Intangible Assets

3 Months Ended

Mar. 31, 2020

Goodwill And Intangible Assets Disclosure [Abstract]

8.	Intangible Assets

The gross amount and accumulated amortization of intangible assets with finite useful lives included in “Intangible assets, net” on the consolidated balance sheets are as follows (in thousands except for years):

	March 31, 2020							December 31, 2019							Weighted Average
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Amortization Period (in years)
Backlog	$	109,255	$	(91,704	)	$	17,551	$	109,255	$	(87,510	)	$	21,745		3
Customer relationships		228,529		(78,533	)		149,996		228,529		(67,809	)		160,720		7
Leases		670		(585	)		85		670		(580	)		90		5
Developed technology		110,939		(47,799	)		63,140		110,939		(40,749	)		70,190		4
Trade name		8,200		(6,242	)		1,958		8,200		(5,667	)		2,533		1
Non-compete agreements		3,600		(1,200	)		2,400		3,600		(925	)		2,675		3
In process research and development		1,800					1,800		1,800		-			1,800	n/a
Other intangibles		275		(177	)		98		275		(170	)		105		10
Total intangible assets	$	463,268	$	(226,240	)	$	237,028	$	463,268	$	(203,410	)	$	259,858

The aggregate amortization expense of intangible assets for the three months ended March 31, 2020 and March 31, 2019 was $22.7 million and $21.0 million, respectively.

Estimated amortization expense for the remainder of the current fiscal year and in each of the next four years and beyond is as follows (in thousands):

	March 31, 2020
2020 (remaining)	$	64,042
2021		81,527
2022		35,864
2023		23,549
2024		9,098
Thereafter		21,147
Total	$	235,227