Organization and Business (Details) - segment	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	May 12, 2020	Oct. 30, 2019
Business And Organization [Line Items]
Number of reportable segments	3
DBMG
Business And Organization [Line Items]
Parents interest, controlling (approximately)	90.00%
Genoval Orthopedics inc.
Business And Organization [Line Items]
Parents interest, controlling (approximately)	80.00%
R2 Technologies, Inc.
Business And Organization [Line Items]
Parents interest, controlling (approximately)	56.00%
MediBeacon Inc.
Business And Organization [Line Items]
Parents interest, controlling (approximately)	47.00%
HC2 Broadcasting Holdings, Inc
Business And Organization [Line Items]
Parents interest, controlling (approximately)	98.00%
DTV America
Business And Organization [Line Items]
Parents interest, controlling (approximately)	76.00%	60.00%
Minority Holders
Business And Organization [Line Items]
Percentage of proxy and voting rights from minority holders	10.00%	10.00%
GMSL
Business And Organization [Line Items]
Parents interest, controlling (approximately)	73.00%		30.00%	49.00%
HMN
Business And Organization [Line Items]
Parents interest, controlling (approximately)	19.00%