percentage of students	54.00%
APEI Segment | Segment Revenue | VA education benefits
Concentration Risk [Line Items]
Percentage of students	23.00%	22.00%	21.00%
HCN Segment | Segment Revenue | VA education benefits
Concentration Risk [Line Items]
Percentage of students	14.00%	13.00%	11.00%

Concentration - Summary of Segm

Concentration - Summary of Segment Revenue Derived from Students by Primary Funding Source (Details) - Segment Revenue - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
APEI Segment | DoD tuition assistance programs
Concentration Risk [Line Items]
Concentration risk percentage	37.00%	36.00%	35.00%
APEI Segment | Title IV programs
Concentration Risk [Line Items]
Concentration risk percentage	27.00%	29.00%	32.00%
APEI Segment | VA education benefits
Concentration Risk [Line Items]
Concentration risk percentage	23.00%	22.00%	21.00%
APEI Segment | Cash and other sources
Concentration Risk [Line Items]
Concentration risk percentage	13.00%	13.00%	12.00%
HCN Segment | Title IV programs
Concentration Risk [Line Items]
Concentration risk percentage	83.00%	84.00%	86.00%
HCN Segment | VA education benefits
Concentration Risk [Line Items]
Concentration risk percentage	14.00%	13.00%	11.00%
HCN Segment | Cash and other sources
Concentration Risk [Line Items]
Concentration risk percentage	2.00%	3.00%	2.00%

Segment Information - Narrative

Segment Information - Narrative (Details)	12 Months Ended
	Dec. 31, 2017segment
Segment Reporting [Abstract]
Number of operating segments	2

Segment Information - Summary o

Segment Information - Summary of Financial Information by Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue
Total Revenue	$ 78,085	$ 73,279	$ 72,196	$ 75,688	$ 78,625	$ 73,803	$ 76,745	$ 83,966	$ 299,248	$ 313,139	$ 327,910
Depreciation and Amortization
Total Depreciation and Amortization									18,776	19,384	20,520
Income from operations before interest income and income taxes
Total income from operations before interest income and income taxes									34,859	38,276	52,281
Interest Income, Net
Total Interest Income, Net									185	116	115
Income Tax Expense
Total Income Tax Expense									11,493	14,940	20,072
Capital Expenditures
Capital Expenditures									10,855	13,826	26,002
American Public Education Segment
Revenue
Total Revenue									265,246	283,941	297,439
Depreciation and Amortization
Total Depreciation and Amortization									17,376	18,029	19,337
Income from operations before interest income and income taxes
Total income from operations before interest income and income taxes									30,873	41,916	48,967
Interest Income, Net
Total Interest Income, Net									185	116	115
Income Tax Expense
Total Income Tax Expense									10,289	16,322	18,788
Capital Expenditures
Capital Expenditures									10,414	12,912	24,541
Hondros College of Nursing Segment
Revenue
Total Revenue									34,002	29,198	30,471
Depreciation and Amortization
Total Depreciation and Amortization									1,400	1,355	1,183
Income from operations before interest income and income taxes
Total income from operations before interest income and income taxes									3,986	(3,640)	3,314
Interest Income, Net
Total Interest Income, Net									0	0	0
Income Tax Expense
Total Income Tax Expense									1,204	(1,382)	1,284
Capital Expenditures
Capital Expenditures									$ 441	$ 914	$ 1,461

Segment Information - Summary77

Segment Information - Summary of Consolidated Assets by Reportable Segments (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets
Total Assets	$ 339,038	$ 315,620
American Public Education Segment
Assets
Total Assets	287,656	267,260
Hondros College of Nursing Segment
Assets
Total Assets	$ 51,382	$ 48,360

Subsequent Events Subsequent Ev

Subsequent Events Subsequent Events (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Jan. 29, 2018
Subsequent Event [Line Items]
Percentage of students sampled not returned in annual compliance audit	5.00%
Subsequent Event
Subsequent Event [Line Items]
Irrevocable letter of credit as percentage of total Title IV funds that should have been returned		25.00%
Long-term debt		$ 700,000

Quarterly Financial Summary (79

Quarterly Financial Summary (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 78,085	$ 73,279	$ 72,196	$ 75,688	$ 78,625	$ 73,803	$ 76,745	$ 83,966	$ 299,248	$ 313,139	$ 327,910
Income from operations before income taxes	12,777	7,616	6,333	8,318	11,259	429	10,697	16,007	35,044	38,392	52,396
Net income	$ 8,417	$ 4,366	$ 3,829	$ 4,509	$ 6,893	$ 326	$ 6,596	$ 10,340	$ 21,121	$ 24,155	$ 32,414
Net income per common share:
Basic (in dollars per share)	$ 0.52	$ 0.27	$ 0.24	$ 0.28	$ 0.43	$ 0.02	$ 0.41	$ 0.64	$ 1.30	$ 1.50	$ 1.94
Diluted (in dollars per share)	$ 0.51	$ 0.27	$ 0.23	$ 0.28	$ 0.42	$ 0.02	$ 0.41	$ 0.64	$ 1.29	$ 1.49	$ 1.93

Schedule II Valuation and Qua80

Schedule II Valuation and Qualifying Accounts (Details) - Allowance for receivables - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 8,077	$ 13,012	$ 10,699
Additions/ (Reductions)	4,671	6,759	12,714
Write-offs	(6,472)	(11,694)	(10,401)
Balance at end of period	6,276	8,077	13,012
American Public Education Segment
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	4,712	10,286	8,461
Additions/ (Reductions)	2,631	4,861	11,203
Write-offs	(4,090)	(10,435)	(9,378)
Balance at end of period	3,253	4,712	10,286
Hondros College of Nursing Segment
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	3,365	2,726	2,238
Additions/ (Reductions)	2,040	1,898	1,511
Write-offs	(2,382)	(1,259)	(1,023)
Balance at end of period	$ 3,023	$ 3,365	$ 2,726