Goodwill and Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

A summary of changes in Quanta’s goodwill is as follows (in thousands):



	Electric Power Infrastructure Services Division			Oil and Gas Infrastructure Services Division			Total
Balance at December 31, 2015:
Goodwill	$	1,226,245		$	366,306		1,592,551
Accumulated impairment	—			(39,893		)	(39,893		)
	1,226,245			326,413			1,552,658

Goodwill recorded related to 2016 acquisitions	24,168			21,018			45,186
Purchase price allocation adjustments	229			(214		)	15
Foreign currency translation adjustments	3,337			1,973			5,310

Balance at December 31, 2016:
Goodwill	1,253,979			388,923			1,642,902
Accumulated impairment	—			(39,733		)	(39,733		)
	1,253,979			349,190			1,603,169

Goodwill recorded related to 2017 acquisitions	5,866			296,542			302,408
Purchase price allocation adjustments	(619		)	(659		)	(1,278		)
Goodwill impairment during 2017	—			(57,011		)	(57,011		)
Foreign currency translation adjustments	13,301			8,011			21,312

Balance at December 31, 2017:
Goodwill	1,272,527			693,905			1,966,432
Accumulated impairment	—			(97,832		)	(97,832		)
	$	1,272,527		$	596,073		$	1,868,600

Other Intangible Assets

Quanta’s intangible assets subject to amortization and the remaining weighted average amortization periods related to such assets were as follows (in thousands except for weighted average amortization periods, which are in years):



	As of							As of							As of
	December 31, 2017							December 31, 2016							December 31, 2017
	Intangible Assets		Accumulated Amortization			Intangible Assets, Net		Intangible Assets		Accumulated Amortization			Intangible Assets, Net		Remaining Weighted Average Amortization Period in Years
Customer relationships	$	327,334	$	(137,333	)	$	190,001	$	244,329	$	(110,640	)	$	133,689	7.3
Backlog	136,266		(135,847		)	419		133,592		(132,441		)	1,151		1.1
Trade names	74,797		(17,057		)	57,740		54,723		(12,855		)	41,868		16.2
Non-compete agreements	37,760		(27,659		)	10,101		29,212		(25,546		)	3,666		3.9
Patented rights and developed technology	22,529		(17,611		)	4,918		22,480		(15,831		)	6,649		3.4
Total intangible assets subject to amortization	$	598,686	$	(335,507	)	$	263,179	$	484,336	$	(297,313	)	$	187,023	9.1

Estimated Future Aggregate Amortization Expense of Intangible Assets

The estimated future aggregate amortization expense of intangible assets subject to amortization as of December 31, 2017 is set forth below (in thousands):



For the Fiscal Year Ending December 31,
2018	$	39,188
2019	37,038
2020	35,639
2021	33,295
2022	29,764
Thereafter	88,255
Total	$	263,179