Segment Information

Our reportable segments reflect certain reclassifications of prior year amounts from our United States mechanical construction and facilities services segment to our United States building services segment due to changes in our internal reporting structure.

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 our 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 nine months ended September 30, 2017 and 2016 (in thousands):



	For the three months ended September 30,
	2017			2016
Revenues from unrelated entities:
United States electrical construction and facilities services	$	457,919		$	458,553
United States mechanical construction and facilities services	760,084			691,818
United States building services	437,107			460,715
United States industrial services	145,679			239,052
Total United States operations	1,800,789			1,850,138
United Kingdom building services	85,902			73,036
Total worldwide operations	$	1,886,691		$	1,923,174

Total revenues:
United States electrical construction and facilities services	$	460,066		$	465,476
United States mechanical construction and facilities services	767,398			696,549
United States building services	451,396			475,106
United States industrial services	147,133			239,489
Less intersegment revenues	(25,204		)	(26,482		)
Total United States operations	1,800,789			1,850,138
United Kingdom building services	85,902			73,036
Total worldwide operations	$	1,886,691		$	1,923,174



	For the nine months ended September 30,
	2017			2016
Revenues from unrelated entities:
United States electrical construction and facilities services	$	1,350,157		$	1,227,474
United States mechanical construction and facilities services	2,173,030			1,925,793
United States building services	1,315,401			1,366,973
United States industrial services	591,694			830,064
Total United States operations	5,430,282			5,350,304
United Kingdom building services	244,078			251,256
Total worldwide operations	$	5,674,360		$	5,601,560

Total revenues:
United States electrical construction and facilities services	$	1,355,206		$	1,249,681
United States mechanical construction and facilities services	2,197,231			1,937,089
United States building services	1,360,189			1,407,361
United States industrial services	593,648			831,111
Less intersegment revenues	(75,992		)	(74,938		)
Total United States operations	5,430,282			5,350,304
United Kingdom building services	244,078			251,256
Total worldwide operations	$	5,674,360		$	5,601,560



	For the three months ended September 30,
	2017			2016
Operating income (loss):
United States electrical construction and facilities services	$	46,583		$	30,927
United States mechanical construction and facilities services	57,484			38,890
United States building services	25,981			23,125
United States industrial services	(4,844		)	14,586
Total United States operations	125,204			107,528
United Kingdom building services	3,933			2,591
Corporate administration	(22,632		)	(23,516		)
Restructuring expenses	(46		)	(539		)
Total worldwide operations	106,459			86,064
Other corporate items:
Interest expense	(3,324		)	(3,479		)
Interest income	277			161
Income from continuing operations before income taxes	$	103,412		$	82,746



	For the nine months ended September 30,
	2017			2016
Operating income (loss):
United States electrical construction and facilities services	$	109,735		$	70,645
United States mechanical construction and facilities services	150,971			100,607
United States building services	60,375			55,658
United States industrial services	16,573			66,600
Total United States operations	337,654			293,510
United Kingdom building services	9,109			9,160
Corporate administration	(63,755		)	(67,431		)
Restructuring expenses	(954		)	(1,271		)
Total worldwide operations	282,054			233,968
Other corporate items:
Interest expense	(9,464		)	(8,973		)
Interest income	607			518
Income from continuing operations before income taxes	$	273,197		$	225,513



	September 30, 2017		December 31, 2016
Total assets:
United States electrical construction and facilities services	$	595,680	$	631,581
United States mechanical construction and facilities services	1,055,857		954,633
United States building services	774,449		753,434
United States industrial services	840,757		850,434
Total United States operations	3,266,743		3,190,082
United Kingdom building services	121,659		105,081
Corporate administration	577,919		557,275
Total worldwide operations	$	3,966,321	$	3,852,438