Related Parties	12 Months Ended
Dec. 31, 2017
Related Party Transactions [Abstract]
Related Parties	Related Parties Transactions with Union Bank and Trust Company Union Bank and Trust Company ("Union Bank") is controlled by Farmers & Merchants Investment Inc. (“F&M”), which owns a majority of Union Bank's common stock and a minority share of Union Bank's non-voting preferred stock. Michael S. Dunlap, Executive Chairman and a member of the board of directors and a significant shareholder of the Company, along with his spouse and children, owns or controls a significant portion of the stock of F&M, and Mr. Dunlap's sister, Angela L. Muhleisen, along with her spouse and children, also owns or controls a significant portion of F&M stock. Mr. Dunlap serves as a Director and Chairman of F&M. Ms. Muhleisen serves as a Director and Chief Executive Officer of F&M and as a Director, Chairperson, President, and Chief Executive Officer of Union Bank. Union Bank is deemed to have beneficial ownership of a significant number of shares of the Company because it serves in a capacity of trustee or account manager for various trusts and accounts holding shares of the Company, and may share voting and/or investment power with respect to such shares. Mr. Dunlap and Ms. Muhleisen beneficially own a significant percent of the voting rights of the Company's outstanding common stock. The Company has entered into certain contractual arrangements with Union Bank. These transactions are summarized below. Loan Purchases On December 22, 2014, the Company entered into an agreement with Union Bank in which the Company provides marketing, origination, and loan servicing services to Union Bank related to private education loans. The Company committed to purchase, or arrange for a designee to purchase, all volume originated by Union Bank under this agreement. During 2016 and 2015, the Company purchased $29.6 million (par value) and $4.4 million (par value), respectively, of private education loans from Union Bank, pursuant to this agreement. No loans were originated under this agreement in 2017. In addition to the agreement previously discussed, during 2017, the Company also purchased $2.9 million (par value) of private education loans and $10.3 million (par value) of consumer loans from Union Bank. Loan Servicing The Company serviced $462.3 million, $483.8 million, and $563.1 million of FFELP and private education loans for Union Bank as of December 31, 2017, 2016, and 2015, respectively. Servicing revenue earned by the Company from servicing loans for Union Bank was $0.5 million, $0.6 million, and $0.5 million for the years ended December 31, 2017, 2016, and 2015, respectively. As of December 31, 2017 and 2016, accounts receivable includes approximately $42,000 and $36,000, respectively, due from Union Bank for loan servicing. Funding - Participation Agreement The Company maintains an agreement with Union Bank, as trustee for various grantor trusts, under which Union Bank has agreed to purchase from the Company participation interests in student loans (the “FFELP Participation Agreement”). The Company uses this facility as a source to fund FFELP student loans. As of December 31, 2017 and 2016, $552.6 million and $496.8 million, respectively, of loans were subject to outstanding participation interests held by Union Bank, as trustee, under this agreement. The agreement automatically renews annually and is terminable by either party upon five business days' notice. This agreement provides beneficiaries of Union Bank's grantor trusts with access to investments in interests in student loans, while providing liquidity to the Company on a short-term basis. The Company can participate loans to Union Bank to the extent of availability under the grantor trusts, up to $750 million or an amount in excess of $750 million if mutually agreed to by both parties. Loans participated under this agreement have been accounted for by the Company as loan sales. Accordingly, the participation interests sold are not included on the Company's consolidated balance sheets. Operating Cash Accounts The majority of the Company's cash operating accounts are maintained at Union Bank. The Company also invests amounts in the Short term Federal Investment Trust (“STFIT”) of the Student Loan Trust Division of Union Bank, which are included in “cash and cash equivalents - held at a related party” and “restricted cash - due to customers” on the accompanying consolidated balance sheets. As of December 31, 2017 and 2016, the Company had $115.8 million and $74.3 million, respectively, invested in the STFIT or deposited at Union Bank in operating accounts, of which $56.0 million and $12.5 million as of December 31, 2017 and 2016, respectively, represented cash collected for customers. Interest income earned by the Company on the amounts invested in the STFIT and in cash operating accounts for the years ended December 31, 2017, 2016, and 2015, was $0.9 million, $0.4 million, and $0.2 million, respectively. 529 Plan Administration Services The Company provides certain 529 Plan administration services to certain college savings plans (the “College Savings Plans”) through a contract with Union Bank, as the program manager. Union Bank is entitled to a fee as program manager pursuant to its program management agreement with the College Savings Plans. For the years ended December 31, 2017, 2016, and 2015, the Company has received fees of $2.0 million, $1.6 million, and $3.5 million, respectively, from Union Bank related to the administration services provided to the College Savings Plans. Lease Arrangements Union Bank leases approximately 4,000 square feet in the Company's corporate headquarters building. Union Bank paid the Company approximately $74,000, $73,000, and $73,000 for commercial rent and storage income during 2017, 2016, and 2015, respectively. The lease agreement expires on June 30, 2023. Other Fees Paid to Union Bank During the years ended December 31, 2017, 2016, and 2015, the Company paid Union Bank approximately $127,000, $126,000, and $111,000, respectively, in cash management fees. During the years ended December 31, 2016 and 2015, the Company paid Union Bank approximately $13,000 and $47,000, respectively, in commissions. In addition, for the year ended December 31, 2015, the Company paid Union Bank approximately $205,000 in connection with servicing opportunities for various asset classes, and $36,000 for administrative services. Other Fees Received from Union Bank During the years ended December 31, 2017, 2016, and 2015, Union Bank paid the Company approximately $219,000, $209,000, and $201,000, respectively, under an employee sharing arrangement, and during the years ended December 31, 2016 and 2015, Union Bank paid the Company approximately $10,000 and $19,000, respectively, for health and productivity services. During the year ended December 31, 2017, Union Bank paid the Company approximately $11,000 in payment processing fees (net of merchant fees of approximately $1,000). 401(k) Plan Administration Union Bank administers the Company's 401(k) defined contribution plan. Fees paid to Union Bank to administer the plan are paid by the plan participants and were approximately $241,000, $280,000, and $469,000 during the years ended December 31, 2017, 2016, and 2015, respectively. Investment Services Union Bank has established various trusts whereby Union Bank serves as trustee for the purpose of purchasing, holding, managing, and selling investments in student loan asset-backed securities. On May 9, 2011, WRCM, an SEC-registered investment advisor and a subsidiary of the Company, entered into a management agreement with Union Bank, effective as of May 1, 2011, under which WRCM performs various advisory and management services on behalf of Union Bank with respect to investments in securities by the trusts, including identifying securities for purchase or sale by the trusts. The agreement provides that Union Bank will pay to WRCM annual fees of 25 basis points on the outstanding balance of the investments in the trusts. As of December 31, 2017, the outstanding balance of investments in the trusts was $665.9 million. In addition, Union Bank will pay additional fees to WRCM of up to 50 percent of the gains from the sale of securities from the trusts or securities being called prior to the full contractual maturity. For the years ended December 31, 2017, 2016, and 2015, the Company earned $9.2 million, $4.5 million, and $2.7 million, respectively, of fees under this agreement. In January 2012 and October 2015, WRCM entered into management agreements with Union Bank under which it was designated to serve as investment advisor with respect to the assets within several trusts established by Mr. Dunlap and his spouse. In January 2016, WRCM entered into a similar management agreement with Union Bank with respect to several trusts established in December 2015 by Stephen F. Butterfield, Vice Chairman and a member of the board of directors of the Company, and his spouse. Union Bank serves as trustee for the trusts. Per the terms of the agreements, Union Bank pays WRCM five basis points of the aggregate value of the assets of the trusts as of the last day of each calendar quarter. Mr. Dunlap and his spouse contributed a total of 3,375,000 and 3,000,000 shares of the Company's Class B common stock to the trusts upon the establishment of the trusts in 2011 and 2015, respectively, and Mr. Butterfield and his spouse contributed a total of 1,200,000 shares of the Company's Class B common stock upon the establishment of the trusts in 2016. For the years ended December 31, 2017, 2016, and 2015, the Company earned approximately $161,000, $142,000, and $71,000, respectively, of fees under these agreements. As of December 31, 2017 and 2016, accounts receivable included $0.2 million and $0.8 million, respectively, due from Union Bank related to fees earned by WRCM from the investment services described above. WRCM has established private investment funds for the primary purpose of purchasing, selling, investing, and trading, directly or indirectly, in student loan asset-backed securities, and to engage in financial transactions related thereto. Mr. Dunlap, Union Financial Services, Inc., which is owned 50 percent by each Mr. Dunlap and Mr. Butterfield, Jeffrey R. Noordhoek (an executive officer of the Company), Ms. Muhleisen and her spouse, and WRCM have invested in certain of these funds. Based upon the current level of holdings by non-affiliated limited partners, the management agreements provide non-affiliated limited partners the ability to remove WRCM as manager without cause. WRCM earns 50 basis points (annually) on the outstanding balance of the investments in these funds, of which WRCM pays approximately 50 percent of such amount to Union Bank as custodian. As of December 31, 2017, the outstanding balance of investments in these funds was $149.4 million. For the years ended December 31, 2017, 2016, and 2015, the Company paid Union Bank $0.3 million, $0.4 million, and $0.4 million, respectively, as custodian. Transactions with Agile Sports Technologies, Inc. (doing business as "Hudl") David Graff, who has served on the Company's Board of Directors since May 2014, is CEO, co-founder, and a director of Hudl. On March 17, 2015 and July 7, 2017, the Company made a $40.5 million and $10.4 million preferred stock investment, respectively, in Hudl. Prior to these investments, the Company and Mr. Dunlap made separate equity investments in Hudl. The Company and Mr. Dunlap, along with his children, currently hold combined direct and indirect equity ownership interests in Hudl of 19.7% and 3.4%, respectively. The Company's and Mr. Dunlap's direct and indirect equity ownership interests in Hudl consist of preferred stock with certain liquidation preferences that are considered substantive. Accordingly, for accounting purposes, the Company's and Mr. Dunlap's equity ownership interests are not considered in-substance common stock and the Company is accounting for its equity investment in Hudl under the cost method. The Company's investment in Hudl is included in "investments and notes receivable" in the Company's consolidated balance sheet. The Company makes investments to further diversify the Company both within and outside of its historical core education-related businesses, including investments in real estate. Recent real estate investments have been focused on the development of commercial properties in the Midwest, and particularly in Lincoln, Nebraska, where the Company's headquarters are located. One investment includes the development of a building in Lincoln's Haymarket District that is the new headquarters of Hudl, in which Hudl is the primary tenant in this building. Transactions with Assurity Life Insurance Company ("Assurity") Thomas Henning, who has served on the Company's Board of Directors since 2003, is the President and Chief Executive Officer of Assurity. During the year ended December 31, 2017, Nelnet Business Solutions paid $1.5 million to Assurity for insurance premiums for insurance on certain tuition payment plans. As part of providing the tuition payment plan insurance to Nelnet Business Solutions, Assurity entered into a reinsurance agreement with the Company's insurance subsidiary, under which Assurity paid the Company's insurance subsidiary reinsurance premiums of $1.4 million in 2017, and the Company's insurance subsidiary paid claims on such reinsurance to Assurity of $0.7 million in 2017. In addition, Assurity pays Nelnet Business Solutions a partial refund annually based on claim experience, which was approximately $10,000 for the year ended December 31, 2017. During the years ended December 31, 2017, 2016, and 2015, the Company made available to its employees certain voluntary insurance products through Assurity. Premiums are paid by participants and are remitted to Assurity by the Company on behalf of the participants. The Company remitted to Assurity approximately $181,000, $166,000, and $116,000 in premiums related to these products during 2017, 2016, and 2015, respectively.

Related Parties

Transactions with Union Bank and Trust Company

Union Bank and Trust Company ("Union Bank") is controlled by Farmers & Merchants Investment Inc. (“F&M”), which owns a majority of Union Bank's common stock and a minority share of Union Bank's non-voting preferred stock. Michael S. Dunlap, Executive Chairman and a member of the board of directors and a significant shareholder of the Company, along with his spouse and children, owns or controls a significant portion of the stock of F&M, and Mr. Dunlap's sister, Angela L. Muhleisen, along with her spouse and children, also owns or controls a significant portion of F&M stock. Mr. Dunlap serves as a Director and Chairman of F&M. Ms. Muhleisen serves as a Director and Chief Executive Officer of F&M and as a Director, Chairperson, President, and Chief Executive Officer of Union Bank. Union Bank is deemed to have beneficial ownership of a significant number of shares of the Company because it serves in a capacity of trustee or account manager for various trusts and accounts holding shares of the Company, and may share voting and/or investment power with respect to such shares. Mr. Dunlap and Ms. Muhleisen beneficially own a significant percent of the voting rights of the Company's outstanding common stock.

The Company has entered into certain contractual arrangements with Union Bank. These transactions are summarized below.

Loan Purchases

On December 22, 2014, the Company entered into an agreement with Union Bank in which the Company provides marketing, origination, and loan servicing services to Union Bank related to private education loans. The Company committed to purchase, or arrange for a designee to purchase, all volume originated by Union Bank under this agreement. During 2016 and 2015, the Company purchased $29.6 million (par value) and $4.4 million (par value), respectively, of private education loans from Union Bank, pursuant to this agreement. No loans were originated under this agreement in 2017.

In addition to the agreement previously discussed, during 2017, the Company also purchased $2.9 million (par value) of private education loans and $10.3 million (par value) of consumer loans from Union Bank.

Loan Servicing

The Company serviced $462.3 million, $483.8 million, and $563.1 million of FFELP and private education loans for Union Bank as of December 31, 2017, 2016, and 2015, respectively. Servicing revenue earned by the Company from servicing loans for Union Bank was $0.5 million, $0.6 million, and $0.5 million for the years ended December 31, 2017, 2016, and 2015, respectively. As of December 31, 2017 and 2016, accounts receivable includes approximately $42,000 and $36,000, respectively, due from Union Bank for loan servicing.

Funding - Participation Agreement

The Company maintains an agreement with Union Bank, as trustee for various grantor trusts, under which Union Bank has agreed to purchase from the Company participation interests in student loans (the “FFELP Participation Agreement”). The Company uses this facility as a source to fund FFELP student loans. As of December 31, 2017 and 2016, $552.6 million and $496.8 million, respectively, of loans were subject to outstanding participation interests held by Union Bank, as trustee, under this agreement. The agreement automatically renews annually and is terminable by either party upon five business days' notice. This agreement provides beneficiaries of Union Bank's grantor trusts with access to investments in interests in student loans, while providing liquidity to the Company on a short-term basis. The Company can participate loans to Union Bank to the extent of availability under the grantor trusts, up to $750 million or an amount in excess of $750 million if mutually agreed to by both parties. Loans participated under this agreement have been accounted for by the Company as loan sales. Accordingly, the participation interests sold are not included on the Company's consolidated balance sheets.

Operating Cash Accounts

The majority of the Company's cash operating accounts are maintained at Union Bank. The Company also invests amounts in the Short term Federal Investment Trust (“STFIT”) of the Student Loan Trust Division of Union Bank, which are included in “cash and cash equivalents - held at a related party” and “restricted cash - due to customers” on the accompanying consolidated balance sheets. As of December 31, 2017 and 2016, the Company had $115.8 million and $74.3 million, respectively, invested in the STFIT or deposited at Union Bank in operating accounts, of which $56.0 million and $12.5 million as of December 31, 2017 and 2016, respectively, represented cash collected for customers. Interest income earned by the Company on the amounts invested in the STFIT and in cash operating accounts for the years ended December 31, 2017, 2016, and 2015, was $0.9 million, $0.4 million, and $0.2 million, respectively.

529 Plan Administration Services

The Company provides certain 529 Plan administration services to certain college savings plans (the “College Savings Plans”) through a contract with Union Bank, as the program manager. Union Bank is entitled to a fee as program manager pursuant to its program management agreement with the College Savings Plans. For the years ended December 31, 2017, 2016, and 2015, the Company has received fees of $2.0 million, $1.6 million, and $3.5 million, respectively, from Union Bank related to the administration services provided to the College Savings Plans.

Lease Arrangements

Union Bank leases approximately 4,000 square feet in the Company's corporate headquarters building. Union Bank paid the Company approximately $74,000, $73,000, and $73,000 for commercial rent and storage income during 2017, 2016, and 2015, respectively. The lease agreement expires on June 30, 2023.

Other Fees Paid to Union Bank

During the years ended December 31, 2017, 2016, and 2015, the Company paid Union Bank approximately $127,000, $126,000, and $111,000, respectively, in cash management fees. During the years ended December 31, 2016 and 2015, the Company paid Union Bank approximately $13,000 and $47,000, respectively, in commissions. In addition, for the year ended December 31, 2015, the Company paid Union Bank approximately $205,000 in connection with servicing opportunities for various asset classes, and $36,000 for administrative services.

Other Fees Received from Union Bank

During the years ended December 31, 2017, 2016, and 2015, Union Bank paid the Company approximately $219,000, $209,000, and $201,000, respectively, under an employee sharing arrangement, and during the years ended December 31, 2016 and 2015, Union Bank paid the Company approximately $10,000 and $19,000, respectively, for health and productivity services. During the year ended December 31, 2017, Union Bank paid the Company approximately $11,000 in payment processing fees (net of merchant fees of approximately $1,000).

401(k) Plan Administration

Union Bank administers the Company's 401(k) defined contribution plan. Fees paid to Union Bank to administer the plan are paid by the plan participants and were approximately $241,000, $280,000, and $469,000 during the years ended December 31, 2017, 2016, and 2015, respectively.

Investment Services

Union Bank has established various trusts whereby Union Bank serves as trustee for the purpose of purchasing, holding, managing, and selling investments in student loan asset-backed securities. On May 9, 2011, WRCM, an SEC-registered investment advisor and a subsidiary of the Company, entered into a management agreement with Union Bank, effective as of May 1, 2011, under which WRCM performs various advisory and management services on behalf of Union Bank with respect to investments in securities by the trusts, including identifying securities for purchase or sale by the trusts. The agreement provides that Union Bank will pay to WRCM annual fees of 25 basis points on the outstanding balance of the investments in the trusts. As of December 31, 2017, the outstanding balance of investments in the trusts was $665.9 million. In addition, Union Bank will pay additional fees to WRCM of up to 50 percent of the gains from the sale of securities from the trusts or securities being called prior to the full contractual maturity. For the years ended December 31, 2017, 2016, and 2015, the Company earned $9.2 million, $4.5 million, and $2.7 million, respectively, of fees under this agreement.

In January 2012 and October 2015, WRCM entered into management agreements with Union Bank under which it was designated to serve as investment advisor with respect to the assets within several trusts established by Mr. Dunlap and his spouse. In January 2016, WRCM entered into a similar management agreement with Union Bank with respect to several trusts established in December 2015 by Stephen F. Butterfield, Vice Chairman and a member of the board of directors of the Company, and his spouse. Union Bank serves as trustee for the trusts. Per the terms of the agreements, Union Bank pays WRCM five basis points of the aggregate value of the assets of the trusts as of the last day of each calendar quarter. Mr. Dunlap and his spouse contributed a total of 3,375,000 and 3,000,000 shares of the Company's Class B common stock to the trusts upon the establishment of the trusts in 2011 and 2015, respectively, and Mr. Butterfield and his spouse contributed a total of 1,200,000 shares of the Company's Class B common stock upon the establishment of the trusts in 2016. For the years ended December 31, 2017, 2016, and 2015, the Company earned approximately $161,000, $142,000, and $71,000, respectively, of fees under these agreements.

