Stock-based Compensation - Narrative (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Jun. 30, 2025	Sep. 30, 2026	Sep. 30, 2025	Dec. 31, 2016	Jan. 01, 2026	Jan. 01, 2025
2015 and 2016 and 2018 Equity Inducement Plan | Service Based Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based award, vesting period (in years)				4 years
Expiration term (in years)				10 years
2016 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Annual percentage of additional shares						5.00%
Additional number of shares available for issuance (in shares)							4,711,544	3,814,905
Common stock available for future issuance (in shares)	14,999,732			14,999,732
Outstanding option awards (in shares)	6,822,482			6,822,482
2018 Equity Inducement Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock available for future issuance (in shares)	6,164,834			6,164,834
Outstanding option awards (in shares)	5,735,274			5,735,274
Common stock available for future issuance, additional amount authorized (in shares)			750,000
2016 Employee Stock Purchase Plan | Employee Stock | 2016 ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares sold (in shares)	19,967	17,298		19,967	34,175
Sale of stock, proceeds received	$ 0.5	$ 0.2		$ 0.5	$ 0.6