Consolidated Statement of Shareholders' Equity (Unaudited) (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Tax on pension liability	$ 80	$ 339	$ 0
Dividends declared per share (in dollars per share)	$ 0.32	$ 0.28	$ 0.26
Accumulative Other Comprehensive Income (Loss) [Member]
Tax on pension liability	$ 80	$ 339
Retained Income (Deficit) [Member]
Dividends declared per share (in dollars per share)	$ 0.32	$ 0.28	$ 0.26