Statements of Shareholders' Equity (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Issuance of common shares for stock options exercised	9,857	8,059
Preferred stock dividends per share	$ 5.00	$ 5.00
Common stock dividends per share	$ 0.16	$ 16
Common Stock [Member]
Issuance of common shares for stock options exercised	9,857	8,059
Additional Paid-in Capital [Member]
Issuance of common shares for stock options exercised	9,857	8,059
Retained Earnings [Member]
Preferred stock dividends per share	$ 5.00	$ 5.00
Common stock dividends per share	$ 0.16	$ 16