Accounts Payable and Accrued Expenses - Additional Information (Detail) $ in Millions	6 Months Ended
Jun. 30, 2021 USD ($)
Net decrease in accrued salaries and bonuses	$ 19.1

Increase (decrease) in accrued salaries and bonuses.

No definition available.

Name:	md_IncreaseDecreaseInAccruedSalariesAndBonuses
Namespace Prefix:	md_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration