Consolidated Statements of Equity (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Treasury Shares
Purchase of treasury shares	0	85	0
Additional Paid-in Capital
Income tax on stock option exercise and other shares issued to employees and directors	710	1,197	1,076
Stock option exercises and other shares issued to employees and directors, shares	143	150	157
Retained Earnings
Dividends declared, per common share	0.60	0.4810	0.3575