Concentrations	12 Months Ended
Dec. 31, 2016
Risks And Uncertainties [Abstract]
Concentrations	11. Concentrations Financial instruments, which are potentially subject to counterparty performance and concentrations of credit risk, consist primarily of trade accounts receivable. The Company manages these risks by conducting credit evaluations of customers prior to delivery or commencement of services. When the Company enters into a sales contract, collateral is normally not required from the customer. Payments are typically due within 30 days of billing. An allowance for potential credit losses is maintained, and losses have historically been within management’s expectations. No customer represented greater than 10% of total sales for the years ended December 31, 2016, 2015 and 2014. The Company is also subject to counter party performance risk of loss in the event of non-performance by counterparties to financial instruments, such as cash and investments and derivative transactions. Cash and investments are held by well-established financial institutions and invested in AAA rated mutual funds or United States Government securities. The Company is exposed to swap counterparty credit risk with financial institutions. The Company’s counterparty is a well-established financial institution. Approximately 43% of the Company’s labor force (14% and 72% in the United States and Europe, respectively) is represented by collective bargaining agreements. The Company is a party to four U.S. collective bargaining agreements. The agreements will expire June 2017, July 2017, February 2018, and November 2019, respectively. The Company intends to renegotiate these contracts as they become due, though there is no assurance that this effort will be successful.

Concentrations

12 Months Ended

Dec. 31, 2016

11. Concentrations

Financial instruments, which are potentially subject to counterparty performance and concentrations of credit risk, consist primarily of trade accounts receivable. The Company manages these risks by conducting credit evaluations of customers prior to delivery or commencement of services. When the Company enters into a sales contract, collateral is normally not required from the customer. Payments are typically due within 30 days of billing. An allowance for potential credit losses is maintained, and losses have historically been within management’s expectations. No customer represented greater than 10% of total sales for the years ended December 31, 2016, 2015 and 2014.

The Company is also subject to counter party performance risk of loss in the event of non-performance by counterparties to financial instruments, such as cash and investments and derivative transactions. Cash and investments are held by well-established financial institutions and invested in AAA rated mutual funds or United States Government securities. The Company is exposed to swap counterparty credit risk with financial institutions. The Company’s counterparty is a well-established financial institution.

Approximately 43% of the Company’s labor force (14% and 72% in the United States and Europe, respectively) is represented by collective bargaining agreements. The Company is a party to four U.S. collective bargaining agreements. The agreements will expire June 2017, July 2017, February 2018, and November 2019, respectively. The Company intends to renegotiate these contracts as they become due, though there is no assurance that this effort will be successful.