Segment Information

We have the following reportable segments, which provide services associated with the design, integration, installation, start-up, operation and maintenance of various systems: (a) United States electrical construction and facilities services (involving systems for electrical power transmission and distribution; premises electrical and lighting systems; process instrumentation in the refining, chemical process, food process and mining industries; low-voltage systems, such as fire alarm, security and process control; voice and data communication; roadway and transit lighting; and fiber optic lines); (b) United States mechanical construction and facilities services (involving systems for heating, ventilation, air conditioning, refrigeration and clean-room process ventilation; fire protection; plumbing, process and high-purity piping; controls and filtration; water and wastewater treatment; central plant heating and cooling; cranes and rigging; millwrighting; and steel fabrication, erection and welding); (c) United States building services; (d) United States industrial services; and (e) United Kingdom building services. The “United States building services” and “United Kingdom building services” segments principally consist of those operations which provide a portfolio of services needed to support the operation and maintenance of customers’ facilities, including commercial and government site-based operations and maintenance; facility maintenance and services, including reception, security and catering services; outage services to utilities and industrial plants; military base operations support services; mobile maintenance and services; floor care and janitorial services; landscaping, lot sweeping and snow removal; facilities management; vendor management; call center services; installation and support for building systems; program development, management and maintenance for energy systems; technical consulting and diagnostic services; infrastructure and building projects for federal, state and local governmental agencies and bodies; and small modification and retrofit projects, which services are not generally related to customers’ construction programs. The “United States industrial services” segment principally consists of those operations which provide industrial maintenance and services, including those for refineries and petrochemical plants, including on-site repairs, maintenance and service of heat exchangers, towers, vessels and piping; design, manufacturing, repair and hydro blast cleaning of shell and tube heat exchangers and related equipment; refinery turnaround planning and engineering services; specialty welding services; overhaul and maintenance of critical process units in refineries and petrochemical plants; and specialty technical services for refineries and petrochemical plants.

The following tables present information about industry segments and geographic areas for the three months ended March 31, 2018 and 2017 (in thousands):



	For the three months ended March 31,
	2018			2017
Revenues from unrelated entities:
United States electrical construction and facilities services	$	454,752		$	443,016
United States mechanical construction and facilities services	698,847			671,129
United States building services	454,752			440,030
United States industrial services	185,147			258,539
Total United States operations	1,793,498			1,812,714
United Kingdom building services	106,890			79,018
Total worldwide operations	$	1,900,388		$	1,891,732

Total revenues:
United States electrical construction and facilities services	$	457,169		$	444,016
United States mechanical construction and facilities services	705,880			679,391
United States building services	470,099			454,944
United States industrial services	185,720			258,905
Less intersegment revenues	(25,370		)	(24,542		)
Total United States operations	1,793,498			1,812,714
United Kingdom building services	106,890			79,018
Total worldwide operations	$	1,900,388		$	1,891,732



	For the three months ended March 31,
	2018			2017
Operating income (loss):
United States electrical construction and facilities services	$	35,851		$	31,034
United States mechanical construction and facilities services	39,572			40,433
United States building services	17,034			14,209
United States industrial services	3,469			17,044
Total United States operations	95,926			102,720
United Kingdom building services	4,570			1,679
Corporate administration	(21,665		)	(21,060		)
Restructuring expenses	(90		)	(565		)
Total worldwide operations	78,741			82,774
Other corporate items:
Interest expense	(2,996		)	(3,071		)
Interest income	544			257
Income from continuing operations before income taxes	$	76,289		$	79,960



	March 31, 2018		December 31, 2017
Total assets:
United States electrical construction and facilities services	$	605,483	$	617,471
United States mechanical construction and facilities services	1,058,495		1,097,240
United States building services	783,271		764,085
United States industrial services	776,659		772,899
Total United States operations	3,223,908		3,251,695
United Kingdom building services	157,380		131,806
Corporate administration	460,711		582,403
Total worldwide operations	$	3,841,999	$	3,965,904