CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (unaudited) (Parenthetical)	Jun. 29, 2011	Jun. 07, 2011
CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY [Abstract]
Net proceeds from sale of common stock (in shares)	8,912,372	8,912,372
Conversion of subordinated note to common stock (in shares)	491,830

Number of common stock shares as a result of the conversion of subordinated note.

No definition available.

Name:	mcbc_ConversionOfSubordinatedNoteToCommonStockShares
Namespace Prefix:	mcbc_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant