Credit Facilities	12 Months Ended
Dec. 31, 2015
Debt Disclosure [Abstract]
Credit Facilities	CREDIT FACILITIES Short-Term Line of Credit Our short-term line of credit represents borrowings by one of our subsidiaries. The short-term line of credit balance was $2.0 million and $3.2 million at December 31, 2015 and 2014, respectively. This facility is renewable annually and the interest rate associated with this line of credit was 5.1% and 6.3% per annum at December 31, 2015 and 2014, respectively. Credit Agreement The new credit agreement ("Credit Agreement") that we entered into on May 11, 2015 closed in connection with the spin-off transaction. The Credit Agreement provides for a senior secured revolving credit facility in an aggregate amount of up to $600 million, which is scheduled to mature on June 30, 2020. The proceeds of loans under the Credit Agreement are available for working capital needs and other general corporate purposes, and the full amount is available for the issuance of letters of credit. The Credit Agreement contains an accordion feature that allows us, subject to the satisfaction of certain conditions, including the receipt of increased commitments from existing lenders or new commitments from new lenders, to increase the amount of the commitments under the revolving credit facility in an aggregate amount not to exceed the sum of (i) $200 million plus (ii) an unlimited amount, so long as for any commitment increase under this subclause (ii) our senior secured leverage ratio (assuming the full amount of any commitment increase under this subclause (ii) is drawn) is equal to or less than 2.0 to 1.0 after giving pro forma effect thereto. The Credit Agreement and our obligations under certain hedging agreements and cash management agreements with our lenders and their affiliates are (i) guaranteed by substantially all of our wholly owned domestic subsidiaries, but excluding our captive insurance subsidiary, and (ii) secured by first-priority liens on certain assets owned by us and the guarantors. The Credit Agreement requires interest payments on revolving loans on a periodic basis until maturity. We may prepay all loans at any time without premium or penalty (other than customary LIBOR breakage costs), subject to notice requirements. The Credit Agreement requires us to make certain prepayments on any outstanding revolving loans after receipt of cash proceeds from certain asset sales or other events, subject to certain exceptions and a right to reinvest such proceeds in certain circumstances, but such prepayments will not require us to reduce the commitments under the Credit Agreement. Loans outstanding under the Credit Agreement bear interest at our option at either the LIBOR rate plus a margin ranging from 1.375% to 1.875% per year or the base rate (the highest of the Federal Funds rate plus 0.5%, the one month LIBOR rate plus 1.0% and the administrative agent's prime rate) plus a margin ranging from 0.375% to 0.875% per year. A commitment fee is charged on the unused portion of the revolving credit facility, and that fee varies between 0.25% and 0.35% per year. Additionally, a letter of credit fee of between 1.375% and 1.875% per year is charged with respect to the amount of each financial letter of credit issued, and a letter of credit fee of between 0.825% and 1.125% per year is charged with respect to the amount of each performance letter of credit issued. The applicable rates for loans, the commitment fee and the letter of credit fees set forth above vary quarterly based on our leverage ratio. The applicable margin for loans, the commitment fee and the letter of credit fees set forth above vary quarterly based on our leverage ratio. Based on our leverage ratio at December 31, 2015, the applicable margin for LIBOR and base rate loans was 1.375% and 0.375%, respectively. The commitment fee for the unused portions of the revolving credit facility was 0.25% and the letter of credit fees for financial and performance letters of credit was 1.375% and 0.825%, respectively. The Credit Agreement includes financial covenants that are tested on a quarterly basis, based on the rolling four-quarter period that ends on the last day of each fiscal quarter. The maximum permitted leverage ratio is 3.00 to 1.00, which ratio may be increased to 3.25 to 1.00 for up to four consecutive fiscal quarters after a material acquisition. The minimum consolidated interest coverage ratio is 4.00 to 1.00. In addition, the Credit Agreement contains various restrictive covenants, including with respect to debt, liens, investments, mergers, acquisitions, dividends, equity repurchases and asset sales. At December 31, 2015, we had no borrowings outstanding under the revolving credit facility, and after giving effect to the leverage ratio and $109.6 million of letters of credit issued under the Credit Agreement, we had approximately $373 million available for borrowings or to meet letter of credit requirements. The Credit Agreement generally includes customary events of default for a secured credit facility. If an event of default relating to bankruptcy or other insolvency events with respect to us occurs under the Credit Agreement, all obligations will immediately become due and payable. If any other event of default exists, the lenders will be permitted to accelerate the maturity of the obligations outstanding. If any event of default occurs, the lenders are permitted to terminate their commitments thereunder and exercise other rights and remedies, including the commencement of foreclosure or other actions against the collateral. Additionally, if we are unable to make any of the representations and warranties in the Credit Agreement, we will be unable to borrow funds or have letters of credit issued. At December 31, 2015, we were in compliance with all of the covenants set forth in the Credit Agreement. Other Credit Arrangements Certain subsidiaries have credit arrangements with various commercial banks and other financial institutions for the issuance of letters of credit and bank guarantees in association with contracting activity. The aggregate value of all such letters of credit and bank guarantees as of December 31, 2015 was $193.1 million. We have posted surety bonds to support contractual obligations to customers relating to certain projects. We utilize bonding facilities to support such obligations, but the issuance of bonds under those facilities is typically at the surety's discretion. Although there can be no assurance that we will maintain our surety bonding capacity, we believe our current capacity is more than adequate to support our existing project requirements for the next twelve months. In addition, these bonds generally indemnify customers should we fail to perform our obligations under the applicable contracts. We, and certain of our subsidiaries, have jointly executed general agreements of indemnity in favor of surety underwriters relating to surety bonds those underwriters issue in support of some of our contracting activity. As of December 31, 2015, bonds issued and outstanding under these arrangements in support of contracts totaled approximately $541.7 million.

