Earnings per Share - Summary of Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator [Abstract]
Net loss	$ (94,666)	$ (32,435)	$ (202,066)	$ (52,915)
Less: Net loss attributable to noncontrolling interests subsequent to the Reorganization Transactions	(67,867)	$ 0	(146,017)	$ 0
Net loss attributable to SDC Inc. - basic	(26,799)		(56,049)
Add: Reallocation of net loss attributable to noncontrolling interests after the Reorganization Transactions from the assumed exchange of LLC Units for Class A common stock	(67,867)		(146,017)
Net loss attributable to SDC Inc. - diluted	$ (94,666)		$ (202,066)
Denominator [Abstract]
Weighted average shares of Class A common stock outstanding - basic (in shares)	109,048,411		106,819,870
Add: Dilutive effects as shown separately below (in shares)	276,084,892		277,672,758
Weighted average shares of Class A common stock outstanding - diluted (in shares)	385,133,303		384,492,628
Earnings per share of Class A common stock, basic (in USD per share)	$ (0.25)		$ (0.52)
Earnings per share of Class A common stock, diluted (in USD per share)	$ (0.25)		$ (0.53)