Composition of Total Revenue - Schedule of Net Product Sales by Product Line (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Sales Information [Line Items]
Product sales, net	$ 128,596	$ 136,851	$ 186,537
Fusilev [Member]
Sales Information [Line Items]
Product sales, net	34,839	60,710	105,608
FOLOTYN [Member]
Sales Information [Line Items]
Product sales, net	46,245	40,606	47,556
ZEVALIN [Member]
Sales Information [Line Items]
Product sales, net	10,730	17,457	22,169
MARQIBO [Member]
Sales Information [Line Items]
Product sales, net	7,245	8,006	6,328
BELEODAQ [Member]
Sales Information [Line Items]
Product sales, net	13,368	10,072	4,876
EVOMELA [Member]
Sales Information [Line Items]
Product sales, net	$ 16,169	$ 0	$ 0
Product Concentration Risk [Member] | Sales [Member]
Sales Information [Line Items]
Percentage of sales	100.00%	100.00%	100.00%
Product Concentration Risk [Member] | Sales [Member] | Fusilev [Member]
Sales Information [Line Items]
Percentage of sales	27.10%	44.40%	56.60%
Product Concentration Risk [Member] | Sales [Member] | FOLOTYN [Member]
Sales Information [Line Items]
Percentage of sales	36.00%	29.70%	25.50%
Product Concentration Risk [Member] | Sales [Member] | ZEVALIN [Member]
Sales Information [Line Items]
Percentage of sales	8.30%	12.80%	11.90%
Product Concentration Risk [Member] | Sales [Member] | MARQIBO [Member]
Sales Information [Line Items]
Percentage of sales	5.60%	5.90%	3.40%
Product Concentration Risk [Member] | Sales [Member] | BELEODAQ [Member]
Sales Information [Line Items]
Percentage of sales	10.40%	7.40%	2.60%
Product Concentration Risk [Member] | Sales [Member] | EVOMELA [Member]
Sales Information [Line Items]
Percentage of sales	12.60%	0.00%	0.00%