Earnings Per Common Share (Details)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Earnings Per Common Share [Abstract]
Basic weighted average shares outstanding	190,086,000	162,398,000	150,963,000
Effect of common stock equivalents under incentive plans	819,000	812,000	309,000
Diluted weighted average shares outstanding	190,905,000	163,210,000	151,272,000
Effect of options to purchase common stock	2,600,000	2,500,000	2,200,000