Intangible Assets and Goodwill - Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 213,603	$ 214,148
Accumulated Amortization	(105,476)	(69,438)
ASC 842 Adjustment	0	(540)
Total	108,127	144,170
Developed product rights for Auryxia
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	213,603	213,603
Accumulated Amortization	(105,476)	(69,433)
Total	$ 108,127	144,170
Favorable lease
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value		545
Accumulated Amortization		(5)
ASC 842 Adjustment		(540)
Total		$ 0