Regulatory Capital Requirements (Details) (USD $)	0 Months Ended
	Dec. 15, 2004	Dec. 31, 2012	Dec. 31, 2011
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier One Leverage Capital, Actual Amount		$ 136,004,000	$ 126,435,000
Tier One Leverage Capital, Actual Percent		8.08%	8.08%
Tier One Leverage Capital For Capital Adequacy Purposes, Amount		67,307,000	62,573,000
Tier One Leverage Capital For Capital Adequacy Purposes, Percent		4.00%	4.00%
Tier One Risk Based Capital, Actual Amount		136,004,000	126,435,000
Tier One Risk Based Capital, Actual Percent		14.75%	14.66%
Tier One Risk Based Capital For Capital Adequacy Purposes, Amount		36,887,000	34,490,000
Tier One Risk Based Capital For Capital Adequacy Purposes, Percent		4.00%	4.00%
Total Risk-Based Capital, Actual Amount		147,505,000	137,255,000
Total Risk-Based Capital, Actual Percent		16.00%	15.92%
Total Risk Based Capital For Capital Adequacy Purposes, Amount		73,753,000	68,981,000
Total Risk Based Capital For Capital Adequacy Purposes, Percent		8.00%	8.00%
Private placement, trust preferred securities, aggregate amount	20,000,000
Merchants Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier One Leverage Capital, Actual Amount		131,850,000	122,946,000
Tier One Leverage Capital, Actual Percent		7.81%	7.84%
Tier One Leverage Capital For Capital Adequacy Purposes, Amount		67,494,000	62,740,000
Tier One Leverage Capital For Capital Adequacy Purposes, Percent		4.00%	4.00%
Tier One Leverage Capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount		84,367,000	78,425,000
Tier One Leverage Capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Percent		5.00%	5.00%
Tier One Risk Based Capital, Actual Amount		131,850,000	122,946,000
Tier One Risk Based Capital, Actual Percent		14.21%	14.16%
Tier One Risk Based Capital For Capital Adequacy Purposes, Amount		37,123,000	34,723,000
Tier One Risk Based Capital For Capital Adequacy Purposes, Percent		4.00%	4.00%
Tier One Risk Based Capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount		55,684,000	52,084,000
Tier One Risk Based Capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Percent		6.00%	6.00%
Total Risk-Based Capital, Actual Amount		143,422,000	133,837,000
Total Risk-Based Capital, Actual Percent		15.45%	15.42%
Total Risk Based Capital For Capital Adequacy Purposes, Amount		74,245,000	69,446,000
Total Risk Based Capital For Capital Adequacy Purposes, Percent		8.00%	8.00%
Total Risk Based Capital To Be Well-Capitalized Under Prompt Corrective Action Provisions, Amount		$ 92,806,000	$ 86,807,000
Total Risk Based Capital To Be Well-Capitalized Under Prompt Corrective Action Provisions, Percent		10.00%	10.00%