Goodwill and Identifiable Intangible Assets, Net (Tables)

9 Months Ended

Sep. 30, 2019

Goodwill and Identifiable Intangible Assets, Net

Schedule of changes in the carrying amount of goodwill

The changes in the carrying amount of goodwill are as follows (in thousands):

	Mechanical Services		Electrical Services
	Segment		Segment		Total
Balance at December 31, 2017	$	200,584	$	—	$	200,584
Additions (See Note 4)		34,598		—		34,598
Impairment adjustment		—		—		—
Balance at December 31, 2018		235,182		—		235,182
Additions (See Note 4)		579		96,439		97,018
Impact of segment reorganization		(1,101)		1,101		—
Impairment adjustment		—		—		—
Balance at September 30, 2019	$	234,660	$	97,540	$	332,200

Schedule of components of identifiable intangible assets

Identifiable intangible assets consist of the following (dollars in thousands):

	Estimated	September 30, 2019				December 31, 2018
	Useful Lives	Gross Book		Accumulated		Gross Book		Accumulated
	in Years	Value		Amortization		Value		Amortization
Customer relationships	1 - 15	$	182,963	$	(75,455)	$	128,480	$	(60,731)
Backlog	1 - 2		13,700		(11,906)		9,100		(8,260)
Tradenames	2 - 25		71,995		(14,561)		39,395		(12,709)
Total		$	268,658	$	(101,922)	$	176,975	$	(81,700)

Schedule of future amortization expense of identifiable intangible assets

At September 30, 2019, future amortization expense of identifiable intangible assets is as follows (in thousands):

Year ended December 31—
2019 (remainder of the year)	$	6,844
2020		23,213
2021		19,158
2022		16,536
2023		15,082
Thereafter		85,903
Total	$	166,736