Consolidated Statements of Shareholders' Equity (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 Accumulated other comprehensive income (loss)	Dec. 31, 2012 Accumulated other comprehensive income (loss)	Dec. 31, 2011 Accumulated other comprehensive income (loss)	Dec. 31, 2013 Reinvested earnings	Dec. 31, 2012 Reinvested earnings	Dec. 31, 2011 Reinvested earnings	Dec. 31, 2013 Capital in excess of par value	Dec. 31, 2012 Capital in excess of par value	Dec. 31, 2011 Capital in excess of par value
Tax effect on employee benefit funded status adjustment	$ (3,826)	$ (247)	$ 835
Cash dividends (in dollars per share)				$ 0.7	$ 0.66	$ 0.6
Issuance of treasury stock (in shares)							35	42	41