Goodwill and Intangible Assets (Tables)

3 Months Ended

Mar. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

The gross carrying amount of goodwill was as follows (in thousands):



Balance at December 31, 2016	$	893,810
Foreign exchange	5,480
Balance at March 31, 2017	$	899,290

Gross Carrying Amounts and Net Book Values of Intangible Assets

The gross carrying amounts and net book values of our intangible assets were as follows (in thousands):



	March 31, 2017								December 31, 2016
	Remaining Weighted- Average Useful Life (In years)	Gross Carrying Amount		Accumulated Amortization			Net Book Value		Gross Carrying Amount		Accumulated Amortization			Net Book Value
Acquired developed technologies	11.1	$	1,491,720	$	(438,983	)	$	1,052,737	$	1,477,618	$	(410,523	)	$	1,067,095
Manufacturing contracts	0.8	11,434		(9,121		)	2,313		11,278		(8,292		)	2,986
Trademarks	—	2,876		(2,876		)	—		2,872		(2,872		)	—
Total finite-lived intangible assets		1,506,030		(450,980		)	1,055,050		1,491,768		(421,687		)	1,070,081
Acquired in-process research and development assets		1,943,730		—			1,943,730		1,941,920		—			1,941,920
Total intangible assets		$	3,449,760	$	(450,980	)	$	2,998,780	$	3,433,688	$	(421,687	)	$	3,012,001

Estimated Future Amortization Costs

Based on finite-lived intangible assets recorded as of March 31, 2017, and assuming the underlying assets will not be impaired and that we will not change the expected lives of the assets, future amortization expenses were estimated as follows (in thousands):



Year Ending December 31,	Estimated Amortization Expense
2017 (remainder)	$	77,309
2018	100,336
2019	100,123
2020	98,980
2021	98,044
Thereafter	580,258
Total	$	1,055,050