CREDIT FACILITIES

Short-Term Line of Credit

Our short-term line of credit represents borrowings by one of our subsidiaries. The short-term line of credit balance was $2.0 million and $3.2 million at December 31, 2015 and 2014, respectively. This facility is renewable annually and the interest rate associated with this line of credit was 5.1% and 6.3% per annum at December 31, 2015 and 2014, respectively.

Credit Agreement

The new credit agreement ("Credit Agreement") that we entered into on May 11, 2015 closed in connection with the spin-off transaction. The Credit Agreement provides for a senior secured revolving credit facility in an aggregate amount of up to $600 million, which is scheduled to mature on June 30, 2020. The proceeds of loans under the Credit Agreement are available for working capital needs and other general corporate purposes, and the full amount is available for the issuance of letters of credit.

The Credit Agreement contains an accordion feature that allows us, subject to the satisfaction of certain conditions, including the receipt of increased commitments from existing lenders or new commitments from new lenders, to increase the amount of the commitments under the revolving credit facility in an aggregate amount not to exceed the sum of (i) $200 million plus (ii) an unlimited amount, so long as for any commitment increase under this subclause (ii) our senior secured leverage ratio (assuming the full amount of any commitment increase under this subclause (ii) is drawn) is equal to or less than 2.0 to 1.0 after giving pro forma effect thereto.

The Credit Agreement and our obligations under certain hedging agreements and cash management agreements with our lenders and their affiliates are (i) guaranteed by substantially all of our wholly owned domestic subsidiaries, but excluding our captive insurance subsidiary, and (ii) secured by first-priority liens on certain assets owned by us and the guarantors. The Credit Agreement requires interest payments on revolving loans on a periodic basis until maturity. We may prepay all loans at any time without premium or penalty (other than customary LIBOR breakage costs), subject to notice requirements. The Credit Agreement requires us to make certain prepayments on any outstanding revolving loans after receipt of cash proceeds from certain asset sales or other events, subject to certain exceptions and a right to reinvest such proceeds in certain circumstances, but such prepayments will not require us to reduce the commitments under the Credit Agreement.

Loans outstanding under the Credit Agreement bear interest at our option at either the LIBOR rate plus a margin ranging from 1.375% to 1.875% per year or the base rate (the highest of the Federal Funds rate plus 0.5%, the one month LIBOR rate plus 1.0% and the administrative agent's prime rate) plus a margin ranging from 0.375% to 0.875% per year. A commitment fee is charged on the unused portion of the revolving credit facility, and that fee varies between 0.25% and 0.35% per year. Additionally, a letter of credit fee of between 1.375% and 1.875% per year is charged with respect to the amount of each financial letter of credit issued, and a letter of credit fee of between 0.825% and 1.125% per year is charged with respect to the amount of each performance letter of credit issued. The applicable rates for loans, the commitment fee and the letter of credit fees set forth above vary quarterly based on our leverage ratio. The applicable margin for loans, the commitment fee and the letter of credit fees set forth above vary quarterly based on our leverage ratio. Based on our leverage ratio at December 31, 2015, the applicable margin for LIBOR and base rate loans was 1.375% and 0.375%, respectively. The commitment fee for the unused portions of the revolving credit facility was 0.25% and the letter of credit fees for financial and performance letters of credit was 1.375% and 0.825%, respectively.

The Credit Agreement includes financial covenants that are tested on a quarterly basis, based on the rolling four-quarter period that ends on the last day of each fiscal quarter. The maximum permitted leverage ratio is 3.00 to 1.00, which ratio may be increased to 3.25 to 1.00 for up to four consecutive fiscal quarters after a material acquisition. The minimum consolidated interest coverage ratio is 4.00 to 1.00. In addition, the Credit Agreement contains various restrictive covenants, including with respect to debt, liens, investments, mergers, acquisitions, dividends, equity repurchases and asset sales. At December 31, 2015, we had no borrowings outstanding under the revolving credit facility, and after giving effect to the leverage ratio and $109.6 million of letters of credit issued under the Credit Agreement, we had approximately $373 million available for borrowings or to meet letter of credit requirements.

The Credit Agreement generally includes customary events of default for a secured credit facility. If an event of default relating to bankruptcy or other insolvency events with respect to us occurs under the Credit Agreement, all obligations will immediately become due and payable. If any other event of default exists, the lenders will be permitted to accelerate the maturity of the obligations outstanding. If any event of default occurs, the lenders are permitted to terminate their commitments thereunder and exercise other rights and remedies, including the commencement of foreclosure or other actions against the collateral. Additionally, if we are unable to make any of the representations and warranties in the Credit Agreement, we will be unable to borrow funds or have letters of credit issued. At December 31, 2015, we were in compliance with all of the covenants set forth in the Credit Agreement.

Other Credit Arrangements

Certain subsidiaries have credit arrangements with various commercial banks and other financial institutions for the issuance of letters of credit and bank guarantees in association with contracting activity. The aggregate value of all such letters of credit and bank guarantees as of December 31, 2015 was $193.1 million.

We have posted surety bonds to support contractual obligations to customers relating to certain projects. We utilize bonding facilities to support such obligations, but the issuance of bonds under those facilities is typically at the surety's discretion. Although there can be no assurance that we will maintain our surety bonding capacity, we believe our current capacity is more than adequate to support our existing project requirements for the next twelve months. In addition, these bonds generally indemnify customers should we fail to perform our obligations under the applicable contracts. We, and certain of our subsidiaries, have jointly executed general agreements of indemnity in favor of surety underwriters relating to surety bonds those underwriters issue in support of some of our contracting activity. As of December 31, 2015, bonds issued and outstanding under these arrangements in support of contracts totaled approximately $541.7 million.