Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of gross carrying amounts included within goodwill and intangible assets, related accumulated amortization and the weighted-average amortization periods of intangible assets

The gross carrying amounts of intangible assets included within other long-term assets, the related accumulated amortization, the net carrying amounts and the weighted-average amortization periods of the Company’s intangible assets are listed in the following tables (in thousands, except amortization period):

	December 31, 2019
							Weighted-
							Average
	Gross Carrying		Accumulated		Net Carrying		Amortization
	Amount		Amortization		Amount		Period (Years)
Customer relationships	$	120,000	$	(110,169)	$	9,831	6.0
License		750		(331)		419	10.0
Total intangible assets subject to amortization	$	120,750	$	(110,500)	$	10,250

	December 31, 2018
							Weighted-
							Average
	Gross Carrying		Accumulated		Net Carrying		Amortization
	Amount		Amortization		Amount		Period (Years)
Customer relationships	$	120,000	$	(91,756)	$	28,244	6.0
Licenses		3,368		(2,874)		494	5.6
Total intangible assets subject to amortization	$	123,368	$	(94,630)	$	28,738

Schedule of aggregate amortization expense

The aggregate amortization expense is as follows (in thousands):

	Year Ended December 31,
	2019		2018		2017
Amortization expense	$	18,488	$	26,163	$	31,232

Schedule of estimated aggregate amortization expense

The following table sets forth the Company’s estimated aggregate amortization expense for each of the five years below (in thousands):

	Amortization
Year ended December 31,	Expense
2020	$	9,906
2021		75
2022		75
2023		75
2024		75