LICENSE AGREEMENT WITH MGI PHARMA, INC./EISAI CORPORATION (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Net product sales:
Net product sales	$ 71,006	$ 70,869	$ 210,586	$ 187,116
Net product sales, Increase (Decrease)	137		23,470
Royalty revenue	16,995	16,638	52,030	45,148
Royalty Revenue, Increase (Decrease)	357		6,882
Net product sales, Increase (Decrease) (as a percent)	0.20%		12.50%
Royalty Revenue, Increase (Decrease) (as a percent)	2.10%		15.20%
North America
Net product sales:
Net product sales	55,751	60,180	168,837	155,255
Net product sales, Increase (Decrease)	(4,429)		13,582
Net product sales, Increase (Decrease) (as a percent)	(7.40%)		8.70%
Rest of the world
Net product sales:
Net product sales	15,255	10,689	41,749	31,861
Net product sales, Increase (Decrease)	4,566		9,888
Net product sales, Increase (Decrease) (as a percent)	42.70%		31.00%
MGI Pharma, Inc./EISAI Corporation | Dacogen
License agreement with MGI Pharma, Inc./Eisai Corporation
Period within which the entity is to receive royalty revenue			45 days
Period during which royalty revenue is recognized			45 days
Net product sales:
Royalty revenue	$ 16,995	$ 16,638	$ 52,030	$ 45,148
MGI Pharma, Inc./EISAI Corporation | Dacogen | Minimum
License agreement with MGI Pharma, Inc./Eisai Corporation
Royalty revenue (as a percent)	20.00%		20.00%
MGI Pharma, Inc./EISAI Corporation | Dacogen | Maximum
License agreement with MGI Pharma, Inc./Eisai Corporation
Royalty revenue (as a percent)	30.00%		30.00%