Parent Company (Statements of Income) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed Financial Statements, Captions [Line Items]
Benefit from income taxes	$ (3,977)	$ (3,124)	$ (4,648)
NET INCOME	15,194	14,620	15,461
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Dividends from Merchants Bank	7,607	7,953	6,901
Equity in undistributed earnings of subsidiaries	8,721	7,832	9,705
Other expense, net	(1,743)	(1,788)	(1,760)
Benefit from income taxes	609	623	615
NET INCOME	$ 15,194	$ 14,620	$ 15,461