Intangible Assets

3 Months Ended

Mar. 31, 2016

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible Assets

The Company's intangible assets with finite lives include customer relationships and trade names and are predominantly within the Utility T&D segment. The changes in the carrying amounts of intangible assets for the three months ended March 31, 2016 are detailed below (in thousands):

	Customer Relationships			Trademark / Tradename			Total
Balance as of December 31, 2015	$	82,044		$	4,818		$	86,862
Amortization	(2,171		)	(267		)	(2,438		)
Balance as of March 31, 2016	$	79,873		$	4,551		$	84,424
Weighted average remaining amortization period	9.2 years			4.3 years

Intangible assets are amortized on a straight-line basis over their estimated useful lives, which range from 5 to 15 years.

Estimated amortization expense for the remainder of 2016 and each of the subsequent five years and thereafter is as follows (in thousands):

Fiscal year:
Remainder of 2016	$	7,316
2017	9,754
2018	9,754
2019	9,754
2020	9,135
2021	8,597
Thereafter	30,114
Total amortization	$	84,424