Condensed Consolidated Financial Statements - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013
Income Statement [Abstract]
Amount of settlement funds	$ 181.1

The balance of the settlement accounts at period end. Settlement accounts are trust accounts maintained for the benefit of the Company's clients. They are not included in the Company's balance sheet.

No definition available.

Name:	aciw_SettlementAccountsBalance
Namespace Prefix:	aciw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant