Fair Value Hierarchy for Financial Assets Measured at Fair Value on a Recurring Basis (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, cash	$ 21.6	$ 20.6

Unrestricted cash available for day-to-day operating needs, for an entity that has cash equivalents, but does not aggregate cash equivalents with cash in this note disclosure

No definition available.

Name:	inap_CashAtCarryingValue
Namespace Prefix:	inap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant