CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Treasury Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated deficit	Accumulated deficit Cumulative Effect, Period of Adoption, Adjustment
Beginning balance (in shares) at Dec. 31, 2019			51,704	(7,162)
Beginning balance at Dec. 31, 2019	$ 76,077	$ (768)	$ 5	$ (82,087)	$ 525,739	$ (33,261)	$ (334,319)	$ (768)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock based compensation	5,316				5,316
Issuance of restricted stock (in shares)			55
Issuance of restricted stock	0
Preferred stock dividends accrued	(8,158)				(8,158)
Amortization of preferred stock issuance costs	(750)				(750)
Shares withheld for taxes in connection with issuance of restricted stock (in shares)			(1)
Shares withheld for taxes in connection with issuance of restricted stock	0
Net income (loss) attributable to Synchronoss	(3,350)						(3,350)
Non-controlling interest	0				17		(17)
Total other comprehensive income (loss)	(3,562)					(3,562)
Ending balance (in shares) at Mar. 31, 2020			51,758	(7,162)
Ending balance at Mar. 31, 2020	$ 64,805		$ 5	$ (82,087)	522,164	(36,823)	(338,454)
Beginning balance (in shares) at Dec. 31, 2020	51,177		51,177	(7,162)
Beginning balance at Dec. 31, 2020	$ 43,282		$ 5	$ (82,087)	499,348	(28,213)	(345,771)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock based compensation	2,813				2,813
Issuance of restricted stock (in shares)			154
Issuance of restricted stock	0
Preferred stock dividends accrued	(9,407)				(9,407)
Amortization of preferred stock issuance costs	(1,123)				(1,123)
Net income (loss) attributable to Synchronoss	(12,366)						(12,366)
Non-controlling interest	0				(336)		336
Total other comprehensive income (loss)	$ (1,136)					(1,136)
Ending balance (in shares) at Mar. 31, 2021	51,331		51,331	(7,162)
Ending balance at Mar. 31, 2021	$ 22,063		$ 5	$ (82,087)	$ 491,295	$ (29,349)	$ (357,801)