Stockholders'/Members' Equity - Additional Information (Detail)	Jun. 30, 2026 shares
Stockholders' Equity Note [Abstract]
Capital unit held	123,745,401
Percentage of ownership interest held in non controlling interest	61.10%

Percentage Of Ownership Interest Held In Non Controlling Interest.

No definition available.

Name:	mwh_PercentageOfOwnershipInterestHeldInNonControllingInterest
Namespace Prefix:	mwh_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant