Relationships with The Timken Company and Related Entities	12 Months Ended
Dec. 31, 2018
Related Party Transactions [Abstract]
Relationships with The Timken Company and Related Entities	Relationships with The Timken Company and Related Entities Prior to the spinoff on June 30, 2014, TimkenSteel was managed and operated in the normal course of business with other affiliates of The Timken Company. Transactions between The Timken Company and TimkenSteel, with the exception of sale and purchase transactions and reimbursements for payments made to third-party service providers by The Timken Company on TimkenSteel’s behalf, are reflected in equity in the Consolidated Balance Sheets as net parent investment and in the Consolidated Statements of Cash Flows as a financing activity in net transfers (to)/from The Timken Company and affiliates. Transactions with Other Timken Businesses TimkenSteel sold finished goods to The Timken Company. During the years ended December 31, 2018, 2017 and 2016, revenues from related-party sales of products totaled $43.2 million or 2.7% of net sales, $48.5 million, or 3.6% of net sales, and $32.7 million or 3.8% of net sales, respectively. TimkenSteel did not purchase material from The Timken Company during the years ending December 31, 2018, 2017 and 2016. In addition, certain of TimkenSteel’s third-party service providers were paid by The Timken Company on behalf of TimkenSteel. TimkenSteel would subsequently reimburse The Timken Company in cash for such payments. Material Agreements Between TimkenSteel and The Timken Company On June 30, 2014, TimkenSteel entered into a separation and distribution agreement and several other agreements with The Timken Company to affect the spinoff and to provide a framework for the relationship with The Timken Company. These agreements govern the relationship between TimkenSteel and The Timken Company subsequent to the completion of the spinoff and provide for the allocation between TimkenSteel and The Timken Company of assets, liabilities and obligations attributable to periods prior to the spinoff. Because these agreements were entered into in the context of a related party transaction, the terms may not be comparable to terms that would be obtained in a transaction between unaffiliated parties. Separation and Distribution Agreement — The separation and distribution agreement contains the key provisions relating to the spinoff, including provisions relating to the principal intercompany transactions required to effect the spinoff, the conditions to the spinoff and provisions governing the relationships between TimkenSteel and The Timken Company after the spinoff. Tax Sharing Agreement — The tax sharing agreement generally governs TimkenSteel’s and The Timken Company’s respective rights, responsibilities and obligations after the spinoff with respect to taxes for any tax period ending on or before the distribution date, as well as tax periods beginning before and ending after the distribution date. Generally, TimkenSteel is liable for all pre-distribution U.S. federal income taxes, foreign income taxes and non-income taxes attributable to TimkenSteel’s business, and all other taxes attributable to TimkenSteel, paid after the distribution. In addition, the tax sharing agreement addresses the allocation of liability for taxes that are incurred as a result of restructuring activities undertaken to effectuate the distribution. The tax sharing agreement also provides that TimkenSteel is liable for taxes incurred by The Timken Company that arise as a result of TimkenSteel’s taking or failing to take, as the case may be, certain actions that result in the distribution failing to meet the requirements of a tax-free distribution under Section 355 of the Internal Revenue Code of 1986, as amended. Employee Matters Agreement — TimkenSteel entered into an employee matters agreement with The Timken Company, which generally provides that TimkenSteel and The Timken Company each has responsibility for its own employees and compensation plans, subject to certain exceptions as described in the agreement. In general, prior to the spinoff, TimkenSteel employees participated in various retirement, health and welfare, and other employee benefit and compensation plans maintained by The Timken Company. Following the spinoff (or earlier, in the case of the tax-qualified defined benefit plans and retiree medical plans), pursuant to the employee matters agreement, TimkenSteel employees and former employees generally participate in similar plans and arrangements established and maintained by TimkenSteel. The employee matters agreement provides for the bifurcation of equity awards as described in Note 11 - Stock-Based Compensation. Among other things, the employee matters agreement also provides for TimkenSteel’s assumption of certain employment-related contracts that its employees originally entered into with The Timken Company, the allocation of certain employee liabilities and the cooperation between TimkenSteel and The Timken Company in the sharing of employee information.

