Intangible Assets (Tables)

6 Months Ended

Jun. 30, 2017

Intangible Assets, Net (Excluding Goodwill) [Abstract]

Summary of Finite-Lived Intangible Assets

The following table summarizes our finite-lived intangible assets (in millions):

	June 30, 2017						December 31, 2016
	Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount
Intangible asset - sofosbuvir	$	10,720	$	2,505	$	8,215	$	10,720	$	2,156	$	8,564
Intangible asset - Ranexa	688		517		171		688		467		221
Other	455		290		165		455		269		186
Total	$	11,863	$	3,312	$	8,551	$	11,863	$	2,892	$	8,971

Schedule of Estimated Future Amortization Expense

As of June 30, 2017, the estimated future amortization expense associated with our finite-lived intangible assets is as follows (in millions):

Fiscal Year	Amount
2017 (remaining six months)	$	419
2018	850
2019	739
2020	713
2021	713
Thereafter	5,117
Total	$	8,551