Other Current Assets- Additional Information (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Other Assets Current	$ 1,011	$ 902
Acute Myeloid Leukemia
Other Assets Current	700
Prepaid Expenses
Other Assets Current	1,000	$ 900
Other Prepaid Expenses
Other Assets Current	$ 300