Consolidated Statements of Stockholders' Equity (Parenthetical)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Consolidated Statements of Stockholders' Equity
Purchase of Common shares for Treasury	278,655	493	86,141
Issuance of Common shares, net of forfeitures	50,528	113,667	24,250