Commitments and Contingencies Performance Bonds In certain circumstances, the Company is required to provide performance bonds to secure its contractual commitments. Management is not aware of any performance bonds issued for the Company that have ever been called by a customer. As of March 31, 2016 , outstanding performance bonds issued on behalf of the Companys electrical construction subsidiaries amounted to approximately $40.9 million . Collective Bargaining Agreements C&amp;C, one of the Companys electrical construction subsidiaries, is party to collective bargaining agreements with unions representing workers performing field construction operations. The collective bargaining agreements expire at various times and have typically been renegotiated and renewed on terms similar to the ones contained in the expiring agreements. The agreements require the subsidiary to pay specified wages, provide certain benefits to their respective union employees and contribute certain amounts to multi-employer pension plans and employee benefit trusts. The subsidiarys multi-employer pension plan contribution rates generally are specified in the collective bargaining agreements (usually on an annual basis), and contributions are made to the plans on a pay-as-you-go basis based on such subsidiarys union employee payrolls, which cannot be determined for future periods because contributions depend on, among other things, the number of union employees that such subsidiary employs at any given time; the plans in which it may participate vary depending on the projects it has ongoing at any time; and the need for union resources in connection with those projects. If the subsidiary withdraws from, or otherwise terminates its participation in, one or more multi-employer pension plans, or if the plans were to otherwise become substantially underfunded, such subsidiary could be assessed liabilities for additional contributions related to the underfunding of these plans. The Company is not aware of any amounts of withdrawal liabili