Net Income (Loss) per Share - Additional Information (Detail) - USD ($) $ in Thousands		1 Months Ended
Oct. 15, 2020	Oct. 31, 2021	Sep. 30, 2021	Sep. 30, 2020
Number of options outstanding			5,974,549	5,265,642
Number of restricted stock units outstanding			365,029	272,000
Vifor International Ltd. [Member] \| Regulatory Milestones [Member]
Stock Issued During Period Shares New Issues		3,282,391
Potential milestone payment	$ 50,000
Percentage of premium on common stock investment	20.00%	20.00%
Stock issuance price measurement period	30 days	30 days

The amount of potential milestone payment of common stock investment.

No definition available.

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- Definition

The premium related to the common stock investment upon regulatory approval of CR845.

+ References

No definition available.

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- Definition

The length of time used to set the price in the common stock investment upon regulatory approval of CR845.

+ References

No definition available.

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

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- Definition

Number of options outstanding, including both vested and non-vested options.

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- Definition

Number of new stock issued during the period.

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