SEVERANCE COSTS (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
SEVERANCE COSTS.
Severance and early retirement program costs	$ 29mas_SeveranceAndRetirementCosts	$ 20mas_SeveranceAndRetirementCosts	$ 35mas_SeveranceAndRetirementCosts

Represents one-time severance and early retirement costs that are not part of a restructuring plan nor associated with a discontinued operation.

No definition available.

Name:	mas_SeveranceAndRetirementCosts
Namespace Prefix:	mas_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration