Net Product Sales by Geographic Region, Product Line, and Gross Product Sales by Significant Customers - Schedule of Net Product Sales by Product Line (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Sales Information [Line Items]
Net product sales	$ 136,851	$ 186,537	$ 143,475
Fusilev [Member]
Sales Information [Line Items]
Net product sales	60,710	105,608	68,397
FOLOTYN [Member]
Sales Information [Line Items]
Net product sales	40,606	47,556	44,370
ZEVALIN [Member]
Sales Information [Line Items]
Net product sales	17,457	22,169	29,393
MARQIBO [Member]
Sales Information [Line Items]
Net product sales	8,006	6,328	1,315
BELEODAQ [Member]
Sales Information [Line Items]
Net product sales	$ 10,072	$ 4,876	$ 0
Product Concentration Risk [Member] | Sales [Member]
Sales Information [Line Items]
Percentage of net product sales	100.00%	100.00%	100.00%
Product Concentration Risk [Member] | Sales [Member] | Fusilev [Member]
Sales Information [Line Items]
Percentage of net product sales	44.40%	56.60%	47.70%
Product Concentration Risk [Member] | Sales [Member] | FOLOTYN [Member]
Sales Information [Line Items]
Percentage of net product sales	29.70%	25.50%	30.90%
Product Concentration Risk [Member] | Sales [Member] | ZEVALIN [Member]
Sales Information [Line Items]
Percentage of net product sales	12.80%	11.90%	20.50%
Product Concentration Risk [Member] | Sales [Member] | MARQIBO [Member]
Sales Information [Line Items]
Percentage of net product sales	5.90%	3.40%	0.90%
Product Concentration Risk [Member] | Sales [Member] | BELEODAQ [Member]
Sales Information [Line Items]
Percentage of net product sales	7.40%	2.60%	0.00%