Intangible assets and goodwill (Tables)

6 Months Ended

Jun. 30, 2017

The components of intangible assets as of June 30, 2017 were as follows (in thousands, except for useful life):


	Weighted-	Gross				Net
	Average Useful	Carrying		Accumulated		Carrying
	Lives (Years)	Amount		Amortization		Amount
Finite-lived intangible assets:
Licensed IP(1)	12.5	$	271,000	$	23,331	$	247,669
Indefinite-lived intangible assets:
Acquired IPR&D(1)	N/A		12,000		—		12,000
		$	283,000	$	23,331	$	259,669

(1) We acquired certain intangible assets as part of the Acquisition, as described further in Note 3.

Schedule of estimated aggregate amortization expense

Estimated aggregate amortization expense based on the current carrying value of amortizable intangible assets, excluding any possible future amortization associated with acquired IPR&D, for which development has not yet been completed, is as follows (in thousands):


		Remainder of
		2017		2018		2019		2020		2021		Thereafter
Amortization expense	$	10,768	$	21,536	$	21,536	$	21,536	$	21,536	$	150,757