Firstbank Corporation Consolidated Statements of Changes in Shareholders’ Equity (Parentheticals) (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Cash dividends on common stock per share (in Dollars per share)	$ 0.07	$ 0.04
Shares of common stock issued through the dividend reinvestment plan	13,765	11,610
Shares of common stock issued from supplemental shareholder investments	1,601	34,803
Shares of common stock issued	37,795	42,379
Tax on net change in unrealized gain/(loss) on securities available for sale (in Dollars)	$ 444	$ 1,417
Shares of preferred stock redeemed	16,000
Common Stock [Member]
Cash dividends on common stock per share (in Dollars per share)	$ 0.07	$ 0.04
Shares of common stock issued through the dividend reinvestment plan	13,765	11,610
Shares of common stock issued from supplemental shareholder investments	1,601	34,803
Shares of common stock issued	37,795	42,379
Preferred Stock [Member]
Shares of preferred stock redeemed	16,000
Accumulated Other Comprehensive Income (Loss) [Member]
Tax on net change in unrealized gain/(loss) on securities available for sale (in Dollars)	$ 444	$ 1,417