Note 10 - Regulatory Matters (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended						3 Months Ended	12 Months Ended			3 Months Ended	33 Months Ended		1 Months Ended
	Dec. 31, 2009	Sep. 30, 2009	Jun. 30, 2010 Compliance [Member] Farmers Bank [Member]	Mar. 31, 2012 Compliance [Member] United Bank [Member]	Dec. 31, 2010 Compliance [Member] Citizens Northern [Member]	Sep. 30, 2010 Compliance [Member] Citizens Northern [Member]	Dec. 31, 2009 Farmers Bank [Member]	Dec. 31, 2010 Farmers Bank [Member]	Jun. 30, 2012 Farmers Bank [Member]	Dec. 31, 2011 Farmers Bank [Member]	Mar. 31, 2012 United Bank [Member]	Jun. 30, 2012 United Bank [Member]	Dec. 31, 2011 United Bank [Member]	Dec. 31, 2010 Citizens Northern [Member]	Jun. 30, 2012 Citizens Northern [Member]	Dec. 31, 2011 Citizens Northern [Member]
Common Stock, Dividends, Per Share, Declared (in Dollars per share)	$ 0.10	$ 0.25
Tier One Leverage Capital to Average Assets			8.00%	9.00%	8.00%	7.50%			9.94%	9.47%		9.22%	8.44%	8.04%	8.74%	8.48%
Payments for (Proceeds from) Other Investing Activities (in Dollars)							$ 11,000	$ 200			$ 2,500	$ 18,900		$ 250
Capital to Risk Weighted Assets				13.00%					19.46%	18.84%		16.05%	14.79%		13.99%	13.49%