Development and License Agreements - Summary of Amounts Payable and Amounts Receivable from Fresenius (Detail) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018
Related Party Transactions [Abstract]
Payables to Fresenius	[1]	$ 8,470	$ 7,812
Receivables from Fresenius	[2]	$ 1,796	$ 1,777

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

[2] Included in “Prepaid and other current assets” in the Company's consolidated balance sheets.