Relationships with The Timken Company and Related Entities

Prior to the spinoff on June 30, 2014, TimkenSteel was managed and operated in the normal course of business with other affiliates of The Timken Company. Transactions between The Timken Company and TimkenSteel, with the exception of sale and purchase transactions and reimbursements for payments made to third-party service providers by The Timken Company on TimkenSteel’s behalf, are reflected in equity in the Consolidated Balance Sheets as net parent investment and in the Consolidated Statements of Cash Flows as a financing activity in net transfers (to)/from The Timken Company and affiliates.

Transactions with Other Timken Businesses

TimkenSteel sold finished goods to The Timken Company. During the years ended December 31, 2018, 2017 and 2016, revenues from related-party sales of products totaled $43.2 million or 2.7% of net sales, $48.5 million, or 3.6% of net sales, and $32.7 million or 3.8% of net sales, respectively.

TimkenSteel did not purchase material from The Timken Company during the years ending December 31, 2018, 2017 and 2016. In addition, certain of TimkenSteel’s third-party service providers were paid by The Timken Company on behalf of TimkenSteel. TimkenSteel would subsequently reimburse The Timken Company in cash for such payments.

Material Agreements Between TimkenSteel and The Timken Company

On June 30, 2014, TimkenSteel entered into a separation and distribution agreement and several other agreements with The Timken Company to affect the spinoff and to provide a framework for the relationship with The Timken Company. These agreements govern the relationship between TimkenSteel and The Timken Company subsequent to the completion of the spinoff and provide for the allocation between TimkenSteel and The Timken Company of assets, liabilities and obligations attributable to periods prior to the spinoff. Because these agreements were entered into in the context of a related party transaction, the terms may not be comparable to terms that would be obtained in a transaction between unaffiliated parties.

Separation and Distribution Agreement — The separation and distribution agreement contains the key provisions relating to the spinoff, including provisions relating to the principal intercompany transactions required to effect the spinoff, the conditions to the spinoff and provisions governing the relationships between TimkenSteel and The Timken Company after the spinoff.

Tax Sharing Agreement — The tax sharing agreement generally governs TimkenSteel’s and The Timken Company’s respective rights, responsibilities and obligations after the spinoff with respect to taxes for any tax period ending on or before the distribution date, as well as tax periods beginning before and ending after the distribution date. Generally, TimkenSteel is liable for all pre-distribution U.S. federal income taxes, foreign income taxes and non-income taxes attributable to TimkenSteel’s business, and all other taxes attributable to TimkenSteel, paid after the distribution. In addition, the tax sharing agreement addresses the allocation of liability for taxes that are incurred as a result of restructuring activities undertaken to effectuate the distribution. The tax sharing agreement also provides that TimkenSteel is liable for taxes incurred by The Timken Company that arise as a result of TimkenSteel’s taking or failing to take, as the case may be, certain actions that result in the distribution failing to meet the requirements of a tax-free distribution under Section 355 of the Internal Revenue Code of 1986, as amended.

Employee Matters Agreement — TimkenSteel entered into an employee matters agreement with The Timken Company, which generally provides that TimkenSteel and The Timken Company each has responsibility for its own employees and compensation plans, subject to certain exceptions as described in the agreement. In general, prior to the spinoff, TimkenSteel employees participated in various retirement, health and welfare, and other employee benefit and compensation plans maintained by The Timken Company. Following the spinoff (or earlier, in the case of the tax-qualified defined benefit plans and retiree medical plans), pursuant to the employee matters agreement, TimkenSteel employees and former employees generally participate in similar plans and arrangements established and maintained by TimkenSteel. The employee matters agreement provides for the bifurcation of equity awards as described in Note 11 - Stock-Based Compensation. Among other things, the employee matters agreement also provides for TimkenSteel’s assumption of certain employment-related contracts that its employees originally entered into with The Timken Company, the allocation of certain employee liabilities and the cooperation between TimkenSteel and The Timken Company in the sharing of employee information.