Earnings Per Common Share (Tables)

3 Months Ended

Mar. 31, 2013

NET INCOME PER COMMON SHARE AMOUNTS:

Schedule of earnings per basic and diluted by common class

	Three Months Ended March 31,
	2013		2012
Income from continuing operations attributable to American Tower Corporation	$	171,407	$	221,306
Basic weighted average common shares outstanding		395,239		393,885
Dilutive securities		4,420		4,568
Diluted weighted average common shares outstanding		399,659		398,453
Basic income from continuing operations attributable to American Tower Corporation per common share	$	0.43	$	0.56
Diluted income from continuing operations attributable to American Tower Corporation per common share	$	0.43	$	0.56