Revenue Recognition - Product revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of revenue
Revenue	$ 64,399	$ 142,766	$ 171,349	$ 175,303
Activity in each of the product revenue allowance and reserve categories
Balance at the beginning			24,888	1,507
Provision related to current period sales			28,258	13,646
Adjustment related to prior period sales			(370)	62
Credit or payments made during the period			(41,977)	(10,217)
Balance at the end	10,799	4,998	10,799	4,998
Product revenue
Disaggregation of revenue
Revenue	63,612	41,755	170,312	72,723
ZEJULA
Disaggregation of revenue
Revenue	63,226	39,375	$ 165,989	65,321
ZEJULA | Europe
Disaggregation of revenue
Revenue percentage (in percent)			25.00%
VARUBI/VARUBY
Disaggregation of revenue
Revenue	386	2,380	$ 4,323	7,402
Licenses, collaboration and other revenues
Disaggregation of revenue
Revenue	787	101,011	1,037	102,580
Chargebacks, discounts and fees
Activity in each of the product revenue allowance and reserve categories
Balance at the beginning			2,088	177
Provision related to current period sales			13,052	6,567
Adjustment related to prior period sales			(268)
Credit or payments made during the period			(13,639)	(5,906)
Balance at the end	1,233	838	1,233	838
Government and other rebates
Activity in each of the product revenue allowance and reserve categories
Balance at the beginning			6,450	1,312
Provision related to current period sales			14,778	6,924
Adjustment related to prior period sales			(53)	62
Credit or payments made during the period			(12,667)	(4,311)
Balance at the end	8,508	3,987	8,508	3,987
Returns
Activity in each of the product revenue allowance and reserve categories
Balance at the beginning			16,350	18
Provision related to current period sales			428	155
Adjustment related to prior period sales			(49)
Credit or payments made during the period			(15,671)
Balance at the end	$ 1,058	$ 173	$ 1,058	$ 173