Development and License Agreements - Summary of Amounts Payable and Amounts Receivable from Fresenius (Detail) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
Related Party Transactions [Abstract]
Payables to Fresenius	[1]	$ 8,262	$ 8,470
Receivables from Fresenius	[2]	$ 1,631	$ 1,796

[1] Included in “Accounts Payable” and “Accrued Liabilities” in the Company's condensed consolidated balance sheets.

[2] Included in “Other current assets” in the Company's condensed consolidated balance sheets.