CONDENSED CONSOLIDATED INCOME STATEMENTS (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
CONDENSED CONSOLIDATED INCOME STATEMENTS
Net loss attributable to non-controlling interests, tax	$ 0.5	$ 0.4	$ 1.1	$ 0.8

This element represents the tax effect on the portion of income (loss) attributable to the non-controlling interest.

No definition available.

Name:	atni_NetIncomeAttributableToNoncontrollingInterestsTax
Namespace Prefix:	atni_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration