CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) $ in Thousands	Jun. 30, 2015 USD ($) shares	Jun. 30, 2015 € / shares	Dec. 31, 2014 USD ($) shares	Dec. 31, 2014 € / shares
Cash and cash equivalents related to variable interest entities (VIEs)	$ 355,088		$ 351,323
Accounts receivable, net related to VIE	1,326,858		1,306,567
Costs and estimated earnings in excess of billings ($38,110 and $29,677 related to VIEs)	1,605,190		774,644
Other current assets ($247,027 and $104,447 related to VIEs)	378,532		238,783
Property and equipment, net ($20,439 and $21,868 related to VIEs)	741,469		771,651
Accounts payable related to VIEs	1,179,056		1,256,854
Billings in excess of costs and estimated earnings ($647,741 and $282,351 related to VIEs)	$ 2,189,584		$ 1,985,488
Common stock, par value (Euro per share) | € / shares		€ 0.01		€ 0.01
Common stock, shares authorized | shares	250,000,000		250,000,000
Common stock, shares issued | shares	108,757,000		108,407,000
Common stock, shares outstanding | shares	108,738,000		107,806,000
Treasury stock, shares | shares	19,000		601,000
Variable Interest Entity, Primary Beneficiary
Cash and cash equivalents related to variable interest entities (VIEs)	$ 192,219		$ 191,464
Accounts receivable, net related to VIE	298,294		235,018
Costs and estimated earnings in excess of billings ($38,110 and $29,677 related to VIEs)	38,110		29,677
Other current assets ($247,027 and $104,447 related to VIEs)	247,027		104,447
Property and equipment, net ($20,439 and $21,868 related to VIEs)	20,439		21,868
Accounts payable related to VIEs	217,676		279,597
Billings in excess of costs and estimated earnings ($647,741 and $282,351 related to VIEs)	$ 647,741		$ 282,351