Goodwill and Related Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Changes in Carrying Amount of Goodwill

The changes in the carrying amount of goodwill for the years ended December 31 were as follows (in thousands):

	Renewable Energy & Conservation		Residential Products		Infrastructure Products		Total
Balance at December 31, 2018	$	71,827	$	198,075	$	31,678	$	301,580
Acquired goodwill	5,857		—		—		5,857
Adjustments to prior year acquisitions	(172)		—		—		(172)
Foreign currency translation	90		—		—		90
Balance at December 31, 2019	$	77,602	$	198,075	31,678		$	307,355
Acquired goodwill	197,866		7,377		—		205,243
Adjustments to prior year acquisitions	578		—		—		578
Foreign currency translation	1,103		—		—		1,103
Balance at December 31, 2020	$	277,149	$	205,452	31,678		$	514,279

Schedule of Acquired Intangible Assets

Acquired intangible assets consist of the following (in thousands):

	December 31, 2020				December 31, 2019
	Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization
Indefinite-lived intangible assets:
Trademarks	$	56,570	$	—	$	32,570	$	—
Finite-lived intangible assets:
Trademarks	5,818		3,385		4,340		2,680
Unpatented technology	38,752		17,765		28,177		15,196
Customer relationships	98,500		31,580		55,401		26,028
Non-compete agreements	4,885		1,747		1,649		1,499
Backlog	7,228		911		—		—
	155,183		55,388		89,567		45,403
Total acquired intangible assets	$	211,753	$	55,388	$	122,137	$	45,403

Schedule of Intangible Assets Amortization Expense

The following table summarizes amortization expense for the years ended December 31 (in thousands):

	2020		2019		2018
Amortization expense	$	9,663	$	6,891	$	7,190

Schedule of Amortization Expense

Amortization expense related to acquired intangible assets for the next five years ended December 31 is estimated as follows (in thousands):

	2021		2022		2023		2024		2025
Amortization expense	$	18,362	$	11,584	$	10,721	$	10,611	$	10,382