Consolidated Statements of Shareholders' Equity (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Issuance of common stock tax benefits	$ 60	$ 5	$ 16
Cash dividends	$ 0.72	$ 0.72	$ 0.72
Common Stock [Member]
Issuance of common stock tax benefits	60	5	16
Additional Paid-in Capital [Member]
Issuance of common stock tax benefits	$ 60	$ 5	$ 16
Retained Earnings [Member]
Cash dividends	$ 0.72	$ 0.72	$ 0.72