Goodwill and Identifiable Intangible Assets, Net (Tables)

6 Months Ended

Jun. 30, 2020

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, 2018	$	235,182	$	—	$	235,182
Acquisitions and purchase price adjustments (See Note 4)		579		96,686		97,265
Impact of segment reorganization		(1,101)		1,101		—
Balance at December 31, 2019		234,660		97,787		332,447
Acquisitions and purchase price adjustments (See Note 4)		73,409		14,926		88,335
Balance at June 30, 2020	$	308,069	$	112,713	$	420,782

Schedule of components of identifiable intangible assets

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

	Estimated	June 30, 2020				December 31, 2019
	Useful Lives	Gross Book		Accumulated		Gross Book		Accumulated
	in Years	Value		Amortization		Value		Amortization
Customer relationships	1 - 15	$	231,492	$	(91,882)	$	183,061	$	(80,813)
Backlog	1 - 2		12,600		(10,822)		7,400		(6,388)
Tradenames	2 - 25		85,695		(16,919)		71,995		(15,281)
Total		$	329,787	$	(119,623)	$	262,456	$	(102,482)

Schedule of future amortization expense of identifiable intangible assets

At June 30, 2020, future amortization expense of identifiable intangible assets is as follows (in thousands):

Year ended December 31—
2020 (remainder of the year)	$	15,557
2021		24,610
2022		21,989
2023		20,535
2024		19,185
Thereafter		108,288
Total	$	210,164