As of December 31, 2017 and 2016, accounts receivable included $0.2 million and $0.8 million, respectively, due from Union Bank related to fees earned by WRCM from the investment services described above.

WRCM has established private investment funds for the primary purpose of purchasing, selling, investing, and trading, directly or indirectly, in student loan asset-backed securities, and to engage in financial transactions related thereto. Mr. Dunlap, Union Financial Services, Inc., which is owned 50 percent by each Mr. Dunlap and Mr. Butterfield, Jeffrey R. Noordhoek (an executive officer of the Company), Ms. Muhleisen and her spouse, and WRCM have invested in certain of these funds. Based upon the current level of holdings by non-affiliated limited partners, the management agreements provide non-affiliated limited partners the ability to remove WRCM as manager without cause. WRCM earns 50 basis points (annually) on the outstanding balance of the investments in these funds, of which WRCM pays approximately 50 percent of such amount to Union Bank as custodian. As of December 31, 2017, the outstanding balance of investments in these funds was $149.4 million. For the years ended December 31, 2017, 2016, and 2015, the Company paid Union Bank $0.3 million, $0.4 million, and $0.4 million, respectively, as custodian.

Transactions with Agile Sports Technologies, Inc. (doing business as "Hudl")

David Graff, who has served on the Company's Board of Directors since May 2014, is CEO, co-founder, and a director of Hudl. On March 17, 2015 and July 7, 2017, the Company made a $40.5 million and $10.4 million preferred stock investment, respectively, in Hudl. Prior to these investments, the Company and Mr. Dunlap made separate equity investments in Hudl. The Company and Mr. Dunlap, along with his children, currently hold combined direct and indirect equity ownership interests in Hudl of 19.7% and 3.4%, respectively. The Company's and Mr. Dunlap's direct and indirect equity ownership interests in Hudl consist of preferred stock with certain liquidation preferences that are considered substantive. Accordingly, for accounting purposes, the Company's and Mr. Dunlap's equity ownership interests are not considered in-substance common stock and the Company is accounting for its equity investment in Hudl under the cost method. The Company's investment in Hudl is included in "investments and notes receivable" in the Company's consolidated balance sheet.

The Company makes investments to further diversify the Company both within and outside of its historical core education-related businesses, including investments in real estate. Recent real estate investments have been focused on the development of commercial properties in the Midwest, and particularly in Lincoln, Nebraska, where the Company's headquarters are located. One investment includes the development of a building in Lincoln's Haymarket District that is the new headquarters of Hudl, in which Hudl is the primary tenant in this building.

Transactions with Assurity Life Insurance Company ("Assurity")

Thomas Henning, who has served on the Company's Board of Directors since 2003, is the President and Chief Executive Officer of Assurity. During the year ended December 31, 2017, Nelnet Business Solutions paid $1.5 million to Assurity for insurance premiums for insurance on certain tuition payment plans. As part of providing the tuition payment plan insurance to Nelnet Business Solutions, Assurity entered into a reinsurance agreement with the Company's insurance subsidiary, under which Assurity paid the Company's insurance subsidiary reinsurance premiums of $1.4 million in 2017, and the Company's insurance subsidiary paid claims on such reinsurance to Assurity of $0.7 million in 2017. In addition, Assurity pays Nelnet Business Solutions a partial refund annually based on claim experience, which was approximately $10,000 for the year ended December 31, 2017.

During the years ended December 31, 2017, 2016, and 2015, the Company made available to its employees certain voluntary insurance products through Assurity. Premiums are paid by participants and are remitted to Assurity by the Company on behalf of the participants. The Company remitted to Assurity approximately $181,000, $166,000, and $116,000 in premiums related to these products during 2017, 2016, and 2015, respectively.