CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (LOSS) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Other comprehensive income:
Changes in fair value of cash flow hedges, net of taxes of $111 and $0, respectively	$ (1,044)	$ (383)
Reclassification of unrealized losses on cash flow hedges to net income, net of taxes of $59 and $0, respectively	549	48
Reclassification of unrealized losses on available-for-sale securities to net income		495
Foreign currency translation adjustments, net of taxes of $13,732 and $642, respectively	27,427	36,909
Other comprehensive income	26,932	37,069
Comprehensive income	187,880	247,427
Comprehensive loss attributable to noncontrolling interest	8,831	18,814
Comprehensive income attributable to American Tower Corporation	196,711	266,241
Statement of Income and Comprehensive Income [Abstract]
Net income	$ 160,948	$ 210,358