| 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 table (in thousands, except amortization period):
| |
|
September 30, 2016 |
|
| |
|
Gross Carrying
Amount |
|
|
Accumulated
Amortization |
|
|
Net Carrying
Amount |
|
|
Weighted-
Average
Amortization
Period (Years) |
|
| Customer relationships |
|
$ |
120,000 |
|
|
$ |
(31,326 |
) |
|
$ |
88,674 |
|
|
|
6.0 |
|
| Licenses |
|
|
3,368 |
|
|
|
(631 |
) |
|
|
2,737 |
|
|
|
5.6 |
|
| Non-compete agreements |
|
|
660 |
|
|
|
(330 |
) |
|
|
330 |
|
|
|
1.0 |
|
| Total intangible assets subject to amortization |
|
$ |
124,028 |
|
|
$ |
(32,287 |
) |
|
$ |
91,741 |
|
|
|
|
|
| License (Indefinite-lived) |
|
$ |
4,427 |
|
|
$ |
— |
|
|
$ |
— |
|
|
|
|
|
| |
|
December 31, 2015 |
|
| |
|
Gross Carrying
Amount |
|
|
Accumulated
Amortization |
|
|
Net Carrying
Amount |
|
|
Weighted-
Average
Amortization
Period (Years) |
|
| Customer relationships |
|
$ |
120,000 |
|
|
$ |
(15,527 |
) |
|
$ |
104,473 |
|
|
|
6.0 |
|
| Backlog |
|
|
70,000 |
|
|
|
(70,000 |
) |
|
|
— |
|
|
|
1.0 |
|
| Licenses |
|
|
3,368 |
|
|
|
(208 |
) |
|
|
3,160 |
|
|
|
5.6 |
|
| Total intangible assets subject to amortization |
|
$ |
193,368 |
|
|
$ |
(85,735 |
) |
|
$ |
107,633 |
|
|
|
|
|
| License (Indefinite-lived) |
|
$ |
4,427 |
|
|
$ |
— |
|
|
$ |
— |
|
|
|
|
|
The aggregate amortization expense is as follows (in thousands):
| |
|
Three Months Ended
September 30, |
|
|
Nine Months Ended
September 30, |
|
| |
|
2016 |
|
|
2015 |
|
|
2016 |
|
|
2015 |
|
| Amortization expense |
|
$ |
5,601 |
|
|
$ |
20,951 |
|
|
$ |
16,552 |
|
|
$ |
60,172 |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
The following table sets forth the Company’s estimated aggregate amortization expense for each of the five years below (in thousands):
| Year ended December 31, |
|
Amortization
Expense |
|
| 2017 |
|
$ |
31,067 |
|
| 2018 |
|
|
26,163 |
|
| 2019 |
|
|
18,489 |
|
| 2020 |
|
|
9,906 |
|
| 2021 |
|
|
75 |
|
|