Development and License Agreements - Summary of Amounts Payable and Amounts Receivable from Fresenius (Detail) - USD ($) $ in Thousands		Jun. 30, 2021	Dec. 31, 2020
Related Party Transactions [Abstract]
Payables to Fresenius	[1]	$ 18,852	$ 13,838
Non-trade receivables from Fresenius	[2]	$ 5,675	$ 2,380

[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.