Leases - Additional Information (Details) $ in Thousands	6 Months Ended
Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) lease
Leases [Abstract]
Number of leases not yet commenced \| lease		6
Leases not yet commenced, liability		$ 38,238
Impairment of right-of-use asset and accelerated operating expenses	$ (5,619)

Impairment of Right-Of-Use Asset And Accelerated Operating Expenses

No definition available.

Name:	mdca_ImpairmentOfRightOfUseAssetAndAcceleratedOperatingExpenses
Namespace Prefix:	mdca_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration