Long-Term Debt	9 Months Ended
Sep. 30, 2018
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Revolving Credit Facility On June 28, 2018, we entered into a Second Amended and Restated Credit Agreement (the “Amended Credit Agreement”) among EnPro Industries, Inc. and EnPro Holdings, Inc., a wholly owned subsidiary of the Company (“EnPro Holdings”), as borrowers, the guarantors party thereto, the lenders party thereto and Bank of America, N.A., as Administrative Agent, Swing Line Lender and Letter of Credit Issuer. The Amended Credit Agreement provides for a five-year, senior secured revolving credit facility of $350.0 million (the “Revolving Credit Facility”). The Amended Credit Agreement also provides that the borrowers may seek incremental term loans and/or additional revolving credit commitments in an amount equal to the greater of $225.0 million and 100% of consolidated EBITDA (as defined) for the most recently ended four-quarter period for which we have reported financial results, plus additional amounts based on a consolidated senior secured leverage ratio. Borrowing availability under the Revolving Credit Facility is not limited by reference to a borrowing base. Initially, borrowings under the Revolving Credit Facility bear interest at an annual rate of LIBOR plus 1.75% or base rate plus 0.75%, although the interest rates under the Revolving Credit Facility are subject to incremental increases based on a consolidated total net leverage ratio. In addition, a commitment fee accrues with respect to the unused amount of the Revolving Credit Facility. The Company and EnPro Holdings are the permitted borrowers under the Revolving Credit Facility. The Company has the ability to add foreign subsidiaries as borrowers under the Revolving Credit Facility for up to $100.0 million (or its foreign currency equivalent) in aggregate borrowings, subject to certain conditions. Each of the Company’s domestic, consolidated subsidiaries are required to guarantee the obligations of the borrowers under the Revolving Credit Facility, and each of the Company’s existing domestic, consolidated subsidiaries has entered into the Amended Credit Agreement to provide such a guarantee. Borrowings under the Revolving Credit Facility are secured by a first priority pledge of certain assets. The Amended Credit Agreement contains certain financial covenants and required financial ratios including a maximum consolidated total net leverage and a minimum consolidated interest coverage as defined in the Amended Credit Agreement. We were in compliance with all covenants of the Revolving Credit Facility as of September 30, 2018. The borrowing availability under our Revolving Credit Facility at September 30, 2018 was $299.9 million after giving consideration to $16.0 million of outstanding letters of credit and $34.1 million of outstanding revolver borrowings. Senior Notes In September 2014, we completed an offering of $300 million aggregate principal amount of our 5.875% Senior Notes due 2022 (the “Senior Notes”). We issued the notes net of an original issue discount of $2.4 million. The Senior Notes were unsecured, unsubordinated obligations of EnPro and were scheduled to mature on September 15, 2022. Interest on the Senior Notes accrued at a rate of 5.875% per annum and was payable semi-annually in cash in arrears on March 15 and September 15 of each year. The debt discount was being amortized through interest expense until the scheduled maturity date resulting in an effective interest rate of 6.00%. In March 2017, we completed an add-on offering of $150 million of our 5.875% Senior Notes due 2022 (the “Additional Notes"). We issued the notes inclusive of an original issue premium of $1.5 million. The indenture for the Additional Notes contained the same provisions as the Senior Notes. The debt premium was being amortized through interest expense until the scheduled maturity date resulting in an effective interest rate of 5.66%. We redeemed the Senior Notes and the Additional Notes on October 31, 2018. See further discussion of this in Note 19, "Subsequent Events".

Long-Term Debt

Revolving Credit Facility

On June 28, 2018, we entered into a Second Amended and Restated Credit Agreement (the “Amended Credit Agreement”) among EnPro Industries, Inc. and EnPro Holdings, Inc., a wholly owned subsidiary of the Company (“EnPro Holdings”), as borrowers, the guarantors party thereto, the lenders party thereto and Bank of America, N.A., as Administrative Agent, Swing Line Lender and Letter of Credit Issuer. The Amended Credit Agreement provides for a five-year, senior secured revolving credit facility of $350.0 million (the “Revolving Credit Facility”). The Amended Credit Agreement also provides that the borrowers may seek incremental term loans and/or additional revolving credit commitments in an amount equal to the greater of $225.0 million and 100% of consolidated EBITDA (as defined) for the most recently ended four-quarter period for which we have reported financial results, plus additional amounts based on a consolidated senior secured leverage ratio.

Borrowing availability under the Revolving Credit Facility is not limited by reference to a borrowing base. Initially, borrowings under the Revolving Credit Facility bear interest at an annual rate of LIBOR plus 1.75% or base rate plus 0.75%, although the interest rates under the Revolving Credit Facility are subject to incremental increases based on a consolidated total net leverage ratio. In addition, a commitment fee accrues with respect to the unused amount of the Revolving Credit Facility.

The Company and EnPro Holdings are the permitted borrowers under the Revolving Credit Facility. The Company has the ability to add foreign subsidiaries as borrowers under the Revolving Credit Facility for up to $100.0 million (or its foreign currency equivalent) in aggregate borrowings, subject to certain conditions. Each of the Company’s domestic, consolidated subsidiaries are required to guarantee the obligations of the borrowers under the Revolving Credit Facility, and each of the Company’s existing domestic, consolidated subsidiaries has entered into the Amended Credit Agreement to provide such a guarantee.

Borrowings under the Revolving Credit Facility are secured by a first priority pledge of certain assets. The Amended Credit Agreement contains certain financial covenants and required financial ratios including a maximum consolidated total net leverage and a minimum consolidated interest coverage as defined in the Amended Credit Agreement. We were in compliance with all covenants of the Revolving Credit Facility as of September 30, 2018.

The borrowing availability under our Revolving Credit Facility at September 30, 2018 was $299.9 million after giving consideration to $16.0 million of outstanding letters of credit and $34.1 million of outstanding revolver borrowings.

Senior Notes

In September 2014, we completed an offering of $300 million aggregate principal amount of our 5.875% Senior Notes due 2022 (the “Senior Notes”). We issued the notes net of an original issue discount of $2.4 million.

The Senior Notes were unsecured, unsubordinated obligations of EnPro and were scheduled to mature on September 15, 2022. Interest on the Senior Notes accrued at a rate of 5.875% per annum and was payable semi-annually in cash in arrears on March 15 and September 15 of each year. The debt discount was being amortized through interest expense until the scheduled maturity date resulting in an effective interest rate of 6.00%.

In March 2017, we completed an add-on offering of $150 million of our 5.875% Senior Notes due 2022 (the “Additional Notes"). We issued the notes inclusive of an original issue premium of $1.5 million. The indenture for the Additional Notes contained the same provisions as the Senior Notes. The debt premium was being amortized through interest expense until the scheduled maturity date resulting in an effective interest rate of 5.66%.

We redeemed the Senior Notes and the Additional Notes on October 31, 2018. See further discussion of this in Note 19, "Subsequent Events".