Mundipharma Agreement And Drug Development Liability - Schedule of Drug Development Liability Adjustments (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2016 USD ($)
Accrued Drug Development Expenses [Roll Forward]
Balance at December 31, 2015	$ 259
Balance at June 30, 2016	156
FOLOTYN [Member]
Accrued Drug Development Expenses [Roll Forward]
Balance at December 31, 2015	14,686
Transfer from long-term to current in 2016	0
(Less): Expenses incurred in 2016	(303)
Balance at June 30, 2016	14,383
FOLOTYN [Member] | Drug Development Liability Current [Member]
Accrued Drug Development Expenses [Roll Forward]
Balance at December 31, 2015	259
Transfer from long-term to current in 2016	200
(Less): Expenses incurred in 2016	(303)
Balance at June 30, 2016	156
FOLOTYN [Member] | Drug Development Liability Long Term [Member]
Accrued Drug Development Expenses [Roll Forward]
Balance at December 31, 2015	14,427
Transfer from long-term to current in 2016	(200)
(Less): Expenses incurred in 2016	0
Balance at June 30, 2016	$ 14,227