Equity	12 Months Ended
Dec. 31, 2017
Equity [Abstract]
Equity	Equity Common Stock The Company is authorized to issue up to 190,000,000 shares of common stock, par value $0.001 per share. As of December 31, 2017, an aggregate of 19,920,805 shares of its common stock were issued, and 17,914,599 shares were outstanding. Holders of shares of common stock are entitled to one vote for each share on each matter on which holders of common stock are entitled to vote. Holders of common stock are entitled to ratably receive dividends and other distributions when, as and if declared by the Company’s board of directors out of assets or funds legally available therefore. The ABL Facility, the Term Loan Facility and the Senior Notes each contain covenants that restrict the Company’s ability to pay dividends or make distributions on the common stock, subject to certain exceptions. In the event of the liquidation, dissolution or winding up of the Company, holders of common stock are entitled to share ratably in the Company assets, if any, remaining after the payment of all the Company’s debts and liabilities. Secondary Offering and Share Repurchase In March 2016, the Company’s Board of Directors approved a securities repurchase program (the “Program”) authorizing the Company to repurchase, in the aggregate, up to $125,000 of its outstanding common stock or warrants to purchase common stock. Under the Program, repurchases may be made on the open market or through private transactions, as determined by the Company’s management and in accordance with prevailing market conditions and federal securities laws and regulations. During the year ended December 31, 2017, the Company repurchased 513,801 shares at an average purchase price of $108.87 per share, excluding commissions, for a total cost of $55,935, of which $55,123 was settled in cash as of December 31, 2017. In March 2016, certain selling stockholders affiliated with Silver Point Capital, L.P., Oak Hill Advisors, L.P. and Capital World Investors (the “Selling Stockholders”) sold 2,278,031 shares, including overallotments, of the Company’s common stock at a public offering price of $68.00 per share, in a secondary public offering. Of the 2,278,031 shares sold in the offering, 350,000 shares were purchased by the Company for $23,800. The Company paid the underwriting discounts and commissions payable on the shares sold by the Selling Stockholders, excluding the shares the Company repurchased, resulting in $5,900 of fees incurred during 2016, which is included in other (expense) income, net in the consolidated statement of net income. The Company also incurred approximately $600 of other expenses related to legal and audit services which is included in selling, administration & engineering expenses in the consolidated statement of net income. The Company did not sell or receive any proceeds from the sales of shares by the Selling Stockholders. As of December 31, 2017, the Company had approximately $45,300 of repurchase authorization remaining under the Program.

Equity

Common Stock

The Company is authorized to issue up to 190,000,000 shares of common stock, par value $0.001 per share. As of December 31, 2017, an aggregate of 19,920,805 shares of its common stock were issued, and 17,914,599 shares were outstanding.

Holders of shares of common stock are entitled to one vote for each share on each matter on which holders of common stock are entitled to vote. Holders of common stock are entitled to ratably receive dividends and other distributions when, as and if declared by the Company’s board of directors out of assets or funds legally available therefore. The ABL Facility, the Term Loan Facility and the Senior Notes each contain covenants that restrict the Company’s ability to pay dividends or make distributions on the common stock, subject to certain exceptions.

In the event of the liquidation, dissolution or winding up of the Company, holders of common stock are entitled to share ratably in the Company assets, if any, remaining after the payment of all the Company’s debts and liabilities.

Secondary Offering and Share Repurchase

In March 2016, the Company’s Board of Directors approved a securities repurchase program (the “Program”) authorizing the Company to repurchase, in the aggregate, up to $125,000 of its outstanding common stock or warrants to purchase common stock. Under the Program, repurchases may be made on the open market or through private transactions, as determined by the Company’s management and in accordance with prevailing market conditions and federal securities laws and regulations. During the year ended December 31, 2017, the Company repurchased 513,801 shares at an average purchase price of $108.87 per share, excluding commissions, for a total cost of $55,935, of which $55,123 was settled in cash as of December 31, 2017.

In March 2016, certain selling stockholders affiliated with Silver Point Capital, L.P., Oak Hill Advisors, L.P. and Capital World Investors (the “Selling Stockholders”) sold 2,278,031 shares, including overallotments, of the Company’s common stock at a public offering price of $68.00 per share, in a secondary public offering. Of the 2,278,031 shares sold in the offering, 350,000 shares were purchased by the Company for $23,800. The Company paid the underwriting discounts and commissions payable on the shares sold by the Selling Stockholders, excluding the shares the Company repurchased, resulting in $5,900 of fees incurred during 2016, which is included in other (expense) income, net in the consolidated statement of net income. The Company also incurred approximately $600 of other expenses related to legal and audit services which is included in selling, administration & engineering expenses in the consolidated statement of net income. The Company did not sell or receive any proceeds from the sales of shares by the Selling Stockholders.

As of December 31, 2017, the Company had approximately $45,300 of repurchase authorization remaining under the Program.