Notes Payable and Long-Term Debt (Details 4)				3 Months Ended						3 Months Ended
	Mar. 31, 2015 Other Foreign Banks USD ($)	Mar. 31, 2015 Line of credit National Bank of Abu Dhabi USD ($)	Mar. 31, 2015 Line of credit National Bank of Abu Dhabi AED	Mar. 31, 2015 Line of credit National Bank of Abu Dhabi Emirates InterBank Offer Rate	Mar. 31, 2015 Line of credit National Bank of Abu Dhabi Emirates InterBank Offer Rate Minimum	Mar. 31, 2015 Letters of credit National Bank of Abu Dhabi USD ($)	Mar. 31, 2015 Letters of credit National Bank of Abu Dhabi AED	Mar. 31, 2015 Hill Spain Line of credit Ibercaja Bank In Spain USD ($)	Mar. 31, 2015 Hill Spain Line of credit Ibercaja Bank In Spain EUR (€)	Mar. 31, 2015 Engineering S.A. Revolving credit facility USD ($) item loanfacility	Mar. 31, 2015 Engineering S.A. Revolving credit facility BRL item loanfacility	Mar. 31, 2015 Engineering S.A. Line of credit Brazil Bank Revolving Credit Facility 1 USD ($)
Description of terms of credit agreement
Maximum borrowing capacity	$ 71,739,000	$ 3,131,000	11,500,000			$ 34,589,000	127,033,000	$ 569,000	€ 525,000	$ 681,000	2,200,000
Decrease in amount on quarterly basis									175,000
Letters of credit outstanding	28,243,000
Reference rate				one-month Emirates InterBank Offer Rate
Basis of effective interest rate (as a percent)				3.00%
Interest rate (as a percent)					5.50%			6.75%	6.75%
Effective interest rate (as a percent)				4.37%
Amounts outstanding		$ 1,575,000	5,786,000			$ 34,589,000	127,033,000	$ 556,000	€ 513,000			$ 0
Number of revolving credit lines maintained by Engineering S.A.										3	3
Number of banks involved in revolving credit facility										2	2
Weighted average interest rate (as a percent)										3.25%	3.25%
Period of automatic renewal										3 months	3 months