Financial Statements (Details Textual) (USD $)	3 Months Ended	9 Months Ended
	Sep. 30, 2010	Sep. 30, 2010	Dec. 31, 2010
Financial Statements [Abstract]
Amount of the effect of a change in accounting principle on revenues	$ 35,141,000	$ 128,504,000
Amount of the effect of a change in accounting principle on income from continuing operations	2,644,000	29,605,000
Amount of the effect of a change in accounting principle on net income	2,752,000	32,890,000
Amount of the effect of a change in accounting principle per diluted share	$ 0.01	$ 0.06
Amount of the effect of a change in accounting principle on income from continuing operations per diluted share	$ 0.01	$ 0.06
Amount of the effect of a change in accounting principle on income reinvested			$ 8,722,000