Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Deferred compensation plan held Rabbi Trust	33,722	33,461
Shares issued under the performance incentive plan withheld for employee taxes	10,411	5,670
Cash Dividends Declared Per Share of Common Stock	$ 0.365	$ 1.440