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 and six months ended June 30, 2018 and 2017 (in thousands):



	For the three months ended June 30,
	2018			2017
Revenues from unrelated entities:
United States electrical construction and facilities services	$	479,542		$	449,222
United States mechanical construction and facilities services	740,657			741,817
United States building services	461,033			438,264
United States industrial services	167,147			187,476
Total United States operations	1,848,379			1,816,779
United Kingdom building services	105,507			79,158
Total worldwide operations	$	1,953,886		$	1,895,937

Total revenues:
United States electrical construction and facilities services	$	481,379		$	451,124
United States mechanical construction and facilities services	750,326			750,442
United States building services	476,775			453,849
United States industrial services	167,868			187,610
Less intersegment revenues	(27,969		)	(26,246		)
Total United States operations	1,848,379			1,816,779
United Kingdom building services	105,507			79,158
Total worldwide operations	$	1,953,886		$	1,895,937



	For the six months ended June 30,
	2018			2017
Revenues from unrelated entities:
United States electrical construction and facilities services	$	934,294		$	892,238
United States mechanical construction and facilities services	1,439,504			1,412,946
United States building services	915,785			878,294
United States industrial services	352,294			446,015
Total United States operations	3,641,877			3,629,493
United Kingdom building services	212,397			158,176
Total worldwide operations	$	3,854,274		$	3,787,669

Total revenues:
United States electrical construction and facilities services	$	938,548		$	895,140
United States mechanical construction and facilities services	1,456,206			1,429,833
United States building services	946,874			908,793
United States industrial services	353,588			446,515
Less intersegment revenues	(53,339		)	(50,788		)
Total United States operations	3,641,877			3,629,493
United Kingdom building services	212,397			158,176
Total worldwide operations	$	3,854,274		$	3,787,669



	For the three months ended June 30,
	2018			2017
Operating income (loss):
United States electrical construction and facilities services	$	35,985		$	32,118
United States mechanical construction and facilities services	57,583			53,073
United States building services	22,430			20,237
United States industrial services	1,068			4,373
Total United States operations	117,066			109,801
United Kingdom building services	4,601			3,018
Corporate administration	(20,730		)	(20,063		)
Restructuring expenses	(374		)	(343		)
Impairment loss on identifiable intangible assets	(907		)	—
Total worldwide operations	99,656			92,413
Other corporate items:
Net periodic pension (cost) income	717			408
Interest expense	(3,457		)	(3,069		)
Interest income	634			73
Income from continuing operations before income taxes	$	97,550		$	89,825



	For the six months ended June 30,
	2018			2017
Operating income (loss):
United States electrical construction and facilities services	$	71,836		$	63,152
United States mechanical construction and facilities services	97,175			93,525
United States building services	39,507			34,502
United States industrial services	4,537			21,417
Total United States operations	213,055			212,596
United Kingdom building services	8,371			4,236
Corporate administration	(42,395		)	(41,123		)
Restructuring expenses	(464		)	(908		)
Impairment loss on identifiable intangible assets	(907		)	—
Total worldwide operations	177,660			174,801
Other corporate items:
Net periodic pension (cost) income	1,454			794
Interest expense	(6,453		)	(6,140		)
Interest income	1,178			330
Income from continuing operations before income taxes	$	173,839		$	169,785



	June 30, 2018		December 31, 2017
Total assets:
United States electrical construction and facilities services	$	622,290	$	617,471
United States mechanical construction and facilities services	1,093,404		1,097,240
United States building services	804,025		764,085
United States industrial services	778,030		772,899
Total United States operations	3,297,749		3,251,695
United Kingdom building services	144,959		131,806
Corporate administration	426,693		582,403
Total worldwide operations	$	3,869,401	$	3,965,904