Consolidated Statement of Changes in Stockholders' Equity (Unaudited) (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Common stock per share dividend amount	$ 1.40	$ 1.40
Preferred stock
Shares of common stock issued upon conversion of Series B preferred stock		433,144
Common stock
Shares of common stock issued upon conversion of Series B preferred stock		433,144
Additional paid-in capital
Shares of common stock issued upon conversion of Series B preferred stock		433,144
Retained earnings
Common stock per share dividend amount	$ 1.40	$ 1.40
Treasury stock
Shares of common stock issued upon conversion of Series B preferred stock		433,144