Intangible assets and goodwill (Tables)

9 Months Ended

Sep. 30, 2018

Intangible assets and goodwill

Schedule of intangible assets, net

The components of intangible assets were as follows (in thousands, except for useful life):

Balance at September 30, 2018

Balance at December 31, 2017

Weighted-

Gross

Net

Gross

Net

Average Useful

Carrying

Accumulated

Carrying

Carrying

Accumulated

Carrying

Lives (Years)

Amount

Amortization

Amount

Amount

Amortization

Amount

Finite-lived intangible assets:

Licensed IP

12.5

$

271,000

$

50,252

$

220,748

$

271,000

$

34,099

$

236,901

Schedule of estimated aggregate amortization expense

Estimated aggregate amortization expense based on the current carrying value of amortizable intangible assets is as follows (in thousands):

		Remainder of
		2018		2019		2020		2021		2022		Thereafter
Amortization expense	$	5,383	$	21,536	$	21,536	$	21,536	$	21,536	$	129,221