Net Loss per Share - Schedule of Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Numerator:
Net loss	$ (69,652)	$ (70,253)	$ (38,136)	$ (39,805)	$ (139,905)	$ (77,941)
Net loss attributable to non-controlling interest	(507)		(277)		(723)	(894)
Net loss attributable to American Well Corporation	$ (69,145)		$ (37,859)		$ (139,182)	$ (77,047)
Denominator:
Weighted-average common shares outstanding, basic	273,320,740		249,366,652		273,615,031	246,471,733
Weighted-average common shares outstanding, diluted	273,320,740		249,366,652		273,615,031	246,471,733
Net loss per share attributable to common stockholders, basic	$ (0.25)		$ (0.15)		$ (0.51)	$ (0.31)
Net loss per share attributable to common stockholders, diluted	$ (0.25)		$ (0.15)		$ (0.51)	$ (0.31)